We Only Eat What We Like – the complete article and download
A few months ago, my friend Michel Oliver, great chef, superb winemaker and successful author of cooking books for children (and adults), told me a story:
“A few years ago, on a sand beach with big surf, a little boy was flying his kite. He was running with the wind on the sand. He noticed, far away on the beach, a silhouette; he ran closer. Then he saw, on the wet sand, miraculously beautiful portraits, plants, fortresses, women dancing, a huge gallery of dreams as art. The little boy was transfixed, mesmerized; his jaw was falling; his eyes filled with tears of joy. This was his epiphany.
He walked along these marvels –one more strikingly beautiful than the other- and saw that the genius who had drawn those in the sand was an old man. He wanted to tell him…and then a huge wave erased everything. The man stood up, and left; he was Pablo Picasso”.
Chinese historian and philosopher Tu Weiming states  that “the distinctiveness of being human lies in continuity with, rather than rupture from Heaven, Earth, and the myriad things”. He then says: “The body so conceived is an attainment. We do not own our bodies. We become our bodies; as we learn to sit, stand, walk, run, and talk, we are empowered to express ourselves through our bodies. Although ontologically we are our bodies, in an existential sense, we must learn to become our bodies. The Confucian idea of the living body as the primary datum and an irreducible reality is diametrically opposed to the Cartesian view that the body, contrasted with the thinking mind, is not essential for self-identity. For the Confucians, the body is the proper home for the heart-and-mind. Furthermore, the heart-and-mind manifests itself through the lived body and expresses its true nature by the experiences and feelings of the body. This is the reason that Mencius asserted that only the sage could bring the bodily form to fruition: ‘Our body and complexion are given to us by Heaven. Only a sage can give his body complete fulfillment.’”
This, I suggest, is commensurability
“We are what we eat”…and drink. What patients eat, drink, consume will either help or worsen their condition. Food is medicine, and many medicines were (are) foods, as we know from the Asian traditions. But the single one major variable that never appears in any medical study is the role of pleasure.
One of the major foods consumed in Western (and other) societies is bread; it is a basic, tradition-filled, and inexpensive food item. And since it is part of our daily intake, the industry has for decades focused on its quality to make it whiter, sweeter, softer, toast-able, never-to-rot, and –above all- bland. Bread is more and more an anonymous, cardboard-tasting support for “no-cholesterol” artificially colored spread-able concoctions. But traditional bread does exist: it is crusty, tasty, flavorful, quite rich in fiber and magnesium, wholesome, and basic: wheat flour, leaven, water, salt –and the loving art of the baker. The best baker in the world –so declared Smithsonian magazine- was my friend Lionel Poilâne. His bread is “rich in selenium [Halpern et al.1992; Olin et al. 1994] and magnesium; its salt is harvested in Guérande, tastes like violet, and provides iodine and magnesium; the natural leaven (starter of sourdough) results in better taste and digestibility, and is a precious source of vitamins. Poilâne supports sustainable farming: no nitrates, no pesticides, and his bread is hand made. The loaves are baked in Poilâne wood-heated oven (XIXth century) [www.poilane.com]. But this description does NOT bring back the flavor, the crustiness, the texture, the taste, the pleasure you experienced when you bate into this large toasted tartine of Poilâne’s bread… Medical articles miss the emotional, rewarding dimension.
Stress vs. pleasure:
The notion that stress makes you sick and belief makes you well has been part of the popular culture for thousands of years. These ideas are universal throughout the cultures. In Western culture this notion held away from before the time of Hippocrates, when the Greeks built temples to Asclepios, the god of healing, all the way through the modern times when Norman Cousins and Norman Vincent Peale have espoused the idea that laughter and positive thinking heals [Steinberg 2000]. But recent studies [Leonard 2000] cast doubts on previous assumptions pointing to hypercortisolemia causing immune suppression. It is now apparent that adaptive changes result from chronic stress and depression that lead to a hypoactivity of the glucocorticoid receptors on immune cells and in limbic regions of the brain. Depression and anhedonia are associated with hypersecretion of proinflammatory cytokines and hyperactivity of the hypothalamic-pituitary-adrenal axis. Moreover stress impacts health by modulating the rate of cellular aging [Epel et al. 2004]. There is now evidence that psychological stress –both perceived stress and chronicity of stress- is significantly associated with higher oxidative stress, lower telomerase activity, and shorter telomere length, which are known determinants of cell senescence and longevity, in healthy premenopausal women. Women with the highest level of perceived stress have telomeres shorter on average by the equivalent of at least one decade (9-17y) of additional aging compared to low stress women! The observation of people aging suddenly after major psychological stress, e.g. bombing of Dresden on February 13, 1945, has now a biological confirmation.
The brain talks directly to the immune system, sending commands that control the body’s inflammatory response to infection and autoimmune diseases; Kevin J. Stacey has demonstrated that stimulation of the vagus nerve (through the release of acetylcholine) could block a rogue inflammatory response and treat a number of diseases, including life-threatening sepsis, inflammatory bowel disease, rheumatoid arthritis, type 2 diabetes, and other conditions of excessive cytokine release. It also enables consideration of the neurological basis of complementary and alternative medical therapies, such as meditation and acupuncture. He calls this network “the inflammatory reflex” [Oke et al. 2007].
Pleasantness is the principal perceptual aspectof olfaction; it is the primary perceptual aspect humansuse to discriminate odorants or combine them into groups. Pleasant and unpleasant odorants are evaluatedat different speeds and by dissociableneural substrates, as evidenced in both electrophysiologicalrecordings and functional neuroimaging studies. Studies with newbornssuggest that at least some aspects of olfactory pleasantnessmay be innate. Itis clearly the hedonic meaning of odor that dominates odor perception. When one orders aset of odorants based on the variance in their physicochemicalproperties alone, they end up roughly ordered by perceptualpleasantness as well. This phenomenon allows to predict(r = 0.5; p < 0.004) odorant pleasantness of >50 moleculesthat one did not smell previously and that were tested in >80 subjectsspanning three cultures. The olfactory system is known for plasticity at multiplelevels, which reflects an advantageousevolutionary mechanism. To automatically reject food that smellsfermented is generally a safe bet. However, if through experienceone learns that exceptions exist, and for example fermentedfish can be both tasty and healthy, than its pleasantness representationmay shift. This is what allows Swedes to enjoy their SurströmmingHerring (a dish not for the faint of heart), although even theywill not say they like the odor per se. Finally in this respect,it is notable that although the predictive power for pleasantnessis significant (p < 0.004), this explains only a portionof the variance. This leaves open the possibility that individualdifferences and plasticity in olfactory hedonics make importantcontributions to olfactory perception [Khan et al. 2007].
And the pleasure of eating is associated with well-being: Individuals who were both high on pleasure associated with eating and high on restraint showed the lowest self-clarity and the highest neuroticism scores, while the opposite pattern was found for those high on pleasure but low on restraint. Restrained eating affects well-being [Remick et al. 2009]. Conversely –and apparently paradoxically- morbid thoughts whet appetite: consumers who wrote about their own deaths wanted to buy more and ate more than those who wrote about a painful medical procedure (control group). Consumers, especially those with a lower self esteem, might be more susceptible to over-consumption when faced with images of death during the news or their favorite crime-scene investigation shows [Mandel et al. 2008].
Never underestimate pleasure:
In 1991, I published a study demonstrating that live active culture (LAC) yogurt consumption is associated with a five-fold increased production of gamma-interferon (γ-IFN) by PBMC [Halpern et al. 1991].Then, in 1993, we demonstrated that regular consumption of LAC yogurt –but not “heat-killed” yogurt- over the course of one year resulted in a significant reduction of the number of days during which the subjects suffered on symptoms of allergic (pollen) rhinitis [Trapp et al. 1993]. But in 1997 I went back to the subjects’ files and redid some calculations, and conducted interviews; I found that
our “best” responders, i.e. subjects who demonstrated the highest levels of γ-IFN, in the LAC yogurt groups, were the most creative for delicious recipes of smoothies and yogurt shakes.
“The pleasures of the table are for every man, of every land, and no matter of what place in history or society; they can be a part of all other pleasures and they last the longest, to console us when we have outlived the rest” [Brillat-Savarin 1825].
Food is (much) more than nutrition. The value of food intake on social patterns, self-esteem, pleasure and enjoyment impacts quality of life. While nutrition can provide the basic need for nutrients, the loss of the eating function is a distressing experience, especially given the cultural focus on social gatherings and meals [Winkler 2007].
The Pleasure of/with Meals:
“The primary requisite for writing well about food is a good appetite. Without this, it is impossible to accumulate within the allotted span, enough experience of eating to have anything worth setting down. Each day brings only two opportunities for field work, and they are not to be wasted minimizing the intake of cholesterol” [Liebling 1959].
Food intake is an essential human activity regulated by homeostatic and hedonic systems in the brain that has mostly been ignored by the cognitive neurosciences. It was probably too trivial, too banal, or even sinful. Yet the study of food intake integrates fundamental cognitive and emotional processes in the human brain, and can provide evidence on the neural correlates of the hedonic experience central to guiding behavior. This hedonic experience is related to qualia, which has been described as “the hard problem of consciousness” [Chalmers 1995]. Fortunately, recently neuroimaging [Kingelbach 2004] has identified the medial anterior part of the orbitofrontal cortex as the strongest candidate for linking food to hedonic experience [De Araujo et al. 2003]. Pleasant, but not unpleasant odors were found to activate a medial region of the rostral orbitofrontal cortex [Rolls et al. 2003]; other candidate brain regions such as the anterior cingulated, the insular cortex and ventral striatum could be part of hedonic networks in the human brain.
But what about patients subjected to hospital fare after surgery? In a seminal study, Marian Apfelbaum  demonstrated that artsy and tasting food shortens hospital stay of surgical patients by an average of 3 days. All constituents/calories were identical in both the abject diet provided by the central hospital kitchen, and the elaborate dishes shining on china produced by a dietician-turned-chef.
Why is that? The group of Apfelbaum [Melchior et al. 1994] tested the effect of the palatability of a meal on the post-prandial release of several gut hormones or neuropeptides that are known to have an effect on intake and satiety. Hormonal response was determined in plasma during the 3 h after a highly palatable and energy-rich meal, or after the same meal served cold in a poorly acceptable form, as well as while fasting. The early post-prandial pancreatic polypeptide and neurotensin response was significantly higher after the highly palatable meal than after the cold one. Post-prandial levels of beta-endorphin were elevated only after the cold meal and were associated with an elevated response of ACTH, a marker of stress. J.C. Melchior et al. suggest that beta-endorphin might be secreted in response to an aversion towards the non-palatable cold meal. This could, subsequently, inhibit the cephalic phase of pancreatic polypeptide response and the early post-prandial response of neurotensin by a central anticholinergic effect. That study evidenced an effect of palatability on the modulation of the digestive hormonal response after a meal.
Food intake is a regulated system. Afferent signals provide information to the central nervous system, which is the center for the control of satiety or food seeking. Such signals can begin even before food is ingested through visual, auditory and olfactory stimuli. One of the recent interesting findings is the demonstration that there are selective fatty acid taste receptors on the tongue. CCK inhibits food intake in human subjects. Enterostatin, the pentapeptide produced when pancreatic colipase is cleaved in the gut, has been shown to reduce food intake. This peptide differs in its action from CCK by selectively reducing fat intake. Enterostatin reduces hunger ratings in human subjects. Bombesin and its human analogue, gastrin inhibitory peptide (also gastrin-insulin peptide), reduce food intake in obese and lean subjects. Circulating glucose concentrations show a dip before the onset of most meals in human subjects. When the glucose dip is prevented, the next meal is delayed. The dip in glucose is preceded by a rise in insulin, and stimulating insulin release will decrease circulating glucose and lead to food intake. Leptin released from fat cells is an important peripheral signal from fat stores that modulates food intake. Leptin deficiency or leptin receptor defects produce massive obesity. This peptide signals a variety of central mechanisms by acting on receptors in the arcuate nucleus and hypothalamus. Pancreatic hormones including glucagon, amylin and pancreatic polypeptide reduce food intake. Four pituitary peptides also modify food intake. Vasopressin decreases feeding. In contrast, injections of desacetyl melanocyte-stimulating hormone, growth hormone and prolactin are associated with increased food intake. Finally, there are a group of miscellaneous peptides that modulate feeding. Beta-casomorphin, a heptapeptide produced during the hydrolysis of casein, stimulates food intake in experimental animals. In contrast, the other peptides in this group, including calcitonin, apolipoprotein A-IV, the cyclized form of histidyl-proline, several cytokines and thyrotropin-releasing hormone, all decrease food intake. Many of these peptides act on gastrointestinal or hepatic receptors that relay messages to the brain via the afferent vagus nerve [Bray 2000].
Preferences and Prejudices about Food:
On these days of mega mergers among the manufacturers and carriers of information –and education-, the tendency to “unify”, i.e. make monotony the gold standard, is an Orwellian reality. And it can grow on fertile ground: two studies explored Americans’ tendency to simplify nutrition information [Rozin et al. 1996]. Substantial minorities of separate samples of college students, physical plant workers, and a national sample considered a variety of substances, including some essential nutrients [salt and fat], to be harmful at trace levels. Almost half the respondents believed that high-calorie foods in small amounts contained more calories than low-calorie foods in much larger amounts. Many subjects classified foods according to a good/bad dichotomy, and almost all subjects confounded nutritional completeness with long-term healthfulness of foods. To account for these results, the authors suggest the following heuristics and biases: dose insensitivity, categorical perception, a “monotonic mind” belief (if something is harmful at high levels it is harmful at low levels), and the magical principle of contagion.
But what about other human beings for whom food is a critical contributor to physical well being, a major source of pleasure, worry and stress, a major occupant of waking time, and, across the world, the single greatest category of expenditures? Paul Rozin published in 1999 [Rozin et al. 1999] the first study on the way food functions in the minds and lives of people from four cultures. Adults and college students from Flemish Belgium, France, U.S.A. and Japan were surveyed with questions dealing with beliefs about the diet-health link, worry about food, the degree of consumption of foods modified to be “healthier” (e.g. reduced in salt or fat), the importance of food as a positive force in life, the tendency to associate foods with nutritional vs. culinary contexts, and satisfaction with the healthiness of one’s own diet. In all domains except beliefs about the importance of diet for health, there are substantial country (and usually gender) differences. Generally the group associating food most with health and least with pleasure is the Americans, and the group most food-pleasure-oriented and least food-health-oriented is the French. In all four countries, females, as opposed to males, show a pattern of attitudes that is more like the American pattern, and less like the French pattern. In either gender, French and Belgians tend to occupy the pleasure extreme, Americans the health extreme, with the Japanese in between. Ironically, the Americans, who do the most to alter their diet in the service of health, are the least likely to classify themselves as healthy eaters. These differences may influence health and may partially account for differences in rates of cardiovascular diseases, a.k.a. the “French paradox”.
But why do we like fat [Drewnowski 1997]? Dietary choices are strongly influenced by the taste and texture of foods. Fats are responsible for the sensory properties of many foods and greatly contribute to eating pleasure. Although diets rich in fats tend to be more flavorful and varied, they also are high in energy. Because excessive fat consumption has been associated with higher rates of obesity and coronary heart disease, nutrition education efforts have focused on replacing dietary fats with grains, vegetables, and fruit. However, preference for high-fat foods appears to be a universal human trait, and in the absence of efficient physiologic mechanisms regulating fat intake, fat consumption appears to be determined simply by the amount of fat available in the food supply. Fat consumption at national levels is determined largely by economic variables such as urbanization or income. The question is whether appropriate nutrition education and intervention programs can surmount these barriers; but facing the humungous ever-present incitation of the fat-laden food industry we should remain skeptical about the success rate of such programs.
Good Digestion of Pleasurable Food may Prevent Cancer, and Alleviates Pain:
A group of the University of Leiden, in the Netherlands, studied the effect of vasoactive intestinal peptide (VIP), peptide histidine-methionine (PHM), and secretin on spontaneous cell-mediated cytotoxicity of peripheral blood mononuclear cells against tumor target cells [van Tol et al. 1991]. VIP stimulated cytotoxicity against CaCo-2 human colon cancer cells, whereas less effect was seen against K-562 erythroleukemia cells. Depletion of CD16+ natural killer cells almost completely abolished cytotoxicity and subsequent VIP incubation did not change residual activity. In contrast to
PHM, which hardly influenced cytotoxicity, secretin was found to be more effective especially against K-562 target cells. These observations suggest a modulating role for the neuropeptide VIP in the cellular immune response against tumor cells, especially from the colon, resulting in increased activity of CD16+ natural killer cells. Secretin seems to be less potent in modulating cellular cytotoxicity. These findings support the concept that gastrointestinal peptides can play a role in the regulation of cellular cytotoxicity against tumor cells, and, as mentioned earlier, palatability of food is a major stimulant of the secretion of these peptides. This should help the elderly who are more prone to malignancies. Indeed, taste
and smell losses in the elderly can reduce appetite and lead to inadequate dietary intake. Although these chemosensory deficits are generally not reversible, sensory interventions including intensification of taste and odor can compensate for perceptual losses. One method for “treatment” of chemosensory losses involves sensory enhancement of foods with flavors and monosodium glutamate (MSG). Amplification of flavor and taste can improve food palatability and acceptance, increase salivary flow and immunity, and reduce oral complaints in both sick and healthy elderly. Studies, conducted by S.S. Schiffman , show the effects of sensory enhancementwith flavors and/or MSG on food intake, satisfaction, immunityand salivation in the elderly. The results of these studies indicatethat amplification of taste and smell can improve food palatabilityand acceptance, improve lymphocyte counts, increase salivaryflow and increase secretion rate of salivary immunoglobulinA (sIgA). Eating flavor-enhancedfoods also led to improvement in one anthropometric measure(grip strength). In another study, the elderly residents ate flavor-enhancedfoods for 3 wk and the identical foods in unenhanced form foranother 3 wk. Half of the subjects received enhanced food firstand unenhanced food second; for the other half, the order wasreversed. Six flavors were utilized throughout the study: roastbeef, ham, natural bacon, prime beef, maple and cheese. These flavorswere primarily odors; they were virtually tasteless and containedno NaCl or sweeteners.The immune and functional improvements (i.e., increased T andB cell counts and improved grip strength) found in the studyoccurred as a result of intensifying the flavor of some butnot all foods at a meal. Subjects ate more of the flavor-enhancedfoods and less of the unenhanced foods. As a consequence, theyconsumed the same macro- and micronutrients on the enhancedand unenhanced arms of the study. That is, they consumed thesame nutrients on both arms of the study; the only differencebetween the foods consumed during the enhanced and unenhancedarms was the flavor level experienced by the subjects. Yet, flavorenhancement improved immunity and grip strength! Similar results werefound in an additional study that used MSG and flavors to intensifyboth taste and smell simultaneously.The improved immune status produced by flavor enhancement mayresult from one or more of the following four possibilities.First, direct neural-immune connections exist between thoseparts of the brain that subserve olfaction and the immune system. Thus olfactory stimulation could boostimmune function directly via these connections. Second, theelevated flavor levels may lead to greater release of digestiveenzymes and produce better absorption of micronutrients. Third,there may be phytochemicals in the flavors that directly improveimmunocompetence due to their biochemical actions. Fourth, flavorenhancement may improve mood, leading to reduced circulatingcortisol: cortisol, the stress hormone, is known to suppress the immune status.The results of one experiment showed that applicationof sugar (taste alone) and flavor (taste and odor combined)to the tongue induced significantly higher secretion rates ofsIgA than the application of water in both young and elderlysubjects. In addition, flavor application produced significantlyhigher absolute concentrations of sIgA than sugar applicationalone. Secretion rates of sIgA in young persons were significantlyhigher than those in elderly persons. In another study, theincrease in sIgA secretion rate for the elderly subjects at30 and 60 min for each food with MSG was greater than that observedwhen the same food was consumed without MSG. The short-termincreases in sIgA secretion rates in these two experiments maybe due to the following: 1) the elevated salivary flow causedby reflex secretion of saliva containing sIgA, and 2) possibleneural-immune interactions that inducedelevated absolute concentrations of sIgA (in the flavor conditionin the first experiment). Schiffman also tested flavor preferences in 13 patients who were undergoingor had recently completed chemotherapy (10 subjects) or radiotherapy(3 subjects) for breast cancer. In a single-blind study, patientswere given two samples of a food to taste and were asked whichone they preferred. For all items, the majority of cancer patientspreferred the flavor-enhanced food to the unenhanced food. None of the patients reported an aversion to the foodsthat were tested.During testing, several cancer patients indicated that the odors remindedthem of pleasant times in the past. Thus, flavor amplification mightpotentially reduce complaints about foods, not only because they improvesensory qualities, but because they trigger pleasant memories. Odorsignals are processed in the “limbic system” of the brain, whichalso processes emotions and memories;furthermore this portion of the brain interacts with the immunesystem, which may be advantageous forcancer patients. These observations and concepts have been confirmed by others [Mathey et al. 2001]: adding flavor enhancers to the cooked meals was an effective way to improve dietary intake and body weight in elderly nursing home residents, in the Netherlands. With the right choice of condiments, seasonings or sauces, ordinary food can go from “blah” to “ahh!” –with a boost in nutritional value. Condiments give a chance to be adventurous and to taste other cuisines without leaving home; tandoori sauce, barbeque sauce or spicy brown mustard takes your meal to India, Texas or Germany. The condiments we choose are only limited by our imagination [Fitch-Hilgenberg 2007]. Indeed, nutrition –and pleasure of eating- is a major factor influencing immunity in the elderly [Lesourd 2004]; in seniors, decreased T-cell, B-cell subsets and functions, and innate immunity are all strongly related to protein nutritional and micronutrient status. Stress after stress, and anhedonia at meals, pushes the elderly to frailty.
Herbs and spices have a traditional history of use, with strong roles in cultural heritage, and in the appreciation of food and its links to health. Demonstrating the benefits of foods by scientific means remains a challenge, particularly when compared with standards applied for assessing pharmaceutical agents. Pharmaceuticals are small-molecular-weight compounds consumed in a purified and concentrated form. Food is eaten in combinations, in relatively large, unmeasured quantities under highly socialized conditions. The real challenge lies not in proving whether foods, such as herbs and spices, have health benefits, but in defining what these benefits are and developing the methods to expose them by scientific means. The place of herbs and spices in the diet needs to be considered in reviewing health benefits. This includes definitions of the food category and the way in which benefits might be viewed, and therefore researched. Research may focus on identifying bioactive substances in herbs and spices, or, in tune with reality, on their properties as a whole food, and/or be set in the context of a dietary cuisine. The antioxidant properties of herbs and spices are of particular interest in view of the impact of oxidative modification of low-density lipoprotein cholesterol in the development of atherosclerosis. There is level III-3 evidence (National Health and Medical Research Council [NHMRC] levels of evidence) that consuming a half to one clove of garlic (or equivalent) daily may have a cholesterol-lowering effect of up to 9%. There is level III-1 evidence that 7.2 g of aged garlic extract has been associated with anti-clotting (in vivo studies), as well as modest reductions in blood pressure (an approximate 5.5% decrease in systolic blood pressure). A range of bioactive compounds in herbs and spices have been studied for anti-carcinogenic properties in animals, but the challenge lies in integrating this knowledge to ascertain whether any effects can be observed in humans, and within defined cuisines. Research on the effects of herbs and spices on mental health should distinguish between cognitive decline associated with aging and the acute effects of psychological and cognitive function. There is level I and II evidence for the effect of some herbal supplements on psychological and cognitive function. There is very limited scientific evidence for the effects of herbs and spices on type 2 diabetes mellitus, with the best evidence being available for the effect of ginseng on glycemia, albeit based on four studies. More research is required, particularly examining the effects of chronic consumption patterns. With increasing interest in alternatives to non-steroidal anti-inflammatory agents in the management of chronic inflammation, research is emerging on the use of food extracts. There is level II evidence for the use of ginger in ameliorating arthritic knee pain; however, the improvement is modest and the efficacy of ginger treatment is ranked below that of ibuprofen. In addition to delivering antioxidant and other properties, herbs and spices can be used in recipes to partially or wholly replace less desirable ingredients such as salt, sugar and added saturated fat in, for example, marinades and dressings, stir-fry dishes, casseroles, soups, curries and Mediterranean-style cooking. Vegetable dishes and vegetarian options may be more appetizing when prepared with herbs and spices. As several metabolic diseases and age-related degenerative disorders are closely associated with oxidative processes in the body, the use of herbs and spices as a source of antioxidants to combat oxidation warrants further interest; and as with most foods, the real benefits of including them in the diet are likely to emerge with a better understanding of the attributes of health that are best supported by food, and in methodological developments addressing the evidence base for their effects. These developments are well underway through evidence-based frameworks for substantiating health claims related to foods. With time, we can expect to see a greater body of scientific evidence supporting the benefits of herbs and spices in the overall maintenance of health and protection from disease [Tapsell et al. 2006].
Sugars and fat play a unique role in the human diet [Drewnowski 1995]. The selective choice of sugars and fat as chief energy sources seems to be influenced less by the body’s energy needs than by the sensory appeal of sweet and fat-rich foods. This appeal typically holds not only across individuals, but also across cultures. Although many behavioral, social, and cultural factors play major roles in diet selection, people respond primarily to the sensory qualities of food (“We eat only what we like”). Some clinical studies have reported that individual food choices, and therefore the macronutrient composition of the diet, are influenced directly by the central nervous system. However, broader population-based studies point to the central role of taste in determining food selection. Survey studies have shown that the global consumption of sugars and fat is further determined by such variables as income, socioeconomic status, and the availability of sugars and fat in the food supply. Nutrition intervention strategies aimed at promoting dietary change in communities ought therefore to consider not only physical health, but also, and most importantly, the sensory pleasure response, and a wide range of demographic, economic, and sociocultural variables.
An increasing proportion of food consumption appears to be driven by pleasure, not just by the need for calories. The food environment may be creating an appetitive counterpart to the psychological effects of other hedonically-driven activities such as drug use and compulsive gambling. Homeostatic (i.e., eating because of physical need) and hedonic (eating for pleasure in the absence of need) eating motives overlap but are nonetheless separable. Some individuals may experience frequent thoughts, feelings and urges about food in the absence of any short-or long-term energy deficit. Delicious food can itself create powerful motives to keep eating it, much like more traditional addictive substances. In environments where such foods are always available, such motives may continue to manifest themselves in food-related thoughts and urges even when we are away from food. The smell of freshly baked doughnuts can entice someone to stop at a bakery and eat the doughnut or the sight of a dessert can attract a person to eat even when physically full after dinner. Once such habits are firmly established, trying to change them may not be a matter of “just saying no;” rather, such discontinuation may produce withdrawal responses. Traditionally, it has been thought that food is a form of self-medication for stress or boredom, but we should look beyond psychological factors when studying the facts behind superfluous eating. For one, rather than viewing such eating as pure indulgence, eating for pleasure may have been an evolutionary adaptation that helped us survive periods of food scarcity in the distant past. Palatable foods may create powerful motivations to eat not only because their taste is rewarding but because their consumption prevents the anxiety or stress that would occur if they were not consumed. Most normal-weight restrained eaters are trying to control their food intake not to lose weight but to prevent overeating and weight gain. It is logical to expect that the combination of susceptibility toward overeating and conscious efforts to avoid overeating would result in more frequent instances of “hedonic hunger” [Lowe et al. 2007].
Palatable sweet ingestion produces a morphine-like analgesia in both rats and human infants. To determine whether palatable sweet ingesta induces antinociception in human adults, 60 Canadian university [Mercer et al. 1997] students (30 men, 30 women) were exposed to a pressure algometer both before and after consuming either a sweet soft drink, filtered tap water, or nothing (Experiment 1). Pain responsivity was assessed with four pain measures: threshold, tolerance, and visual analogue scale (VAS) ratings of intensity and unpleasantness. Results showed that women who consumed either soft drink or water reported increased pain tolerance and VAS ratings at post-treatment compared with those receiving nothing. However, differences between groups were not found for men. Moreover, compared to men, women reported lower pain thresholds and tolerances and rated the pain as more intense. In Experiment 2, 40 women consumed either nothing or foods that they rated previously as palatable (chocolate-chip cookies), unpalatable (black olives), or neutral (rice cakes). Women who consumed the palatable sweet food showed increased pain tolerance compared with those receiving the unpalatable food, the neutral food, or nothing. These data demonstrated that “palatability-induced antinociception” (PIA) occurs in human adults.
Recent studies have demonstrated what we suspected: the cannabinoids we make enhance sweet taste. Endocannabinoids act in the brain to increase appetite and modulate taste receptors on the tongue to increase response to sweets, with no effect on sour, salty, bitter or umami taste. They are also found in intestine & pancreas helping nutrient absorption, insulin secretion and energy metabolism, and demonstrate an opposite action to leptin [Yoshida et al. 2009].
Glucagon-like peptide-1 (GLP-1), released from gut endocrineL cells in response to glucose, regulates appetite, insulinsecretion, and gut motility. Glucose given orally, but notsystemically, induces GLP-1 secretion. Human duodenal L cells express sweet taste receptors, the tasteG protein gustducin, and several other taste transduction elements. The human L cell line NCI-H716 expresses -gustducin,taste receptors, and several other taste signaling elements.GLP-1 release from NCI-H716 cells was promoted by sugars andthe noncaloric sweetener sucralose, and blocked by the sweetreceptor antagonist lactisole or siRNA for -gustducin. L cells of the gut “taste” glucose through the same mechanismsused by taste cells of the tongue. Modulating GLP-1 secretionin gut “taste cells” may provide an important treatment forobesity, diabetes and abnormal gut motility [Jang et al. 2007].
But fat might not be that guilty; in fact fatty foods curb hunger! Feeding stimulates small-intestinal mucosal cells to produce the lipid messenger oleoyleethanolamide (OEA) which decreases meal frequency. Duodenal infusion of fat stimulates OEA mobilization in the proximal small intestine, whereas protein or carbohydrates don’t. Activation of small-intestinal OEA mobilization, enabled by uptake of dietary oleic acid, serves as molecular sensor linking fat ingestion to satiety [Schwartz et al. 2008].
Chocolate Beats Prozac®:
Although addictive behavior is generally associated with drug and alcohol abuse or compulsive sexual activity, chocolate may evoke similar psychopharmacologic and behavioral reactions in susceptible persons. A review of the literature [Bruinsma et al. 1999] on chocolate cravings indicates that the hedonic appeal of chocolate (fat, sugar, texture, and aroma) is likely to be a predominant factor in such cravings. Other characteristics of chocolate, however, may be equally as important contributors to the phenomena of chocolate cravings. Chocolate may be used by some as a form of self-medication for dietary deficiencies (e.g. magnesium) or to balance low levels of neurotransmitters involved in the regulation of mood, food intake, and compulsive behaviors (e.g. serotonin and dopamine). Chocolate cravings are often episodic and fluctuate with hormonal changes just before and during the menses, which suggests a hormonal link and confirms the assumed gender-specific nature of chocolate cravings. Chocolate contains several biologically active constituents (methylxanthines, biogenic amines, and cannabinoid-like fatty acids), all of which potentially cause abnormal behaviors and psychological sensations that parallel those of other addictive substances. Most likely, a combination of chocolate’s sensory characteristics, nutrient composition, and psychoactive ingredients, compounded with monthly hormonal fluctuations and mood swings among women, will ultimately form the model of chocolate cravings. Dietetics professionals must be aware that chocolate cravings are real. The psychopharmacologic and chemosensory (beneficial) effects of chocolate must be considered when formulating recommendations for overall healthful eating and for treatment of nutritionally related health issues.
A recent study included 11 volunteers who classified themselves as “chocolate desiring” and 11 other who were “chocolate indifferent”. In this controlled clinical study, each subject –all men- ate chocolate or placebo over a five day period while their blood and urine samples were extensively analyzed. The “chocolate lovers” had a hallmark metabolic profile that involved low levels of LDL-cholesterol (the “bad” one), and marginally elevated levels of albumin (beneficial). The chocolate lovers expressed this profile even when they ate no chocolate. The activity of the gut microflora in the chocolate lovers was also distinctly different from those in the chocolate indifferent group. Food preference, e.g. chocolate, might be programmed or imprinted into our metabolic system (nutrimetabonomic) in such a way that the body becomes attuned to a particular diet. This imprinting is independent of the ingested food, as chocolate consumption versus placebo had no direct effect [Rezzi et al. 2007].
Dark chocolate controlled anxiety, depression and stress, and restored health in a free living group [Martin et al. 2009]. The study explored the metabolic responses of free living subjects to a daily consumption of 40 g of dark chocolate for up to 14 days. A clinical trial was performed on a population of 30 human subjects, who were classified in low and high anxiety traits using validated psychological questionnaires. Biological fluids (urine and blood plasma) were collected during 3 test days at the beginning, midtime and at the end of a 2-week study. NMR and MS-based metabonomics were employed to study global changes in metabolism due to the chocolate consumption. Human subjects with higher anxiety trait showed a distinct metabolic profile indicative of a different energy homeostasis (lactate, citrate, succinate, trans-aconitate, urea, proline), hormonal metabolism (adrenaline, DOPA, 3-methoxy-tyrosine) and gut microbial activity (methylamines, p-cresol sulfate, hippurate). Dark chocolate reduced the urinary excretion of the stresshormone cortisol and catecholamines, and partially normalized stress-related differences in energy metabolism (glycine, citrate, trans-aconitate, proline, beta-alanine), and gut microbial activities (hippurate and p-cresol sulfate). These results provides strong evidence that a daily consumption of 40 g of dark chocolate during a period of 2 weeks is sufficient to modify the metabolism of free living and healthy human subjects, as per variation of both host and gut microbial metabolism.
Wine is Health, Medicine, Pleasure, and More:
Wine has been part of human culture for >6,000 years, serving dietary and socio-religious functions. It contains a range of polyphenols that have desirable biological properties; these are 5 times higher in wine than in fresh grapes; fermentation dissolves them into wine. Catechin and epicatechin peak at about 2 hours, and half-life is about 4 hours, suggesting that regular ingestion, with food, is good. Indeed, wine may confer protection against adverse effects of some foods [Renaud et al. 1998].
The list of activities of plant and wine flavonoids did not include effects on the central nervous system (CNS) up to 1990, when Paladini et al.  described the existence of natural anxiolytic flavonoids. The first of these was chrysin (5,7-dihydroxyflavone), followed by apigenin (5,7,4′-trihydroxyflavone) and flavone itself. Semisynthetic derivatives of flavone obtained by introducing halogens, nitro groups or both in its molecule, give rise to high affinity ligands for the benzodiazepine receptor, active in vivo; 6,3′-dinitroflavone, for example, is an anxiolytic drug 30 times more potent than diazepam (Valium®).
Regular intake of red wine brings a better sex life to women: regular moderate intake of red wine is associated with higher Female Sexual Function Index (FSFI), vaginal lubrication and overall sexual function when compared to the teetotaler. It suggests a relationship between red wine consumption and better sexuality in women aged 18-50 [Mondaini et al. 2009].
But wine, or wine-derived molecules, is/are not primarily tranquilizer(s). Wine is first-and-above all Pleasure. As Robert M Parker Jr. says it [Langewiesche 2000] “Part of life is to live it and enjoy it, and seize the moment that you find particularly pleasing. ’Fettuccine Alfredo is dangerous for your health. Kung pao chicken will destroy your life’. Holy shit, the first week it’s one of the classics of Italian cooking, the next week it’s one of the staples of Chinese cooking! These are the people who do studies that your carry-out Chinese meals are saturated in fat…. I’d just like to meet them! I mean, what do they do for pleasure? Pleasure is defined by dining, and let us get rid of the Pleasure Police (CSPI) whose business is “the taboo of the week”.
But the enjoyment of wine is influenced by the shape of the wine glass. This is not only the demonstration done by Georg Riedel, but the result of a study [Huttenbrink et al. 2001] conducted on 99 healthy volunteers: egg-shaped glasses, compared to “tulip” or “beaker” glasses appear to deliver higher intensity and higher complexity of wine bouquet.
And that’s why wine lovers learn to taste. We know that the effort we put into understanding and appreciating wine–as opposed to simply enjoying it (or its psychotropic effects)–pays big dividends. Really tasting wine adds an extra dimension to the basic daily routines of eating and drinking. It turns obligation into pleasure, a daily necessity into a celebration of life [Matthews 1996].
Moderate, a.k.a. Pleasurable, Exercise vs. Exhaustive Exercise:
Acute exercise is followed by a mobilization of white blood cells, mainly induced by increased levels of catecholamines and cortisol, both stress-related. NK-cells react the most intensively; they can increase fivefold after intensive exercise. Additionally a weak acute-phase reaction occurs. Most of the time, these changes normalize over twenty-four hours. The humoral immune system may react differently from the pre-exercise levels up to seventy-two hours. Repeated physical exercise, which is typical in sports, is followed only by small changes of immunologic parameters under conditions of rest. Epidemiological studies give clues that the rate of upper respiratory tract infections in athletes can be described by a j-shaped curve. Moderately active subjects have the lowest rate of infection. The influence of exercise on health creates mainly functional changes. But after eccentric exercise immunological cells can be seen in the muscle, as they try to remove destructed tissue [Baum et al. 1997]. A group at the University of Paderborn, Germany [Baum et al. 1997a] investigated whether moderate or exhaustive endurance exercise influences cytokine levels in whole-blood culture supernatants after stimulation. Moderate exercise influenced the γ-IFN production (PHA-stimulated), which increased significantly from 974 (391) pg/ml before exercise to 1450 (498) pg/ml 24 h later. Thirty minutes after exhaustive exercise the γ-IFN level in the supernatants (SEB-stimulated) was significantly decreased (from 14470 (11840) pg/ml before exercise to 6000 (4950) pg/ml after exercise). The IL-1beta and TNF-alpha production per monocyte was also significantly reduced after exhaustive exercise.
After intense long-term exercise, the immune response is characterized by concomitant impairment of the cellular compartment, and increased inflammation. Thus low concentrations of lymphocytes, suppressed natural immunity, suppressed lymphocyte proliferation, and suppressed levels of secretory IgA in saliva are found simultaneously with high levels of circulating proinflammatory and anti-inflammatory cytokines. The underlying mechanisms are multifactorial and include neuroendocrinological (stress) and metabolic factors. The clinical consequences of the exercise induced immune changes have not formally been identified, but the exercise effect on lymphocyte dynamics and immune function may be linked to the exercise effects on resistance to infections [Gani et al. 2003], frequency of allergies and malignancies, and the cytokine response may be linked to muscle damage or muscle cell growth. Moderate, pleasurable exercise across the life span seems to increase resistance to upper respiratory tract infections, whereas repeated strenuous exercise suppresses immune function, with potential dire consequences [Pedersen et al. 2000].
A positive attitude and an active coping style may be very important to keep a healthy immune response. This is of particular relevance for HIV+ subjects. A study was conducted at the University of Miami, Florida [Goodkin et al. 1992] to examine the hypothesis that a psychosocial model was associated with natural killer cell cytotoxicity (NKCC) in HIV-1 infection. A sample of 62 HIV-1 seropositive homosexual men at CDC stages II and III were given a psychosocial battery assessing life stressors, social support, and coping style. Active coping style was directly and positively associated with NKCC, and trends toward a negative relationship of life stressors and a buffering effect of social support on lives stressors were also observed. The results suggest that (1) control variables should be included with psychosocial models and that (2) psychosocial factors, especially active coping, may have a deterrent effect on loss of NK cell function. Active coping style may merit a specific focus in future research of life stressors and the immune system.
Hence, can guilt make you sick? To answer this question, G. Lowe et al.  conducted a study: before producing saliva samples for sIgA assay, 30 subjects listed their pleasurable activities and rated them in terms of pleasure and guilt. Guess what: levels of sIgA were higher in those subjects with high ratios of pleasure-guilt scores!
But exercise is very beneficial to obese people; 58 sedentary obese, males and females, participated in a 12-week aerobic exercise intervention. Despite attaining a lower-than-predicted weight reduction, these individuals experienced an acute exercise-induced increase in positive mood. Exercise should be encouraged -and the emphasis on stressful weight loss reduced [King et al. 2009].
(More) Sex is Good (Exercise):
I once caressed the idea of using sex as a substitute to gym, and an interesting approach to weight loss.
The sexual response is a form of exercise that has strong biological and evolutionary components. Few studies have focused upon sexual behavior as exercise. There are parallels between the orgasmic response and exercise. Physiological bases of the sexual response help to explain individual differences in sexual behavior and the well being that often accompanies states of passionate love, addiction and exercise. Studies suggest that sexual activity is associated with well being and longevity, yet many health and exercise professionals fail to take account of sexual activity in advancing exercise programs and executing studies; the so-called Ostrich Effect persists. Investigators need to separate the passionate love stage of relationships that are biologically based and last 3 to 4 years from the later stages of long term committed partnerships in which sexual activity continues as a form of exercise, competence expression and fun [Butt 1990]. Besides, people who have sex once or twice weekly have higher levels of sIgA than people who have sex <1/week, or never al all. People who perform sex >3 times/week have low levels of sIgA –the latter may be related to stress [Charnetski et al. 1999]. And sexual pleasure controls pain: in 2 studies with 10 women each, vaginal self-stimulation significantly increased the threshold to detect and tolerate painful finger compression, but did not significantly affect the threshold to detect innocuous tactile stimulation. In one study, 6 of the women perceived the vaginal stimulation as producing pleasure. During that condition, the pain tolerance threshold increased significantly by 36.8% and the pain detection threshold increased significantly by 53%. A second study utilized other types of stimuli. Vaginal self-stimulation perceived as pressure significantly increased the pain tolerance threshold by 40.3% and the pain detection threshold by 47.4%. In the second study, when the vaginal stimulation was self-applied in a manner that produced orgasm, the pain tolerance threshold and pain detection threshold increased significantly by 74.6% and 106.7% respectively, while the tactile threshold remained unaffected. A variety of control conditions, including various types of distraction, did not significantly elevate pain or tactile thresholds. B. Whipple and B.R. Komisaruk  concluded that in women, vaginal self-stimulation decreases pain sensitivity, but does not affect tactile sensitivity. This effect is apparently not due to painful or non-painful distraction.
Lesbians watching sexually stimulating videos had an increase in γ-IFN production paralleling the number of orgasms [Halpern 1996]. The rise in endorphin rate is prominently associated with orgasm(s), and useful enzymes (e.g. depolymerases) appear in the vaginal secretions when there is an orgasm [Nicoli et al. 1995].
Does semen have antidepressant properties? Ney  hypothesized that semen may have an effect on mood in women. Many of the compounds present in human semen, e.g. testosterone [Benziger et al. 1983], are absorbed through the vaginal epithelium, and testosterone is absorbed more quickly that way than through the skin [Wester et al. 1980]. Gordon G. Gallup Jr.et al.  demonstrated that the level of depressive symptoms among sexually active female college students (SUNY Albany) is related to the consistency of condom use. Females who had sex without condoms, and therefore would be more likely to have semen in their reproductive tract, evidenced fewer depressive symptoms. Consistent with the hypothesis that there may be something about semen that antagonizes depression, females who were having sex without condoms also showed lower depression scores than those who were abstaining from sex altogether. There was no difference in the (increased) depression scores between condom users and abstainers, demonstrating that it is not sexual activity per se that antagonizes depression. It would be interesting to investigate the possible antidepressant effects of oral ingestion of semen, or semen applied through anal intercourse (or both) among both heterosexual couples as well as homosexual males [Nicoli et al. 1995].
In older men, in order to prevent erectile dysfunction, regular sexual activity is recommended, as summarized in the conclusion of this extensive Finnish study: “Regular intercourse protects (older) men from the development of erectile dysfunction. This may have an impact on general health and quality of life. Doctors should support patients’ sexual activity” [Koskimaki et al. 2008].
Love is more than sex. B.R. Komisaruk and B. Whipple  define “love” as one’s having stimulation that one desires. The nature of the stimulation can range on a continuum from the most abstract cognitive, to the most direct sensory, forms. Thus, this definition of love encompasses having an emotional bond with a person for whom one yearns, as well as having sensory stimulation that one desires. They propose a neural mechanism by which deprivation of love may generate endogenous, compensatory sensory stimulation that manifests itself as psychosomatic illness. In addition, they also propose a neuroendocrine mechanism underlying sexual response and orgasm. The latter includes vaginocervical sensory pathways to the brain that can produce analgesia, release ocytocin, and/or bypass the spinal cord via the vagus nerve. They present evidence of the existence of non-genital orgasms, which suggests that genital orgasm is a special case of a more pervasive orgasmic process. The better our understanding of love, the greater is our respect for the significance and potency of its role in mental and physical health.
Pleasure Pathways and Possible Addiction:
The reward/reinforcement circuitry of the mammalian brain consists of synaptically interconnected neurons associated with the medial forebrain bundle, linking the ventral tegmental area, nucleus accumbens, and ventral pallidum. Electrical stimulation of this circuit supports intense self-stimulation in animals and, in humans, produces intense pleasure or euphoria. This circuit is strongly implicated in the neural substrates of drug addiction and in such addiction-related phenomena as withdrawal dysphoria and craving. But this circuit is also implicated in the pleasures produced by natural rewards (e.g., food, sex). Cannabinoids are euphorigenic in humans and have addictive liability in vulnerable persons, but were long considered “anomalous” drugs of abuse, lacking pharmacological interaction with these brain reward substrates. It is now clear, however, that cannabinoids activate these brain substrates and influence reward-related behaviors [Gardner et al. 1998].
Tobacco is worse than anthrax in the social psyche of the healthists. However, a recent Swedish study [Hjern et al. 2001] confirms that the herb of Jean Nicot can reduce the allergic burden in both children and adults. The method was a cross-sectional study of present and former smoking habits in relation to atopic disorders from data on 6909 young and middle-aged adults (16-49 years) and their 4472 children (3-15 years) from the Swedish Survey of Living Conditions in 1996-97. The authors observed that the prevalence of allergic asthma and allergic rhino-conjunctivitis decreased, in a dose-response manner (P = 0.03 and P = 0.004, respectively), with increasing exposure to tobacco smoke in the adult study population. This pattern was little changed when potential confounders (sex, age, education, domicile, country of birth) were entered into a multivariate analysis: the adjusted odds ratio (OR) for allergic rhino-conjunctivitis was 0.5 (0.4-0.7) for those who smoked at least 20 cigarettes a day and OR 0.7 (0.6-0.9) for those smoking 10-19 cigarettes, compared with those who reported that they never had smoked Former smokers had a tendency for a slightly lower risk: OR 0.9 (0.8-1.0). In a multivariate analysis, children of mothers who smoked at least 15 cigarettes a day tended to have lower odds for suffering from allergic rhino-conjunctivitis, allergic asthma, atopic eczema and food allergy, compared to children of mothers who had never smoked (ORs 0.6-0.7). Children of fathers who had smoked at least 15 cigarettes a day had a similar tendency (ORs 0.7-0.9). This study demonstrates an association between current exposure to tobacco smoke and a low risk for atopic disorders in smokers themselves and a similar tendency in their children. Smoking habits and atopic disorder in parents should not be considered independent variables in epidemiological studies of the connection between exposure to tobacco smoke and atopy in children.
College students were exposed to: either 30’ of tone/click, or 30’ of silence, or 30’ of Muzak, or 30’ of radio broadcast (rap) [Charnetski et al. 1998]. Saliva samples were collected before/after each exposure. The increase of s-IgA was significant after Muzak only!
An English group [Huckelbridge et al. 2000]examined whether an acute manipulation of mood to induce negative hedonic tone would be downregulatory, as in the chronic stress paradigm and further, whether induction of positive mood might have opposite effects. Two separate experiments were conducted. In the first, mood manipulation was by mental recall and in the second by music. For both sIgA concentration and sIgA secretion rate there was a significant elevation in response to the mood manipulation by recall regardless of hedonic tone. There was some evidence that for sIgA secretion rate the response was more pronounced for positive mood. Mood induction by music also resulted in significant elevations in sIgA concentration and secretion rate and responses were not distinguished by mood valence. None of the mood induction procedures was associated with changes in free cortisol. In these studies, the authors found no evidence that transient lowering of mood was downregulatory for salivary sIgA. The predominant finding was of sIgA mobilization.
Drum circles have been part of healing rituals in many cultures throughout the world since antiquity. Although drum circles are gaining increased interest as a complementary therapeutic strategy in the traditional medical arena, limited scientific data documenting biological benefits associated with percussion activities exist. The group of B.B. Bittman  attempted to determine the role of group-drumming music therapy as a composite activity with potential for alteration of stress-related hormones and enhancement of specific immunologic measures associated with natural killer cell activity and cell-mediated immunity at the Mind-Body Wellness Center, an outpatient medical facility in Meadville, PA. A total of 111 age- and sex-matched volunteer subjects (55 men and 56 women, with a mean age of 30.4 years) were recruited. Six preliminary supervised groups were studied using various control and experimental paradigms designed to separate drumming components for the ultimate determination of a single experimental model, including 2 control groups (resting and listening) as well as 4 group-drumming experimental models (basic, impact, shamanic, and composite). The composite drumming group using a music therapy protocol was selected based on preliminary statistical analysis, which demonstrated immune modulation in a direction opposite to that expected with the classical stress response. The final experimental design included the original composite drumming group plus 50 additional age- and sex-matched volunteer subjects who were randomly assigned to participate in group drumming or control sessions. Group drumming resulted in increased dehydroepiandrosterone-to-cortisol ratios, increased natural killer cell activity, and increased lymphokine-activated killer cell activity without alteration in plasma IL-2 or γ-IFN, or in the Beck Anxiety Inventory and the Beck Depression Inventory II. Drumming is a complex composite intervention with the potential to modulate specific neuroendocrine and neuroimmune parameters in a direction opposite to that expected with the classic stress response.
A group from McGill University [Blood et al. 2001], in Canada, used positron emission tomography (PET) to study neural mechanisms underlying intensely pleasant emotional responses to music. Cerebral blood flow changes were measured in response to subject-selected music that elicited the highly pleasurable experience of “shivers-down-the-spine” or “chills.” Subjective reports of chills were accompanied by changes in heart rate, electromyogram, and respiration. As intensity of these chills increased, cerebral blood flow increases and decreases were observed in brain regions thought to be involved in reward/motivation, emotion, and arousal, including ventral striatum, midbrain, amygdala, orbitofrontal cortex, and ventral medial prefrontal cortex. These brain structures are known to be active in response to other euphoria-inducing stimuli, such as food, sex, and drugs of abuse. This finding links music with biologically relevant, survival-related stimuli via their common recruitment of brain circuitry involved in pleasure and reward.
Music also helps restore vision in stroke patients. Patients who have lost part of their visual awareness following a stroke improve their ability to see when they are listening to music they like. They could identify colored shapes and red lights in their depleted side of vision while they were listening to their preferred music, compared with music they did not like or silence; they also experienced positive emotions. Similar effects may also be gained by making the patients happy in other ways [Soto et al. 2009].
In premature babies a.k.a. preemies music improved feeding; music, with a pacifier-activated lullaby system improved oral feeding among premature infants. Music helps control pain, as measured by heart rate and oxygen saturation, during circumcision [Hartling et al. 2009]. Some even prefer Mozart: premature babies from Tel-Aviv, Israel exposed to 30’Mozart music once daily gained weight faster, became stronger than those who weren’t. After hearing the music, the infants expended less energy. The repetitive melodies of Mozart’s music seem to affect the organizational centers of the brain cortex [Mandel et al. 2010]. (Rap music might have similar effects!!).
But it’s not only music that eases pain in children; watching funny videos does also deliver: 18 children (7-16 yrs) watched humorous videos before, during and after a standardized pain task (placing a hand in cold water). Pain appraisal and pain tolerance were recorded and examined in relation to humor indicators. The group demonstrated significantly greater pain tolerance while viewing funny videos [Stuber et al 2007].
What makes people happy in the 21st century?
A team of psychologists and economists reported in Science [Kahneman et al. 2004] what many of us know but don’t always admit: watching TV is a very enjoyable way to pass the time, but taking care of children is often as much fun as housework. The study asked 909 women living in Texas to use a novel questionnaire that probes the moment-to-moment emotions that constitute an ordinary day: the Day Reconstruction Method, with a diary listing everything from reading the newspaper in the morning to arguing with coworkers over lunch, or falling asleep with the socks on. Each activity was relived the next day and rated using 12 scales: how the subjects felt at the time, whether criticized, hassled, worried or warm, friendly and happy [Carey 2004]. In general the group had a slow start but soon experienced mild pleasure that increased through the day, with bouts of anger, anxiety or frustration. Sex, socializing with friends, and relaxing were rated most enjoyable; while commuting, housework, or facing a boss, were the least pleasurable. These women rated TV-watching high on the list, ahead of shopping and talking on the phone.
One of the most consistent findings in the study was how little difference money made (these data would probably look very different in a survey conducted in Hong Kong!). Job security, too, had little influence (this would be heresy in the US or France these days!). And, contrary to previous research, it was found that divorcees reported being slightly more cheerful during the day than did married women (great news for the Christian Right!).
Laughter remains good medicine in the 21st century. Beta-endorphins & HGH increased by 27% and 87% in subjects watching a humorous video. Cortisol, epinephrine and DOPAC were reduced by 39, 70 and 38% respectively. In diabetic patients, “mirthful laughter” increased HDL, lowered TNF-alpha, γ-IFN, IL-6 and hs-CRP [66% vs. 26%] (= reduced inflammation) [Berk et al. 2009]. These great results were sustained after one year!
Modern science-based interventions may revolutionize our use of “pleasure”. Deep brain stimulation [DBS] of the nucleus accumbens (the center for ‘pleasure’), with a portable (or even implantable) device was administered in 10 patients with severe long-term resistant [antidepressants, psychotherapy, ECT] depression. After 1 year of DBS, all patients showed improvement, including in anxiety. DBS did not impair the overall brain functioning. This was conducted in 2010 [Bewernik et al. 2010], but many more groups are testing this technology. Stay tuned!
When did Pleasure Start?
Michel Cabanac  answered this question. Gentle handling of mammals (rats, mice) and lizards (iguana), but not of frogs (Rana) and fish (Carassius), elevated the set-point for body temperature (i.e., produced an emotional fever) achieved only behaviorally in lizards. Heart rate, another detector of emotion in mammals, was also accelerated by gentle handling, from ca. 70 beats/min to ca. 110 beats/min in lizards. This tachycardia faded in about 10 min. The same handling did not significantly modify the frogs’ heart rates. The absence of emotional tachycardia in frogs and its presence in lizards (as well as in mammals), together with the emotional fever exhibited by mammals and reptiles, but not by frogs or fish, would suggest that emotion emerged in the evolutionary lineage between amphibians and reptiles. Such a conclusion would imply that reptiles possess consciousness with its characteristic affective dimension, pleasure. The role of sensory pleasure in decision-making was therefore verified in iguanas placed in a motivational conflict. To be able to reach a bait (lettuce), the iguanas had to leave a warm refuge, provided with standard food, and venture into a cold environment. The results showed that lettuce was not necessary to the iguanas and that they traded off the palatability of the bait against the disadvantage of the cold. Thus, the behavior of the iguanas was likely to be produced, as it is in humans, through the maximization of sensory pleasure. Altogether, these results may indicate that the first elements of mental experience emerged between amphibians and reptiles.
The Commercial Exploitation & Abuse of Pleasure:
The only natural thing in a diet cola is the water –and maybe some of the caramel. The active ingredient is phosphoric acid (pH: 2.8); it will dissolve a nail in <4 days. It washes calcium away from bones. [Wyshak et al. 1989; Wyshak et al. 1994; Mazariegos-Ramos et al. 1995; Guerrero-Romero et al. 1999; Tucker et al. 2006]To carry the concentrate, trucks must place the hazardous material card –just like explosives! Distributors use it to clean their trucks engines. But Coke and Pepsi have marketing and promotional budgets that exceed the GNP of most countries. With their collection of soft drinks, they are the major vectors for the perversion of taste, and subsequent addiction to the sweet taste.
Adam Drewnowski et al.  studied preferences and cravings for sweet high-fat foods observed among obese and bulimic patients, assuming that they may involve the endogenous opioid peptide system. The opioid antagonist naloxone, opioid agonist butorphanol, and saline placebo were administered by intravenous infusion to 14 female binge eaters and 12 normal-weight controls. Eight of the binge eaters were obese. During infusion, the subjects tasted 20 sugars/fat mixtures and were allowed to select and consume snack foods of varying sugar and fat content. Naloxone reduced taste preferences relative to baseline in both binge eaters and controls. Total caloric intake from snacks was significantly reduced by naloxone in binge eaters but not in controls. This reduction was most pronounced for sweet high-fat foods such as cookies or chocolate. No consistent effects on taste preferences or food intakes were observed with butorphanol. Hence, endogenous opioid peptides may well be involved in mediating taste responses and preferences for palatable foods, notably those rich in sugars and fat. Then, just remember these facts: ketchup at McDonald’s is much sweeter; it contains much heavier corn syrup. Only soft drinks are served. Vegetable oils “boil” the fries, and potatoes have a glycemic index that is much higher than sucrose. Based on several studies [Coluantoni et al. 2002; Avena et al. 2003], Bartley G. Hoebel, of Princeton University, could claim that Fast Food is “as addictive as heroin”!
Another major evidence came from Children’s Hospital, in Boston, MA [Ludwig et al. 2001]: D.S Ludwig and his group examined the relation between obesity in children –“the new American epidemic”- and the consumption of sugar/corn syrup-sweetened drinks. They enrolled 548 ethnically diverse schoolchildren (age 11.7 years, SD 0.8) from public schools in four Massachusetts communities, and studied them prospectively for 19 months from October 1995, to May 1997. They examined the association between baseline and change in consumption of sugar-sweetened drinks (the independent variables), and difference in measures of obesity, with linear and logistic regression analyses adjusted for potentially confounding variables and clustering of results within schools. They found that for each additional serving of sugar-sweetened drink consumed, both body mass index (BMI) (mean 0.24 kg/m2; 95% CI 0.10-0.39; p=0.03) and frequency of obesity (odds ratio 1.60; 95% CI 1.14-2.24; p=0.02) increased after adjustment for anthropometric, demographic, dietary, and lifestyle variables. Baseline consumption of sugar-sweetened drinks was also independently associated with change in BMI (mean 0.18 kg/m2 for each daily serving; 95% CI 0.09-0.27; p=0.02). Hence, consumption of sugar-sweetened drinks –and only that– is associated with obesity in children.
The evidence a contrario was demonstrated recently in the U.K. [James et al. 2004]: a targeted, school-based education program produced at 12 months a reduction in the number of soft drinks consumed, and was associated with a reduction in the number of overweight and obese children (-0.2% in the active group; +7.5% in the control group). Small changes in energy intake and output seem to have a major impact on obesity risk. The intervention in these six primary schools in southwest England was simple, involved no teacher training, and could easily be implemented by a health educator working in several schools. Schools can play an important role in obesity prevention in children.
Then, if sugar/corn syrup-sweetened, calorie-laden drinks are the culprits, why not switch to quasi-zero calorie sweeteners, e.g. aspartame? Again, the group of Marian Apfelbaum looked into the potential differences –and benefits- of aspartame drinks [Melchior et al. 1991]. Since it has been claimed that sucrose intake induces a rise in beta-endorphins, and in an attempt to discriminate between the sensorial and metabolic effects of sucrose intake in this process, the effects of two chocolate drinks were compared: one sweetened with 50 g of sucrose, the other with 80 mg of aspartame. Plasma beta-endorphin concentrations were more elevated after the aspartame drink than after sucrose or fasting, while insulin increased after drinking as much with aspartame as with sucrose. The authors suggest that the increase in beta-endorphin after aspartame-sweetened chocolate is related to insulin secretion in the absence of marked changes in blood glucose or with a direct effect of aspartame itself on beta-endorphin liberation. In other words, aspartame is potentially more addictive than sugar, and will increase the risk of obesity!
Another –growing- area of crass commercialism and depressing growth is the distribution of wine. One must not forget that the great appeal of wine is that it is a unique, distinctive, fascinating beverage and different every time one drinks it [Parker 2003]. But current industrial “winners” are fail-safe, technically correct, split-polished – in short, wines for fans of Velveeta® cheese, Muzak®, and frozen dinners.
Resting the Case for Pleasure:
“No sane man can afford to dispense with debilitating pleasures; no ascetic can be considered reliably sane. Hitler was the archetype of the abstentious man. When the other krauts saw him drink water in the Beer Hall they should have known he was not to be trusted!” [Liebling 1959].
Pleasure is not an “extra”, or bonus bringing a little more soul to certain of our acts; it is a fundamental part of animal life. It is just as difficult to define as spirit, but nonetheless man is very conscious of it; it intervenes in relation with “need” in the regulation of major homeostatic functions [Cabanac 1985].
Pleasure is a potent drive inducing forms of behavior adapted to physiological needs, especially in the case of temperature regulation and food-and-water intake. Subjects try to maximize their pleasure –just like rats! Sensory pleasure is an incentive to useful behavior, and maximization of pleasure the answer to physiological conflicts –a.k.a. stress [Krondl et al. 1986].
As Michel Cabanac reminds us: “Each of our decisions is ultimately driven by pleasure-seeking. Pleasure is the common currency that allows us to make any, and I mean any, decision in our lives. Any decision is made according to the trend to maximize pleasure”.
But we should be vigilant: bigots are everywhere. My late friend Bernard Zacharias, trombonist of the Sidney Bechet & Claude Luter jazz band, created an imaginary principality in the heart of France; its motto was Stultitia cinget.
Since I am (mostly) dealing with nutrition, remember that misinterpretation of reliable scientific findings is a major cause of abnormal nutrition behavior. Overreaction to fearmongering pseudo-health messages may precipitate such conditions as anorexia nervosa, or nutrient toxicity. Adverse food reactions, real or more often imagined, lead to restriction in food selection. Excessive austerity in food –and wine- use negates the pleasure of eating, a useful mechanism in food choice ensuring food diversity – and pleasurable health.
It is not by chance that most peoples toast as Salute/Salud/Santé….
PBMC Peripheral blood mononucleated (or mononuclear) cells
ACTH Adrenal corticotrophin hormone
LDL Low Density Lipoprotein
NMR Nuclear Magnetic Resonance
MS Mass Spectrometry
HIV Human Immunodeficiency Virus
NK Natural Killer Cell
HDL High Density Lipoprotein
IgA Immunoglobulin A
sIgA Secretory IgA
TNF Tumor Necrosis Factor
HGH Human Growth Hormone
DOPAC Dihydroxyphenylacetic Acid
SEB Staphylococcal Enterotoxin B
Hs-CRP High sensitivity C-Reactive Protein
GNP Gross National Product
CDC Centers for Disease Control
SUNY State University New York
Apfelbaum M. Diet after surgical operation. Presse Médicale. 1971;79:2027-32
Avena NM, Hoebel BG. A diet promoting sugar dependency causes behavioral cross-sensitization to a low dose of amphetamine. Neuroscience 2003;122:17-20
Baum M, Liesen H. Sports and the immune system. 1997;Orthopade 26:976-80
Baum M, Muller-Steinhardt M, Liesen H, Kirchner H. Moderate and exhaustive endurance exercise influences the interferon-gamma levels in whole-blood culture supernatants. Eur J Appl Physiol Occupat Physiol 1997;76:165-9
Benziger DP, Edelson J. Absorption from the vagina. Drug Metabol Rev 1983;14:137-168
Berk LS, Tan S. Laughter remains good medicine. 122nd Annual Meeting American Physiological Society, New Orleans, LA. 2009;April 18-22.
Bewernick BH, Hurlemann R, Matusch A et al. Nucleus accumbens deep brain stimulation decreases ratings of depression and anxiety in treatment-resistant depression. Biol Psychiatry 2010;67:110-116
Blood AJ, Zatorre RJ. Intensely pleasurable responses to music correlate with activity in brain regions implicated in reward and emotion. Proc Nat Acad Sci 2001;98:11818-23
Bray GA. Afferent signals regulating food intake. Proc Nutr Soc 2000;59:373-84
Brillat-Savarin JA. Physiologie du Goût ou Méditations de Gastronomie Transcendante Dédié aux Gastronomes parisiens par un Professeur. 1825. Paris:A. Sautelet. 128p
Bruinsma K, Taren DL. Chocolate: food or drug? J Am Diet Assoc 1999;99:1249-56
Butt DS. The sexual response as exercise. A brief review and theoretical proposal. Sports Med 1990;9:330-43
Cabanac M. Emotion and phylogeny. Jap J Physiol 1999;49:1-10
Cabanac M. Preferring for pleasure. American Journal Clinical Nutrition 1985;42:1151-5
Carey B. What makes people happy? TV, study says. NY Times Dec 3, 2004
Chalmers D. Facing up to the problem of consciousness. J Conscious Studies 1995;2:200-219
Charnetski CJ, Brennan FX Jr, Harrison JF. Effect of music and auditory stimuli on secretory immunoglobulin A (IgA). Percept Mot Skills 1998;87:1163-70
Charnetski CJ, Brennan FX Jr.. The effect of sexual behavior on immune system function. East Psychol Assoc Providence, RI. 1999, April 17
De Araujo IET, Rolls ET, Kringelbach ML, McGlone F, Phillips N. Taste-olfactory convergence and the representation of the pleasantness of flavour, in the human brain. Eur J Neurosci 2003;18:2059-2068
Drewnowski A, Krahn DD, Demitrack MA, Nairn K, Gosnell BA. Taste responses and preferences for sweet high-fat foods: evidence for opioid involvement. Physiol Behav 1992;51:371-9
Drewnowski A. Energy intake and sensory properties of food. Am J Clin Nutr 1995;62:1081S-1085S
Drewnowski A. Why do we like fat? J Am Diet Assoc 1997;97:S58-62
Epel ES, Blackburn EH, Lin J, Dhabbar FS, Adler NE, Morrow JD, Cawthon RM. Accelerated telomere shortening in response to life stress. Proc Natl Acad Sci USA. 10.1073/pnas.0407162101 [Dec 1, 2004]
Fitch-Hilgenberg M. Science Daily/U Arkansas Fayetteville 2007, Oct 27
Gallup Jr GG, Burch RL, Platek SM. Does semen have antidepressant properties? Arch Sexual Behav 2002;31:289-293
Gani F, Passalacqua G, Senna G, Mosca Frezet M. Sport, immune system and respiratory infections. Allerg Immunol (Paris) 2003;35:41-6
Gardner EL, Vorel SR. Cannabinoid transmission and reward-related events. Neurobiol Dis 1998;5:502-33
Goodkin K, Blaney NT, Feaster D, Fletcher MA, Baum MK, Mantero-Atienza E, Klimas NG, Millon C, Szapocznik J, Eisdorfer C. Active coping style is associated with natural killer cell cytotoxicity in asymptomatic HIV-1 seropositive homosexual men. J Psychosom Res 1992;36:635-50
Guerrero-Romero F, Rodriguez-Morán M, Evangelina R. Consumption of soft drinks with phosphoric acid as a risk factor for the development of hypocalcemia in postmenopausal women. J Clin Epidemiol 1999;52:1007-1010.
Halpern GM, Vruwink KG, Van de Water J, Keen CL, Gershwin ME. Influence of long-term yoghurt consumption in young adults. Int J Immunother. 1991;7:205-210
Halpern GM, Davis PA, Gershwin ME, Poilâne L. Etude comparative de la composition en acides gras de farines, produits de meunerie et boulangerie; broyage à la meule ou au cylindre. Médecine Hygiène. 1992;50:1006-1010
Halpern GM. Multiple orgasms are associated with increased γ-IFN production. Unpublished 1996
Hartling L, Shaik MS, Tjosvold L et al Music for medical indications in the neonatal period: a systematic review of randomised controlled trials Arch Dis Childh Fetal Neonatal 2009;94:F349-354
Hjern A, Hedberg A, Haglund B, Rosen M . Does tobacco smoke prevent atopic disorders? A study of two generations of Swedish residents. Clin Exper Allergy 2001;31:908-14
Hucklebridge F, Lambert S, Clow A, Warburton DM, Evans PD, Sherwood N. Modulation of secretory immunoglobulin A in saliva; response to manipulation of mood. Biol Psychol 2000;53:25-35
Huttenbrink KB, Schmidt C, Delwiche JF, Hummel T. The enjoyment of red wine is influenced by the shape of the wine glass. Laryngootorhinologie 2001;80:96-100
James J, Thomas P, Cavan D, Kerr D. Preventing childhood obesity by reducing consumption of carbonated drinks: cluster randomized controlled trial. BMJ 2004;328:1236-1243
Jang HJ, Kokrashvili Z, Theodorakis MJ, Carlson OD et al. Gut-expressed gustducin and taste receptors regulate secretion of glucagon-like peptide-1. PNAS 2007;104:15069-15074
Kahneman D, Krueger AB, Schkade DA, Schwarz N, Stone AA. A survey method for characterizing daily life experience: the day reconstruction method. Science 2004;306:1776-1780
Khan RM, Luk CH, Flinker A et al. Predicting odor pleasantness from odorant structure: pleasantness as a reflection of the physical world. J Neurosci 2007;27:10015-10023
King NA, Hopkins M, Caudwell P et al. Beneficial effects of exercise: shifting the focus from body weight to other markers of health. Br J Sports Med 2009;43:924-927.
Komisaruk BR, Whipple B. Love as sensory stimulation: physiological consequences of its deprivation and expression. Psychoneuroendocrinol 1998;23:927-44
Koskimäki J, Shiri R, Tammela T, Häkkinen J, Hakama M, Auvinen A. Regular intercourse protects against erectile dysfunction: Tampere aging male urologic study. Am J Med 2008;121:592-596
Kringelbach ML. Food for thought: hedonic experience beyond homeostasis in the human brain. Neuroscience 2004;126:807-819
Krondl M, Coleman P. Social and biocultural determinants of food selection. Progr Food Nutr Sci 1986;10:179-203
Langewiesche W. The million-dollar nose. The Atlantic2000;286:42-70
Leonard B. Stress, depression and the activation of the immune system. World J Biol Psychiatry 2000;1:17-25
Lesourd B. Nutrition: a major factor influencing immunity in the elderly. J Nutr Health Aging 2004;8:28-37
Liebling AJ. Between Meals. An Appetite for Paris. 1959.The Modern Library, NY. 182p
Lowe G, Greenman J, Lowe G. Pleasure, guilt and secretory immunoglobulin A. Psychol Rep 1999;85:339-40
Lowe MR, Butryn ML. Hedonic hunger: a new dimension of appetite? Physiol Behav 2007;91:432-439
Ludwig DS, Peterson KE, Gortmaker SL. Relation between consumption of sugar-sweetened drinks and childhood obesity: a prospective, observational analysis. Lancet 2001;357:505-8
Mandel D, Lubetzky R. Mozart therapy: a sonata a day keeps the doctor away. Tel Aviv U Med School http://sciencedaily.com/releases/2010/01/100107132551.htm
Mandel NI, Smeesters D et al. The sweet escape: Effects of mortality salience on consumption quantities for high- and low-self-esteem consumers. J Consumer Res 2008;08051417203817 DOI:10.1086/587626
Martin FP, Rezzi S, Peré-Trepat E et al. Metabolic effects of dark chocolate consumption on energy, gut microbiota, and stress-related metabolism in free-living subjects. J Proteome Res 2009;8:4799-4809
Mathey MFAM, Siebelink E, de Graaf C, Van Staveren WA. Flavor enhancement of food improves dietary intake and nutritional status of elderly nursing home residents. J Gerontol 2001;56A:M300-M305
Matthews T. The ABC’s of Wine Tasting. www.winespectator.com/Wines/Archives/Show-Article
Mazariegos-Ramos E, Geurrero-Romero F, Rodriguez-Morán M et al. Consumption of soft drinks with phosphoric acid as a risk factor for the development of hypocalcemia in children: a case-control study. J Pediatr 1995;126:940-942
Melchior JC, Rigaud D, Colas-Linhart N, Petiet A, Girard A, Apfelbaum M. Immunoreactive beta-endorphin increases after an aspartame chocolate drink in healthy human subjects. Physiol Behav 1991;50:941-4
Melchior JC, Rigaud D, Chayvialle
JA, Colas-Linhart N, Laforest MD, Petiet A, Comoy E, Apfelbaum M. Palatability of a meal influences release of beta-endorphin, and of potential regulators of food intake in healthy human subjects. Appetite 1994;22:233-44
Mercer ME, Holder MD. Antinociceptive effects of palatable sweet ingesta on human responsivity to pressure pain. Physiol Behav 1997;61:311-8
Mondaini N, Cai, T, Gontero P, Gavazzi A et al. Regular moderate intake of red wine is linked to a better women’s sexual health. J Sex Med 2009;6:2772-2777
Ney PG. The intravaginal absorption of male generated hormones and their positive effect on female behavior. Med Hypotheses 1986;20:221-231
Nicoli RM, Nicoli JM. Biochemistry of Eros. Contracept Fertil Sexual 1995;23:137-44
Oke SL, Tracey Kj. The inflammatory reflex and complementary and alternative medicine. Ann NY Acad Sci 2007 Sep 28 Epub 0:13930131
Olin KL, Simonoff M, Simonoff G, Halpern GM, Poilâne L. Evaluation of selenium content of French wheat flour and bread with PIXE technique. Trace Elem Electrol. 1994;11:121-124
Paladini AC, Marder M, Viola H, Wolfman C, Wasowski C, Medina JH. Flavonoids and the central nervous system: from forgotten factors to potent anxiolytic compounds. J Pharm Pharmacol 1999;51:519-26
Parker RM Jr. Introduction. Parker’s Wine Buying Guide. 5th Ed. 2003;Monkton, MD: Wine Advocate. 1703p
Pedersen BK, Toft AD. Effects of exercise on lymphocytes and cytokines. Br J Sports Med 2000;34:246-51
Remick AK, Pliner P, McLean KC. The relationship between restrained eating, pleasure associated with eating, and well-being re-visited. Eat Behav 2009;10:42-44
Renaud S, Gueguen R. The French paradox and wine drinking. Novartis Found Symp 1998;216:208-17; discussion 217-22, 152-8
Rezzi S, Ramadan Z, Martin FPJ, Fay LB et al. Human metabolic phenotypes link directly to specific dietary preferences in health individuals. J Proteome Res 2007;6:4469-4477
Rolls ET, Kringelbach ML, de Araujo IET. Different representations of pleasant and unpleasant odours in the human brain. Eur J Neurosci 2003;18:695-703
Rozin P, Ashmore M, Markwith M. Lay American conceptions of nutrition: dose insensitivity, categorical thinking, contagion, and the monotonic mind. Health Psychol 1996;15:438-447
Rozin P, Fischler C, Imada S, Sarubin A, Wrzeniewski A. Attitudes to food and the role of food in life in the U.S.A., Japan, Flemish Belgium and France: possible implications for the diet-health debate. Appetite1999;33:163-180
Schiffman SS. Intensification of sensory properties of foods for the elderly. J Nutr 2000;130:927S-30S
Schwartz GJ, Astarita G, Li X, Gaetani S, Campolongo P, Cuomo V, Piomelli D. The lipid messenger OEA links dietary fat intake to satiety. Cell Metab 2008;4:281-288
Soto D, Funes MJ, Guzman-Garcia A, Warbrick T, Humphreys GW. Pleasant music overcomes the loss of awareness in patients with visual neglect. PNAS 2009;DOI:10.1073/pnas.0811681106
Sternberg EM. Does stress make you sick and belief make you well? The science connecting body and mind. Ann N Y Acad Sci. 2000;917:1-3
Stuber M, Dunay Hilber S, Libman Mintzer L, Castaneda M, Glover D, Zeltzer L. Laughter, humor and pain perception in children: A pilot study. eCAM 2009;6:271-276
Tapsell LC, Hemphil T, Cobiac L et al. Health benefits of herbs and spices: the past, the present, the future. Med J Austr 2006;185(4 Suppl):S4-24.
Trapp CL, Chang CC, Halpern GM, Keen CL, Gershwin ME. The influence of chronic yogurt consumption in populations of young and elderly adults. Int J Immunother. 1993;9:53-64
Tu WM. Centrality and Commonality: An Essay on Confucian Religiousness. State University of New York Press, 1989
Tucker KL, Morita K, Qiao N et al. Colas, but no other carbonated beverages, are associated with low bone mineral density in older women. The Framingham Osteoporosis Study. Am J Clin Nutr 2006;84:936-942
van Tol EA, Verspaget HW, Pena AS, Jansen JB, Aparicio-Pages MN, Lamers CB. Modulatory effects of VIP and related peptides from the gastrointestinal tract on cell mediated cytotoxicity against tumour cells in vitro. Immunol Investig 1991;20:257-67
Vincent JD. Biology of pleasure. Presse Médicale 1994;23:1871-6
Wester RC, Noonan PK, Maibach H. Variations in percutaneous absorption of testosterone in the rhesus monkey due to anatomic site of application and frequency of application. Arch Dermatol Res 1980;267:229-235
Whipple B, Komisaruk BR. Elevation of pain threshold by vaginal stimulation in women. Pain 1985;21:357-67
Winkler MF. American Society of Parenteral and Enteral Nutrition Presidential Address: food for thought: it’s more than nutrition. JPEN 2007;31:334-340
Wyshak G, Frisch RE, Albright TE et al. Nonalcoholic carbonated beverage consumption and bone fractures among women former college athletes. J Orthop Res 1989;7:91-99.
Wyshak G, Frisch RE. Carbonated beverages, dietary calcium, the dietary calcium/phosphorus ratio, and bone fractures in girls and boys. J Adolesc Health 1994;15:210-215
Yoshida R, Ohkuri T, Jyotaki M et al. Endocannabinoids selectivelyenhance sweet taste. PNAS 2010;107:935-939.
Georges M. Halpern, MD, PhD
Distinguished Professor of Medicinal Sciences
The Hong Kong Polytechnic University
E-mail: [email protected]