Dietary responses

Simopoulos AP, Nestel PJ, eds. Genetic Variation and Dietary Response. World Review of Nutrition and Dietetics Vol. 80, Karger. Basel. 1997. 

Simopoulos, A.P. and Pavlou, K.N., Eds., Nutrition and Fitness 1 Diet, Genes, Physical Activity and Health, vol. 89, World Rev. Nutr. Diet., Karger, Basel, 2001. Simopoulos, A.P., Genetic variation and dietary response nutrigenetics/nutrigenom-... 

In this brief overview, diet-induced alterations in blood lipid profiles in three small animal models used in research on diet and human atherosclerosis have been discussed. When evaluating experimental data, it is essential to be aware of differences in the response of various animal models used for the study of the human disease. These considerations include a thorough characterization of the dietary response of the animal... 

Marshall MW, Smith BP, and Lehman RP. Dietary response of two genetically different lines of inbred rats Lipids in serum and liver. Proc. Soc. Exp. Biol. Med. 131 1271-1277 (1969). 

Smith AT, Kuznesof S, Richardson DP, and Seal CJ (2003) Behavioural, attitudinal and dietary responses to the consumption of wholegrain foods. Proceedings of the Nutrition Society 62 1-13. 

Salt Substitutes. As a result of concern about the relationship between dietary sodium and hypertension, some salt producers and food companies have developed salt substitutes or low sodium products. Mixtures of sodium chloride and potassium chloride, herbs and spices, as well as modified salt crystals of lower density are marketed in response to a limited consumer demand for reduced-sodium products. This amounts to about 2% of user salt purchases. 

Normally, dietary tyramine is broken down in the gastrointestinal tract by MAO and is not absorbed. In the presence of MAOI, however, all of its potent sympathomimetic actions are seen. Other side effects of MAOI include excessive CNS stimulation, orthostatic hypotension, weight gain, and in rare cases hepatotoxicity. Because the monoamine oxidase inhibitors exhibit greater toxicity, yet no greater therapeutic response than other, newer agents, clinical use has been markedly curtailed. The primary use for MAOIs is in the treatment of atypical depressions, eg, those associated with increased appetite, phobic anxiety, hypersomnolence, and fatigues, but not melancholia (2). 

Early applications of crystalline fructose focused on foods for special dietary applications, primarily calorie reduction and diabetes control. The latter application sought to capitalize on a signiftcandy lower serum glucose level and insulin response in subjects with noninsulin-dependent diabetes melUtus (21,22) and insulin-dependent diabetes (23). However, because fmctose is a nutritive sweetener and because dietary fmctose conversion to glucose in the hver requires insulin in the same way as dietary glucose or sucrose, recommendations for its use are the same as for other nutritive sugars (24). Review of the health effects of dietary fmctose is available (25). 

Three hormones regulate turnover of calcium in the body (22). 1,25-Dihydroxycholecalciferol is a steroid derivative made by the combined action of the skin, Hver, and kidneys, or furnished by dietary factors with vitamin D activity. The apparent action of this compound is to promote the transcription of genes for proteins that faciUtate transport of calcium and phosphate ions through the plasma membrane. Parathormone (PTH) is a polypeptide hormone secreted by the parathyroid gland, in response to a fall in extracellular Ca(Il). It acts on bones and kidneys in concert with 1,25-dihydroxycholecalciferol to stimulate resorption of bone and reabsorption of calcium from the glomerular filtrate. Calcitonin, the third hormone, is a polypeptide secreted by the thyroid gland in response to a rise in blood Ca(Il) concentration. Its production leads to an increase in bone deposition, increased loss of calcium and phosphate in the urine, and inhibition of the synthesis of 1,25-dihydroxycholecalciferol. 

An alkene, sometimes caJled an olefin, is a hydrocarbon that contains a carbon-carbon double bond. Alkenes occur abundantly in nature. Ethylene, for instance, is a plant hormone that induces ripening in fruit, and o-pinene is the major component of turpentine. Life itself would be impossible without such alkenes as /3-carotene, a compound that contains 11 double bonds. An orange pigment responsible for the color of carrots, /3-carotene is a valuable dietary source of vitamin A and is thought to offer some protection against certain types of cancer. 

One of the most prominent problems confronting the modem food processor is the prevention of rancidity. Rancidity affects not only the palatability of the food but the nutritive value as well—for example, oxidative spoilage of fats has been shown to be responsible for the partial destruction of the essential fatty acids (6) and of other dietary nutrients such as vitamins A (12) and E (9), and perhaps D (26) and certain members of the B complex (5, 29, SO). When one considers that nearly every food contains some fat and that this fat is subject to oxidative spoilage, the magnitude of the problem of rancidity is at once obvious. 

Niacin is used as adjunctive therapy for the treatment of very high serum triglyceride levels in patients who present a risk of pancreatitis (inflammation of the pancreas) and who do not experience an adequate response to dietary control. 

The expected outcomes for die patient may include a dierapeutic response to dierapy (lowered blood lipid levels), management of common adverse drug reactions, and an understanding of die dietary measures necessary to reduce lipid and lipoprotein levels. 

The methodological misstep most responsible for this interpretive chaos began with the inclusion of elements other than strontium and barium. Although it required extensive research to reveal the bone-diet connection for strontium, this was reduced, evidently for simplicity, and not altogether without validity, to the idea that plants are higher in strontium, than is meat, and that bones reflect this dietary difference. Then with Gilbert s thesis suggesting that zinc apparently also reflects this, the concept as transcribed to... 

Some animal studies indicate that dietary exposure to methyl parathion causes decreased humoral and cellular responses (Shtenberg and Dzhunusova 1968 Street and Sharma 1975). A more recent, well-designed animal study that included a battery of immuno/lymphoreticular end points showed few effects at the nonneurotoxic doses tested (Crittenden et al. 1998). No adequate studies are available in humans to assess the immunotoxic potential of methyl parathion. Therefore, studies measuring specific immunologic parameters in occupationally exposed populations are needed to provide useful information. Further studies are also needed to investigate the mechanism for methyl parathion-induced immunotoxicity since this information would help to identify special populations at risk for such effects. 

In addition to IL-10, TGF-(3 is a key cytokine in immune tolerance. It was investigated whether orally administered TGF-(3, such as TGF-(3 in human milk, retains and exerts its activity in the intestinal mucosa and can induce immune tolerance to dietary antigens. In a relevant mice model the oral administration of TGF-(3 increased activation and response in TGF-(3-related responsive elements and increased serum TGF-(3 levels [118]. BALB/c mice treated orally with OVA and TGF-(3 showed augmented... 

By definition, chylomicrons are found in chyle formed only by the lymphatic system draining the intestine. They are responsible for the transport of all dietary lipids into the circulation. Small quantities of VLDL... 

Dietary consumption of polyphenols is associated with a lower risk of degenerative diseases. In particular, protection of serum lipids from oxidation, which is a major step in the development of arteriosclerosis, has been demonstrated. More recently, new avenues have been explored in the capacity of polyphenols to interact with the expression of the human genetic potential. The understanding of the interaction between this heterogeneous class of compounds and cellular responses, due either to their ability to interplay in the cellular antioxidant network or directly to affect gene expression, has increased. 

Mortality rates from CVD are generally lower in Asian populations compared to Western populations (Knight and Eden, 1996). Although many dietary factors are known to play a protective role in CVD and it has been suggested that phytoestrogen content of Asian diets may be responsible for the cardioprotective effect. 

The current weight of evidence suggests that soy does have a beneficial effect on cardiovascular health however, the active component has yet to be identified. Studies have also demonstrated that dietary inclusion of phytoestrogen-rich foods can lower plasma cholesterol levels (Ridges et al., 2001). However, these data do not conclusively demonstrate that phytoesfrogens are responsible for the hypocholesterolemic effect, and it is possible that some other component in soy may be responsible (Erdman and Fordyce, 1989 Ling and Jones, 1995). 

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