GENE:- NUTRIENT INTERACTIONS AND GENETIC SUSCEPTIBILITY

NUTRIENT INTERACTIONS

There is good evidence that nutrients and physical activity influence gene expression and have shaped the genome over several million years of human evolution.
Genes define opportunities for health and susceptibility to disease, while environmental factors determine which susceptible individuals will develop illness. In view of changing socioeconomic conditions in developing countries, such added stress may result in exposure of underlying genetic predisposition to chronic diseases. Gene--nutrient interactions also involve the environment. The dynamics of the relationships are becoming better understood but there is still a long way to go in this area, and also in other aspects, such as
disease prevention and control. Studies continue on the role of nutrients in gene expression; for example, researchers are currently trying to understand why omega-3 fatty acids suppress or decrease the mRNA of interleukin, which is elevated in atherosclerosis, arthritis and other autoimmune diseases, whereas the omega-6 fatty acids do not .
Studies on genetic variability to dietary response indicate that specific genotypes raise cholesterol levels more than others. The need for targeted diets for individuals and subgroups to prevent chronic diseases was acknowledged as being part of an overall approach to prevention at the population level.
However, the practical implications of this issue for public health policy have only begun to be addressed. For example, a recent study of the relationship between folate and cardiovascular disease revealed that a common single genemutation that reduces the activity of an enzyme involved in folate metabolism (MTHFR) is associated with a moderate (30%) increase in serum homocysteine and higher risk of both ischaemic heart disease and deep vein thrombosis .
Although humans have evolved being able to feed on a variety of foods and to adapt to them, certain genetic adaptations and limitations have occurred in relation to diet. Understanding the evolutionary aspects of diet and its composition might suggest a diet that would be consistent with the diet to which our genes were programmed to respond.
However, the early diet was presumably one which gave evolutionary advantage to reproduction in the early part of life, and so may be less indicative of guidance for healthy eating, in terms of lifelong health and prevention of chronic disease after reproduction has been achieved. Because there are genetic variations among individuals, changes in dietary patterns have a differential impact on a genetically heterogeneous population, although populations with a similar evolutionary background have more similar genotypes.
While targeted dietary advice for susceptible populations, subgroups or individuals is desirable, it is not feasible at present for the important chronic diseases considered in this report. Most are polygenic in nature and rapidly escalating rates suggest the importance of environmental change rather than change in genetic susceptibility.