Nutrigenomics
Authors: Rama Prashat G1 and Vinutha T2
1 Division of Genetics, IARI, New Delhi
2 Division of Biochemistry, IARI, New Delhi

Nutrigenomics is a branch of nutritional genomics which studies the interaction between nutrients and genes. Nutrients modulate the regulation and expression of coding genes of proteins, metabolism, cellular growth and differentiation. Nutrigenomics performs two functions, in explaining the functional interaction between the food bioactive components and the genome at molecular, cellular and systemic level and in revealing the effects of genic variation upon the diet and disease interaction.

Nutrigenomics study focuses in discovering the specific response of each individual to food items, so that the individualized dietetic recommendations can be developed. Nutrigenomics has been associated with the idea of personalized nutrition based on genotype. While nutrigenomics is aimed at developing an understanding of how the whole body responds to a food component through systems biology, the study of the effect of a single gene / single food compound interactions is known as nutrigenetics. Although these two terms are highly related, they need a fundamentally different approach in understanding gene-diet relation. But they share a common goal in improving the state of health and in preventing the appearance of nutritional diseases.

Diet-disease interaction

Understanding of the diseases’ appearance has been remarkably progressed since the successful completion of human genome sequence. Thousands of genes have been found to be associated with the development of some diseases, of which nearly 97 percent are single gene determining diseases. So by modifying the intake of some food items or nutrients, one can prevent diseases which are determined by single genes such as galactosemia and phenylketonuria. Diseases such as obesity, diabetes and cardio-vascular diseases appear as a result of the disfunctioning of more than one gene. Establishing some dietetic solutions in order to prevent these diseases help us in knowing the way in which a nutrient can influence a biologic system and the way in which the diet-interacts in modulating biological functions.

Food-gene interactions

Food contains gene expression regulators such as: nutrients, fatty acids, selenium, zinc and non-nutrients such as phytochemicals, metabolites of food components, isoflavones, etc., Nutrient-gene relations have been characterized by the following interaction types:

• The nutrients, mostly as a result of the interaction with a receptor, functions like transcription factors, by binding to the DNA, causing the alterations in gene expression.

• The nutrients can modify the DNA structure and hence altering the gene expression, which becomes chronic.

The nutrient-gene interactions can cause the changes in the genic transcription, mRNA translation, mRNA processing, mRNA determination and post translational modifications.

Examples
There are several nutrients which can modify the gene expression by behaving like transcription factors.

• Fatty acids interact with peroxisome proliferator-activated receptors, which modify gene expression by binding to the DNA.

• Vitamin A interacts with retinoic acid receptor and the resulting complex causes activation or inhibition by binding at a certain level of gene promotor region.

• Calcium and calcineurin interaction.

• Vitamin D and its receptor interaction.

• Zinc-transcriptional factor 1 interaction.

These examples of nutrients acts like a short term trigger and results in the modification of the transcription process and the effect generally disappears when the exposure to the specific nutrient has been stopped.

Conclusion

The integrated analysis of genetic, proteomic, metabolomic characteristics and of the complex interaction between the genome and food or nutrients should represent the evaluation basis of the nutritional status of a person. Nutrigenomics will promote an increased understanding of how nutrient influences metabolic pathways and homeostatic control, hence can be used to prevent the development of chronic diet related diseases such as obesity and diabetes. The aim of nutrigenomics is also to demonstrate the effect of bioactive food compounds on health and the effects of health foods on health, leading to the development of functional foods that will keep people healthy according to their individual needs. So it becomes important that there is a need for collective effort of the scientific community such as genetics, molecular biology, biochemistry, nutrition, bioinformatics, etc. Nutrition in particular nutrigenomics in this century represents an exciting and important field of research.

References:

1. Nicoleta Mitroi and Maria Mota (2008). Nutrigenomics/Nutrigenetics. Rom. J. Intern. 46(4): 295-304

2. Michelle Grayson (2010). Nutrigenomics. Nature. 468: S1


About Author / Additional Info:
Scientist in the Division of Genetics, Indian Agricultural Research Institute, New Delhi