Nutritional Genomics - Gene-Diet-Disease Interaction

Gene-Diet-Disease Interaction

97% of the genes known to be associated with human diseases result in monogenic diseases, i.e. a mutation in one gene is sufficient to cause the disease. Modifying the dietary intake can prevent some monogenic diseases. One example is phenylketonuria, a genetic disease characterized by a defective phenylalanine hydroxylase enzyme, which is normally responsible for the metabolism of phenylalanine to tyrosine. This results in the accumulation of phenylalanine and its breakdown products in the blood and the decrease in tyrosine, which increases the risk of neurological damage and mental retardation. Phenylalanine-restricted tyrosine-supplemented diets are a means to nutritionally treat this monogenic disease.

In contrast, many common diseases, such as obesity, cancer, diabetes, and cardiovascular diseases, are polygenic diseases, i.e. they arise from the dysfunction in a cascade of genes, and not from a single mutated gene. Dietary intervention to prevent the onset of such diseases is a complex and ambitious goal.

Recently, it was discovered that the health effects of food compounds are related mostly to specific interactions on molecular level, i.e. dietary constituents participate in the regulation of gene expression by modulating the activity of transcription factors, or through the secretion of hormones that in turn interfere with a transcription factor.