Nutrition meets Genetics

One ongoing research is to develop food that can be matched to mine or your genotype to benefit our health and enhance normal physiological processes. This will lead to a personalized diet advice which may help to prevent monogenetic (=inherited disease controlled by a single pair of genes for example Cystic Fibrosis; Huntington’s Disease) and polygenetic diseases (=inherited and controlled by several genes at once for example cardiovascular diseases, high blood pressure, obesity, diabetes type II, Cancer, Osteoporosis and high cholesterol levels). It may sound science fiction right now cause until now all commercial companies ( e.g. Genelex, Sciona, TheDNADiet) who want to profit, just screen for 19 genes utilizing a multiplex technique that detects several SNPs ( Single Nucleotide Polymorphism, substitution of one nucleotide 1bp (point mutation) SNPs are located in regulatory sequences which belong to non coding region of the human genome. SNP could influence the transcription activity of other DNA regions. Most SNPs in that region have no effect.) simultaneously. This technique can be largely automated and is inexpensive. The 19 genes to be tested are coding for the following enzymes and proteins to mention a few MTHFR, PPARg, GSTM, VDR, IL-6, APOC 3. These are based on variations in the genes whereby they are not sufficient to give a personalized diet advice. The genes tested for SNP are involved in complex metabolic pathways. Current diet advices based on genetic tests don’t take complex metabolic pathways into account. After all there is lots of research needed.

The aim is to look for an approach that helps to solve the biochemical mechanism by which nutritional components like fatty acids influence health. One method is to use oligonucleotide microarrays to measure gene expression profiles of healthy individuals who regularly consume fish oil enriched with Ω-3 to individuals with no fish oil consumption. The results will show effects of fatty acids and other components in fish oil on gene expression, although for the greater amount of genes detected the exact function remains now unknown. What we benefit are genomic signatures that are associated with certain nutrients, diets or diseases. One can consider it as a fingerprint of a physiological or pathophysiological state or fingerprint of the phenotype.

In general the phenotype is determined by the genotype and external factors as lifestyle and nutritrition. Therefore it is possible that a certain genotype (polymorphism) leads in different people to different phenotypes.

Sometimes there is a clear relation between genotype, phenoype and effects of certain nutrients. Most times the relation between genotype, external factors and phenotype are complex. For example coronary heart disease is determined by the interaction of several genes and polymorphism of those genes including external factors. They are polygenetic complex diseases,also not all genetic factors are known to give a personalized diet advice.

In all there is a lot more to know about nutrition, genes and metabolic diseases.