DNA-Based Genetic Tests for Nutrition

With the Human Genome Project revealing our entire genetic structure, we began to better understand the importance of “genetic differences” in diseases, drug responses and personalized treatments. In recent years, the effect of genetic differences on nutrition has begun to gain importance. The aim of “nutrigenomics,” a new branch of science, is to develop individual nutritional recommendations and support personalized treatments.

Genetic Differences Affect Nutrition

The aim of tests conducted in this field is to examine the effect of certain genetic differences in individuals on nutrition. As is known, our cells are governed by the molecule called DNA. Through the genetic information it contains, DNA enables all vital processes to occur. The human genome (our entire genetic structure) consists of 3 billion nucleotides and 25 thousand genes. Genes are individual sections of DNA. These genes enable the production of functional molecules (proteins) in our bodies. The human genome is 99.5% shared. The small remaining part gives rise to differences.

Different types of variations of a gene are called polymorphism . Polymorphism occurs under certain circumstances. Between 4-5 million single nucleotide polymorphisms have been identified in the human genome. Some of these have been found to be associated with nutrition .

The aim of genetic tests in nutrigenomics is to compare these differences and offer the individual the most appropriate nutrition

For this purpose, many companies worldwide claim to have developed these tests and make them available commercially. These tests have not been approved by the American Food and Drug Administration (FDA), and some companies have been banned from selling these tests.

Epigenetic and genetic tests hold great promise for personalized medicine and nutrition in the near future. However, the number of genes with a proven relationship to nutrition so far is very small. These tests performed on a small number of genes do not reveal a person’s entire nutrigenomic structure. Indeed, individuals’ attitudes toward these genetic tests are not yet positive either.

A recently published study evaluated individuals’ views of DNA-based nutritional tests. Healthy men and women aged 20-35 were included in the double-blind, parallel-group, randomized controlled study. Some participants received DNA-based dietary advice, while others received general dietary advice.

At the beginning of the study and in months 3 and 12, participants’ views of these diets were assessed using questionnaires. According to the research results:

• The majority of participants stated at the end of the first 3 months that they believed in the relationship between diet and genetics.
• Nevertheless, 56 percent of participants stated that personalized nutrition should be managed by dietitians rather than based on genetic test results.
• At the same time, 88 percent of participants stated that personal genetic information should be obtained from university research laboratories rather than genetic testing companies.

Genetic tests can reveal people’s genetic structure and provide information about susceptibility to different diseases. They may also make it possible to prevent chronic diseases by enabling lifestyle changes. However, studies in this area are still conducted in the “laboratory” setting, and making major dietary changes based on these tests does not currently seem appropriate.