Шаргородская Анна Витальевна
Врач акушер-гинеколог, эндокринолог, специалист УЗ диагностики

Genetics and Nutrition

Is it true that genetic polymorphisms determine our dietary preferences?

It is believed that a person’s dietary preferences are largely determined by the characteristics of culture and upbringing. People who are trying to lose weight often hear the same advice – change their diet and their eating habits, or just eat less. The recommendations are sound, but is it so easy to change your eating habits if they are “predetermined” by genes?

Scientists from the Massachusetts General Hospital of Harvard Medical School performed genome-wide DNA analysis of 282,271 participants in the UK Biobank (n = 191,157) and Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium (n = 91,114) studies and found 26 genetic loci associated with preference for foods rich in protein, carbohydrates or fats.

This is one of the largest genome-wide studies of eating behavior and dietary factors to date, published in 2021 in the journal Nature Human Behavior. It confirmed the predetermining role of molecular genetic factors in the regulation of human eating behavior and dietary preferences.

Does this mean that it is written for a person to be fat or thin, sweet tooth or small?

To understand this, it is necessary to understand what gene polymorphism is, and what factors affect the expression of our genes, i.e. on which of them will work and which will remain “code”.

Gene polymorphisms are various inherited variations in the structure of DNA. Gene polymorphisms mainly determine the individual differences in any person’s qualities: eye or hair color, blood type, nose shape, etc. Some of the polymorphisms can be one of the factors of predisposition to diseases, for the development of which it is necessary to have such a hereditary predisposition plus the impact of unfavorable external conditions: the nature of the diet, the intake of toxins in the body, lack of vitamins, etc.

What is epigenetics?

In addition to heredity, everything that happens to us during life affects our DNA. The study of this is engaged in epigenetics – a branch of genetics that studies how our behavior and environment affect the work of our genes. Unlike genetic changes, epigenetic changes are reversible.

The genome is a “passport” in which all possible options for the development of an individual are recorded, but the program according to which the organism will develop depends largely on epigenetic factors. In other words, the work of genes is directly dependent on the environment.
And the first environment at the stage of the earliest development of any person is the mother’s organism. Genetic polymorphisms inherent in the prenatal stage largely depend on epigenetic factors affecting the expectant mother. In particular, studies have shown that exposure to harmful chemical factors on the mother’s body leads to changes in the epigenome, which contribute to the formation of a state of systemic inflammation with lifelong effects and consequences for the newborn. Therefore, it is so important what lifestyle a woman leads long before the planned pregnancy. What and how she eats, drinks, whether her body is exposed to harmful chemical and other factors.
An active study of the human microbiome has shown that the nature of the mother’s diet during pregnancy and breastfeeding has a direct impact on the formation of the intestinal microflora of the fetus and newborn, and the nutritional preferences of a person and his general health depend on the composition of the microbiome. Thus, the formation of healthy habits begins in utero.

Did you know that the activation of human taste buds begins as early as the 30th week of pregnancy?

During this period, changes in the chemical composition of the amniotic fluid caused by the mother’s diet can stimulate the taste buds of the fetus. This early activation appears as the first step in the development of gustatory sensory memory, which forms a preference for sweet, sour, or salty tastes, thereby influencing future newborn and baby food choices. Individual sensitivity and subsequent preference for sweet taste is also determined by the presence of specific receptors and genetic factors (tasirR gene polymorphism). The preference for sweet tastes is due to evolution. Sweet is carbohydrates, a source of fast energy, which means the shortest way to replenish the body’s energy reserves in conditions of limited resources. Modern man has unlimited access to sweet food and a low level of energy consumption in comparison with our ancestors, which leads to metabolic disorders and excessive accumulation of adipose tissue.

The development of individual preferences, the advantages of some food products over others is a complex process due to genetic aspects, motivational and behavioral factors. Genetics predetermines, but a person has the ability to choose what he should be, even without direct interference with the genetic code. It is possible to spoil the “good” genetics and prevent the activation of “bad” genes, but most importantly, the healthy habits and eating behavior of our children directly depend on the environment, which means, first of all, on the family!

Health to you and your children! And manage your genome correctly;)