Do our illnesses depend on nationality?

Julia Ratina, Really.Roo 

We already know that the appearance of many of our sores directly depends on how we eat. Moreover, this applies not only to each person specifically, but also to entire ethnic groups. But does their nationality affect the frequency of occurrence of certain diseases in different peoples? Scientists say that yes.

The latest discoveries of geneticists have already changed doctors' ideas about the causes of various ailments, helped to create new methods of diagnosis and treatment, but it turned out something else. It turns out that resistance or susceptibility to certain diseases can also be encoded in our genes. And in many ways it depends on the place of permanent residence of the people to which a person belongs.

The direction in science that studies this problem is called "ethnogenomics". Svetlana Borinskaya, a senior researcher at the Genome Analysis Laboratory of the Institute of General Genetics of the N. I. Vavilov Russian Academy of Medical Sciences, Candidate of Biological Sciences, tells about what it is and what diseases a particular ethnic group is prone to:

"We'll have to start with nutrition anyway. The traditional nutrition of the people directly depends on their lifestyle and the natural conditions of the area where they live permanently. For example, the Chinese and indigenous people of the North practically do not drink milk, which is considered unsuitable food for adults.

The fact is that these peoples do not produce or produce in very small quantities the enzyme "lactase", which is necessary for the normal assimilation of milk. Without this enzyme, even a glass of milk can cause digestive upset. For a long time, this condition was considered as a disease – hypolactasia.

However, studies have shown that people initially genetically had the cessation of lactase production in the body when they reached the age of five. So how did it happen that representatives of some nationalities still do this, while others calmly drink milk in adulthood? It turns out that the genes responsible for the duration of lactase production have mutated in the latter.

A similar mutation occurred in those areas of the globe where animal husbandry and dairy industry have been actively developing for many centuries. Most often it occurs in Danes, Dutch, Swedes, so more than 90% of the inhabitants of these countries can drink milk completely calmly. But in China, only 2-5% of adults have this ability.

Hypolactasia occurs in 30% of the Russian people. This is due to the fact that industrial milk production in Russia began later than in other European countries, and special dairy breeds of cows appeared only in the post-war period. Before that, milk was intended mainly for children or for the production of fermented milk products, which everyone can drink without harm to health, since milk sugar in them has already been processed into easily digestible substances.

There are diseases that haunt representatives of certain races. So, a mutation of the gene regulating salt metabolism, which occurs in people of the white race (in all European peoples and in us) leads to such a serious disease as cystic fibrosis – the gastrointestinal tract and respiratory system are affected. But the same disease in Jews or Bashkirs is caused by other mutations, each nation has its own.

So, if a disease is suspected, nationality helps to determine the most effective way of making a diagnosis — which mutation to look for in the patient, European or other. This is very important for early (especially prenatal) diagnosis, which allows you to start the necessary treatment in a timely manner or terminate pregnancy.

Another childhood hereditary disease is phenylketonuria (a metabolic disorder leading to mental retardation), for example, in Ireland and Scotland it occurs almost 2.5 times more often than in newborns in Russia or Europe. Phenylketonuria is cured by a special diet – the earlier it is prescribed, the better the result.

Celiac disease, in which the body is unable to digest cereals in Russia, occurs in one person out of two to three thousand, but, for example, in Ireland – in one out of a hundred. This is due to the fact that bread began to be sown here much later than in other European countries.

Finns and Russians are relatively resistant to alcohol. And residents of Southeast Asia get drunk quickly and even from small doses of alcohol can get severe poisoning. This is due to the fact that Asians have a common mutation that contributes to the rapid accumulation of acetaldehyde in the blood – a toxic product of the breakdown of ethyl alcohol. This is the reason for the unpleasant sensations that arise after taking large doses of alcohol.

If the carrier of the mutation still overcomes the troubles, then alcoholism will develop faster and it will be much harder to proceed due to severe chronic acetaldehyde poisoning. But even among alcoholics, carriers of the mutation drink less than those who do not have it.

Russians have 10 times lower accumulation of acetaldehyde in their blood after drinking alcoholic beverages due to genetic characteristics than Asian residents. Therefore, no mutations interfere with the development of alcoholism in our compatriots. In general, genes determine the habit of drinking by 40-60%, the rest depends on the conditions of upbringing, the social environment and the will of the person himself.

Here is another curious fact: the traditional diet of bushmen – hunter-gatherers living in South Africa, it turns out to fully comply with the recommendations of the World Health Organization on the overall balance of proteins, fats, carbohydrates, vitamins, trace elements and calories. The explanation is very simple: man and his ancestors for hundreds of thousands of years have adapted to this way of life, when dozens of animal species and more than a hundred wild plants served as a food source.

With the advent of agriculture and animal husbandry, the diversity of nutrition has sharply decreased, the composition of products has changed, and the development of industry has reduced physical activity. As a result, modern man has developed "diseases of civilization" – obesity, diabetes, cardiovascular diseases. Genes also play an important role here. For example, the apolipoprotein gene is involved in the regulation of cholesterol levels.

It exists in different variants: one (it is called "greedy" or "hoarding") effectively extracts cholesterol from food and accumulates it in the body, the other variant ("spender") gives a low cholesterol level. Hunter-gatherers (peoples living mainly in the tropical zone) with their traditional low-cholesterol diet, the "greedy" gene was beneficial, so here it occurs with a frequency of up to 40%.

But with a modern lifestyle, this feature (the accumulation of cholesterol in the body) becomes a risk factor for atherosclerosis and cardiovascular diseases. In developed countries, the "hoarding" gene (it occurs in European peoples with a frequency of 5-15%) is a risk factor for atherosclerosis. Other "greedy" genes that store previously deficient salt in the body threaten Europeans with hypertension.

As a result, African Americans, whose "greedy" genes are more common, are more susceptible to hypertension than Euro-Americans. And among the North Asian peoples, whose food was rich in fats, the transition to a European high-carbohydrate diet leads to the development of diabetes and other diseases. It is no accident that doctors with hypertension and atherosclerosis recommend physical activity, taking vitamins and trace elements, salt restriction, etc. – this is an artificial recreation of the conditions in which a person has lived for hundreds of thousands of years and to which he is biologically adapted.

But do not think that genes change only "for the worse", bringing problems with them. There are, for example, mutations that make some people immune to HIV infection. One of them is common in Europe, and other protective mutations with similar effects have been found in Asia and Africa. It is assumed that they spread due to the fact that in the past they could protect against other epidemics, and now they are useful to modern man.

The indigenous inhabitants of Tibet and the Andes have an increased hemoglobin content in the blood and increased pulmonary blood flow. So they adapted to life in high-altitude conditions. The indigenous peoples of the Arctic, who are engaged in fishing for sea animals, are distinguished by a special type of digestion, since with traditional nutrition, an adult consumed almost 2 kg of meat per day.

Moreover, such an amount of meat eaten did not lead to the development of atherosclerosis, since fish oil and marine animal fat, unlike fats of European cuisine, reduces, and does not increase the level of cholesterol in the blood.

The result of the action of drugs also depends on the genes. Recent studies have shown that up to a third of cases of unsuccessful treatment with even the most modern drugs can be caused by genetic causes. For example, almost 10% of white women suffer from endometriosis (gynecological disease). Most often, it is treated with the drug cycloferon, which does not help some patients because of their hereditary characteristics.

Of course, genetic differences do not imply the superiority of any one race or people over the rest. Every nation is adapted to the conditions in which it was formed. In addition, thanks to interethnic marriages and the continuous movement of people from one country to another, African, European and Asian genes are constantly mixed. So it is necessary to focus on the treatment of a particular disease, first of all, on the individual characteristics of a person.

Portal "Eternal youth" www.vechnayamolodost.ru20.10.2008