Decoding the genome will tell you which vitamins and minerals will improve your health
Given the rapid drop in prices for genome sequencing (one of the companies predicts a price reduction of up to $ 1,000 per individual genome within five years), the only reason for refusing this service may be the fear of learning any "bad news".
Scientists at the University of California, working under the guidance of Professor Jasper Rine, have found one "good news". They claim that genomic analysis allows to identify minor defects in genes, the effects of which can be neutralized with the help of elementary means, such as vitamins and mineral supplements.
There are a lot of genetic differences that reduce the effectiveness of various enzymes. To relieve the symptoms of a number of potentially dangerous metabolic disorders, doctors prescribe vitamins. However, such defects develop if there are two damaged copies or alleles of an enzyme in the genome. A large number of people live with one "bad" copy or two slightly altered copies of a gene. Such people may experience a slight decrease in enzyme activity and mild manifestations of metabolic disorder, which are easy to eliminate with the help of dietary supplements.
As part of the work, the authors tested the functioning of various variants of the human gene encoding the enzyme methylenetetrahydrofolate reductase (MTHFR), embedding them in yeast cells and evaluating the effectiveness of their work.
The enzyme under study, which requires folic acid (vitamin B9) to function, plays a key role in the synthesis of molecules necessary for the construction of nucleotides – the "building blocks" of DNA. Some anticancer drugs, such as methotrexate, block the activity of methylenetetrahydrofolate reductase, stopping DNA synthesis in order to suppress tumor growth.
The researchers sequenced two alleles of the gene encoding the MTHFR enzyme in DNA samples of 564 individuals belonging to different races and nationalities. In accordance with the results of earlier studies, the authors found 3 common variants of the gene. At the same time, they identified 11 unusual variants, the frequency of occurrence of each of which was less than 1%.
After that, they synthesized genes for each of the enzyme variants and embedded them in yeast cells. Yeast is an ideal model for studying human metabolism, because it uses a variety of enzymes similar to human enzymes and co-factor vitamins and minerals.
The authors found that 4 different mutations affect the functioning of the human enzyme in yeast cells. One of these mutations is well studied: one copy of it is contained in the genomes of about 30% of people and 2 copies in the genomes of 9% of people. The addition of folic acid to the yeast culture medium made it possible to restore the full functionality of both the most common variant of the mutant enzyme and the other variants, except for one that is most rarely found in the population.
In later work, the researchers identified 30 more variants of the MTHFR enzyme and tested 15 of them. More than half of these mutations affect the activity of the enzyme, and it can differ by 100 times. In most cases, the insufficient activity of the enzyme can be partially or completely neutralized with the help of additional folic acid intake.
The effect of increased MTHFR activity on human health has not been fully elucidated, but at least one of its defects leads to an increase in the content of homocysteine in the blood, associated with an increased risk of heart disease and stroke. Taking folic acid, whose ability to prevent birth defects and the development of cardiovascular diseases and cancer has been known for a long time, should reduce the level of this metabolite in people with a mutant variant of MTHFR, which will positively affect their health.
In total, there are more than 600 enzymes in the human body that use vitamins or minerals as cofactors. According to the authors, each person has about 5 rare mutant variants of enzymes and, possibly, several other, more common variants, the functioning of which can be improved with the help of vitamins and trace elements.
Small variations in enzyme activity may be the cause of conflicting results of clinical trials, including studies of the activity of vitamins and mineral supplements. In the future, when processing the results of such tests, it will be necessary to take into account the enzyme profiles of the participants.
Currently, the authors are studying the mechanisms by which cofactors restore the activity of defective enzymes. They suggest that these substances stabilize the enzyme molecule in a conformation that ensures maximum catalytic activity. They also believe that if this assumption is confirmed, the new principle can help specialists involved in the synthesis of drugs ("drag design").
Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of ScienceDaily 07.06.2008