Folate Metabolism in Ethnic Russians Living in the Arkhangelsk Region

The state of physiological processes of folate and homocysteine metabolism depends on a number of modifiable and unmodifiable factors. The former include nutritional status, unhealthy lifestyle (smoking, alcohol abuse and imbalanced diet), while the latter include hereditary factors (unfavourable alleles of genes encoding folate metabolism enzymes with low functional activity). The purpose of this paper was to evaluate the influence of phenotypic (lifestyle) and genetic (polymorphism of folate metabolism genes) factors on folic acid and homocysteine metabolism in a sample of ethnic Russians born and living in the Arkhangelsk Region. Materials and methods. This is a prospective one-stage cross-sectional study. The sample consists of healthy ethnic Russians aged between 18 and 44 years and living in the Arkhangelsk Region (n = 318). We analysed lifestyle questionnaires and laboratory test results for folate metabolism, i.e. concentrations of homocysteine and vitamins B9 and B12. Molecular genetic testing of genes encoding folate metabolism enzymes (MTHFR, MTR and MTRR) was performed. Results. We analysed the frequency distribution of alleles of folate metabolism genes and found an association between the carriage of an unfavourable T allele (CT and TT genotypes) of the MTHFR 677 C>T (rs1801133) polymorphism and elevated serum homocysteine levels (p < 0.001). The research demonstrated that in subjects consuming a sufficient amount of folate-rich plant foods daily, the level of folic acid is statistically significantly higher (p < 0.001) and homocysteine lower (p < 0.001) than in those with insufficient plant food intake. Homocysteine level in long-term smokers was found to be significantly higher than in nonsmoking participants (p < 0.001).