Influence of vitamin intake and MTHFR polymorphism on the levels of DNA damage in tobacco farmers

ABSTRACT

Background: Genetic damage may occur spontaneously under normal metabolic circumstances, inadequate intake of nutrients, and excessive exposure to environmental mutagens. Objectives: To evaluate the influence of the intake of micronutrients vitamin B₁₂, vitamin B₆, and folate and of the polymorphism methylenetetrahydrofolate reductase (MTHFR) C677T on the induction of DNA damage in tobacco farmers. Methods: The study involved 66 men and 44 women engaged in tobacco cultivation in the region of Venâncio Aires (Rio Grande do Sul state, Brazil). Peripheral blood samples were collected to analyze DNA damage using the Comet assay, the micronucleus (MN) test and MTHFR C677T polymorphism. Dietary intake was evaluated based on the mean values obtained from three 24-h diet recall questionnaires, and nutrient intake data were computerized and estimated in the Food Processor SQL 10.9 program. The statistical tests used to generate the stated results were Kruskal–Wallis test, Exact Fisher’s test, and multivariate linear regression analysis. Results: DNA damage was significantly higher in individuals who had an inadequate intake of folate, vitamin B₁₂, and vitamin B₆ (P < 0.01) assessed by Comet assay. In relation to MN test results, buccal cells showed MN frequency higher in individuals with inadequate intake of vitamin B₆ (P < 0.01). No difference was observed in MN lymphocytes frequency. No significant association was detected between MTHFR C677T polymorphism and DNA damage in tobacco farmers. Conclusion: Our results suggest that folate, vitamin B₁₂, and vitamin B₆ deficiency may be associated with genotoxic effect in individuals exposed to pesticides.

KEYWORDS:

• Folate
• DNA damage
• MTHFR C677T polymorphism
• tobacco farmers
• vitamin

Acknowledgments

The authors thank the farmers who participated in this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by a grant from the Brazilian Research Agency (CNPq), Conselho Nacional para o Desenvolvimento de Pessoal de Ensino Superior (CAPES), and Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS).