A insegurança alimentar e nutricional : correlação epigenética do gene BDNF, status social e de saúde em agricultores familiares de café do Caparaó capixaba

Abstract

Background: The association between insecurity about food and nutrition (INSAN) and violation of the human right to food (HRFN) is already known. In addition, the association between work on small family farms, poor health conditions, and INSAN has been proposed in several countries. However, the impact of living with INSAN on epigenetics, including the use of methylation studies has received little attention. The brain-derived neurotrophic factor, or BDNF, is important for the maintenance of brain functions, but stress can cause methylation of the promoter region of the BDNF gene, and this epigenetic change is associated with depression. Objective: To evaluate factors that might be associated with INSAN, including the methylation of exon I of BDNF and the living conditions of family farmers. Methods: Farmers from small family farms, 18 to 60 years of age, from 22 rural communities of 11 cities in the state of South Espirito Santo, southeastern Brazil participated in the study by answering a questionnaire about socioeconomic characteristics, ownership and use of land, behavior, health, and working conditions. The INSAN evaluation was carried out using the Brazilian Food Insecurity Scale. Methylation of exon I of the BDNF gene was examined by methylation-specific PCR. Body mass index (BMI) and biochemical and molecular analyses were performed. Logistic regression models were used to verify factors associated with INSAN. Results: The prevalence of INSAN and methylation were 23.68% and 39.01%. The occurrence of INSAN was associated the methylation of the exon I promoter of the BDNF gene, Odds Ratio (ORa) = 5.03 (95% CI 1.98 – 12.83); extra work off one’s own property, ORa = 3.36 (95% CI 1.23 – 9.21); land size (hectares), ORa = 0.77 (95% CI 0.67 - 0.90); and number of real-life symptoms and/or diseases, ORa = 1.12 (95% CI 1.04-1.20). Conclusions: The occurrence of INSAN in the members of small family farms, correlates with the conditions of a higher methylation rate of BDNF, the need to work outside the home because of low income, smaller size of the property, and greater numbers of diseases/symptoms reports.