Efeito da intervenção com folato dietético e óleo de avelã nos níveis de metilação dos genes LEP e POMC, peso corporal e perfil lipídico em mulheres com excesso de peso

Abstract

The selection of candidate genes for studies with obesity, such as leptin (LEP) and proopiomelanocortin (POMC), can provide information on the epigenetic mechanisms related to dietary intervention underlying the regulation of body weight and lipid profile. The objective of this research was to evaluate the effect of the intervention with dietary folate and hazelnut oil on the levels of methylation of the LEP and POMC genes, body weight and lipid profile of overweight women. The present study were linked to a larger project entitled " II Cycle of Diagnosis and Intervention of the Most Prevalent Food, Nutritional and Transmissible Situation of the Population of the Municipality of João Pessoa / PB (II DISANDNT / JP)". This is a double-blind, placebo, controlled intervention study, developed with a subsample of the population of the aforementioned project, consisting of 40 women classified as overweight or obese. These were evaluated before and after the intervention in relation to food consumption, anthropometric measurements, biochemical analyzes and methylation levels of the LEP and POMC genes. Participants were randomized into four groups: group 1 (G1) received 191 μg / day of dietary folate and 1 hazelnut oil capsule; group 2 (G2) received 191 μg / day of folate and 1 placebo capsule; Group 3 (G3) received 94 μg / day of folate and 1 capsule of hazelnut oil; and group 4 (G4) was instructed to maintain eating habits. The statistical analysis was performed with an analysis of variance (ANOVA) comparing the four groups, and afterwards, using Student's t-test and Willcoxon, to analyze each group, using the software R. We found the participants with an average age of 44 ± 10.1 years, and after the intervention showed a reduction in the methylation levels of the genes studied in the three intervention groups, in the LEP gene: G1 (p = 0.008), G2 (p = 0.003) and G3 (p = 0.005); in the POMC gene: G1 (p = 0.019), G2 (p = 0.021) and G3 (p = 0.01), and weight loss in G2 (p = 0.005) and G3 (p = 0.000). In the lipid profile, G1 reduced the levels of LDL-c (p = 0.043), HDL-c (p = 0.000) and triglycerides (p = 0.045); in G3 there was a reduction in the levels of total cholesterol (p = 0.001), LDL-c (p = 0.000) and HDL-c (p = 0.005), and in G4 a reduction in the values of total cholesterol (p = 0.004), LDL- c (p = 0.001), HDL-c (p = 0.000) and triglycerides (p = 0.009). The effect of eating a diet containing moderate dietary folate and hazelnut oil capsule in reducing the methylation levels of the LEP and POMC genes and decreasing body weight without altering energy consumption, and improving the lipid profile was demonstrated for the first time, being a potential result for treatment and prevention of obesity.