LINE-1 methylation levels, a biomarker of weight loss in obese subjects, are influenced by dietary antioxidant capacity

Objectives: Epigenetic markers, and in particular DNA methylation, have come to the fore as new tools in the personalization of the treatment of obesity and its comorbidities. The objectives of the current investigation were to identify epigenetic biomarkers that might be predictive of response to a weight-loss intervention, and to better understand the influence of certain nutrients (particularly antioxidants) on the epigenome. Methods: Global DNA (LINE-1) methylation levels were assessed in peripheral blood mononuclear cells (PBMCs) from 96 obese volunteers of the Metabolic Syndrome Reduction in Navarra study, using a methylation-sensitive high resolution melting approach after bisulfite modification. Results: Baseline LINE-1 DNA methylation levels were significantly higher (5.41%) in high responders (>8% of weight loss) as compared to low responders (<8%) to the energy-restricted treatment. Indeed, a LINE-1 methylation higher than 84.15% may be predictive of a high response to the hypocaloric diet. Statistically significant correlations were found between LINE-1 baseline DNA methylation levels and the response to the treatment involving total fat mass and body weight. Furthermore, LINE-1 baseline methylation levels positively correlated with baseline dietary total antioxidant capacity (TAC). Discussion: LINE-1 methylation levels in PBMCs might be used to predict response to a dietary weight-loss intervention, and seem to be related to the dietary TAC.