Determinants of dietary lignan intake in a representative sample of young Spaniards: association with lower obesity prevalence among boys but not girls.

Lignan-rich diets have been associated with favorable health effects through improved metabolic profile. In this study, we hypothesized that dietary lignan intake could be also associated with childhood obesity. We studied prevalent obesity in relation to lignan intake within the enKid study that involved 3438 children, adolescents and young adults (2-24 years old). Participant's dietary records were used to calculate lignan dietary intake using a lignan composition database adapted to the Spanish diet. The mean intake of the dietary lignans was calculated as ~1 mg/day, corresponding mainly (37%) to pinoresinol. No gender differences were found, but lignan intake was positively associated with age, physical activity level and dietary fiber intake, and negatively with the intake of polyunsaturated and saturated fatty acids. The main sources of dietary lignans were refined wheat, olive oil and whole-wheat bread. A strong association between dietary lignan intake and prevalent obesity was found only for boys, with odds ratio (highest versus lowest quartile of lignan intake) of 0.34 (95% confidence interval, 0.17-0.70) after adjusting for main confounders, including dietary fiber. Boys with the highest lignan-rich products including cereals, whole-grain products and olive oil, presented less cases of obesity in this representative sample of Spanish children and adolescents. It is unknown whether this association implies an active role of dietary lignans on obesity development, or is merely an indicator of a healthier lifestyle.