A Prospective Investigation of the Association Between Urinary Excretion of Dietary Lignan Metabolites and Weight Change in US Women.

Results from animal studies have consistently suggested that lignans play a role in the regulation of in body weight, but evidence from human studies has been limited. We examined the associations between urinary excretion of enterolactone and enterodiol, the major intestinal microbial metabolites of dietary lignans, and 10-year prospective weight change using data from 2 well-characterized cohort studies of US women: the Nurses' Health Study (2000-2010) and Nurses' Health Study II (1997-2007). Urinary excretion levels of enterolactone and enterodiol were measured at baseline. Associations with prospective weight change were analyzed using a multivariable-adjusted linear mixed-effects model. We observed that women in the highest quartile of urinary excretion of total lignans had significantly lower baseline body mass indices (weight in kilograms divided by height in meters squared) (mean, 24.6, 95% confidence interval (CI): 23.9, 25.2) than did those in the lowest quartile (mean, 27.7, 95% CI: 27.0, 28.4; P for trend < 0.01). Compared with women in the lowest quartile of enterodiol excretion, those in the highest quartile gained 0.27 kg/year less weight (95% CI: 0.12, 0.41; P for trend < 0.01) during the 10-year follow-up. The association was borderline significant for enterolactone (for the fourth vs. first quartile, least square mean of weight change rate = -0.14 kg/year, 95% CI: -0.29, 0.00). Our data suggest that higher urinary excretion of lignan metabolites, especially enterodiol, is associated with modestly slower weight gain.