Determinants of serum enterolactone concentration

Background: The Lignan enterolactone, which is produced by the intestinal m icroflora from dietary precursors, may protect against hormone-dependent ca ncers and cardiovascular diseases. Objective: We examined the cross-sectional associations between the serum e nterolactone concentration and variables related to diet and health in Finn ish adults. Design: Serum enterolactone was measured by using time-resolved fluoroimmun oassay in 2380 Finnish men and women aged 25-64 y who were participating in a cross-sectional national survey in 1997. Background information was coll ected with self-administered questionnaires and the diet was assessed with a food-frequency questionnaire. Results: The median serum enterolactone concentration was 13.8 nmol/L (rang e: 0-95.6 nmol/L) in men and 16.6 nmol/L (range: 0-182.6 nmol/L) in women. Multiple regression analyses showed positive associations in men between th e serum enterolactone concentration and constipation, consumption of whole- grain products, and intake of fruit and berries. In women, the serum entero lactone concentration was positively and independently associated with cons umption of vegetables, subject age, and constipation and was negatively ass ociated with smoking. Furthermore, female subjects of normal weight had sig nificantly higher serum enterolactone concentrations than did their underwe ight or obese peers. Conclusions: The serum enterolactone concentration varies widely in the pop ulation. Of the variables we examined, the most important determinants of t he serum enterolactone concentration were consumption of lignan-containing foods and constipation; however, these appeared to explain only a small par t of the variation. Therefore, the role of gut microflora in the metabolism of lignans might be very important. Further studies will also be needed to determine the bioavailability and absorption rate of lignans.