Intake of the plant lignans secoisolariciresinol, matairesinol, lariciresinol, and pinoresinol in Dutch men and women

Enterolignans (enterolactone and enterodiol) are phytoestrogens that are formed by the colonic microflora from plant lignans. They may reduce the risk of certain types of cancer and cardiovascular diseases. Initially, only secoisolariciresinol and matairesinol were considered to be enterolignan precursors, but recently, new precursors such as lariciresinol and pinoresinol were identified. We recently developed a lignan database including 4 major enterolignan precursors. We used this database to estimate lignan intake in a representative sample of Dutch men and women participating in the Dutch Food Consumption Survey, carried out in 1997-1998. Median total lignan intake among 4660 adults (19-97 y old) was 979 mu g/d. Total lignan intake did not differ between men and women; thus, the lignan density of the diet was significantly higher (P < 0.001) in women than in men. Lignan intake was strongly skewed toward higher values (range 43-77584 mu g/d, mean 1241 mu g/d). Lariciresinol and pinoresinol contributed 75% to lignan intake, whereas secoisolariciresinol and matairesinol contributed only 25%. The major food sources of lignans were beverages (37%), vegetables (24%), nuts and seeds (14%), bread (9%), and fruits (7%). Lignan intake was significantly (P < 0.001) correlated with intake of dietary fiber (r = 0.46), folate (r = 0.39), and vitamin C (r = 0.44). Older persons, nonsmokers, vegetarians, and persons with a low BMI or a high socioeconomic status had higher lignan intakes than their counterparts. In brief, this study shows that the amount of enterolignan precursors in the diet has previously been largely underestimated.