We prospectively followed 214,108 men and women in 3 cohorts who did not have
cardiovascular disease or cancer at baseline. Diet was repeatedly assessed using a validated food frequency questionnaire every 2-4 years since baseline.
RESULTS: During 5,517,225 person-years of follow-up, we documented 10,244 CHD cases, including 6,283 nonfatal
myocardial infarction and 3,961 fatal CHD cases. In multivariable-adjusted analyses, comparing extreme quintiles, the pooled hazard ratios of CHD were 0.85 (95% CI: 0.79-0.92) for total
lignans, 0.76 (95% CI: 0.71-0.82) for
matairesinol, 0.87 (95% CI: 0.81-0.93) for
secoisolariciresinol, 0.89 (95% CI: 0.83-0.95) for
pinoresinol, and 0.89 (95% CI: 0.83-0.95) for
lariciresinol (all P values for trend ≤0.003). Nonlinear relationships were found for total
lignan,
matairesinol, and
secoisolariciresinol: the risk reduction plateaued at intakes above approximately 300 μg/d, 10 μg/d, and 100 μg/d, respectively (P < 0.01 for all nonlinearity). The inverse associations for total
lignan intake appeared to be more apparent among participants with higher total fiber intake (P = 0.04 for interaction). In addition,
lignan intake was more strongly associated with plasma concentrations of
enterolactone when fiber intake was higher.
CONCLUSIONS: Increased long-term intake of
lignans was associated with a significantly lower risk of total CHD in both men and women. Possible synergistic effects may exist between
lignan and fiber intake in relation to CHD risk reduction, possibly through enhancing the production of enterolignans.