The study concluded that dietary intake of both total and individual lignans (with the exception of lariciresinol) was associated with a lower risk of developing type 2 diabetes. Comparing the highest to lowest quintiles of intake, total lignan consumption was associated with a 13% lower risk for diabetes, while secoisolariciresinol was associated with the greatest risk reduction for diabetes, a 28% lower risk. Secoisolariciresinol also interacted with BMI and menopausal status, with the highest intake having the largest benefit among people with obesity as well as premenopausal women. A subgroup analysis also found lignan intake to be associated with lower HbA1c and C-reactive protein levels.
It’s worth noting that lignans are metabolized by gut microbiota to enterolignans, previously found to be associated with a lower risk for diabetes, coronary artery disease, and reduced weight gain. It’s not clear why secoisolariciresinol was associated with the largest benefit in this study; it may be because of greater bioavailability or unique metabolism, but it may also be attributed to a diet higher in flaxseeds, whole grain cereals, and tea, each associated with benefit. It should also be noted that even in the highest quintile, lignan intake was low compared to levels reported in other countries, and an apparent dose-dependent effect suggests the possibility of more robust protection with even higher intakes.