Lignan Intake and Mortality Among Adults with Incident Type 2 Diabetes-Prospective Cohort Studies

Background: Lignans are polyphenolic compounds abundant in plant-based foods such as seeds, whole grains, and certain fruits and vegetables and may lead to favorable metabolic health. It remains to be elucidated regarding the role of lignan consumption in the etiology of premature deaths among individuals with diabetes.

Objectives: To prospectively examine the association between post-diagnosis lignan intake and mortality among individuals with type 2 diabetes (T2D).

Methods: We analyzed data from two prospective U.S. cohorts, the Nurses' Health Study (1984-2020) and Health Professionals Follow-up Study (1986-2022). Average daily consumption of total and individual lignans were calculated, and post-diagnosis lignan intakes were cumulatively averaged. Multivariable-adjusted Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between lignan intake and mortality.

Results: Among 8,465 incident T2D cases contributing 116,026 person-years of follow-up, 4,372 deaths were documented, including 1,318 from cardiovascular disease (CVD) and 752 from cancer. The pooled multivariable-adjusted HRs (95% CIs) of all-cause mortality comparing the highest versus the lowest quintiles of post-diagnosis lignan intake were 0.83 (0.74, 0.94) for total lignans, 0.89 (0.80, 0.99) for matairesinol (MAT), 0.78 (0.69, 0.87) for secoisolariciresinol (SECO), 0.91 (0.81, 1.01) for pinoresinol (PINO), and 0.92 (0.82, 1.03) for lariciresinol (LARIC). Higher post-diagnosis SECO intake was also significantly associated with lower CVD and cancer mortality. Changes in lignan intake from pre- to post-diagnosis showed similar favorable associations: 0.83 (0.75, 0.93) for total lignans, 0.86 (0.77, 0.96) for MAT, and 0.81 (0.72, 0.90) for SECO. The associations of lignan intake were significantly stronger among non-white individuals.

Conclusions: Among individuals with T2D, a higher intake of lignans, particularly SECO, was significantly associated with reduced overall, CVD, and cancer mortality. Minority groups may particularly benefit from lignan intake, although further studies are warranted to substantiate this observation.