Boosting Lignan Intake in T2D May Lower Mortality Risk

TOPLINE:

Higher intake of lignans — a group of plant-based antioxidants abundant in flaxseeds, whole grains, coffee, and some fruits and vegetables — is associated with a reduced risk for all-cause mortality and lower cardiovascular disease (CVD) mortality in individuals diagnosed with type 2 diabetes (T2D), especially in non-White individuals.

METHODOLOGY:

• Studies show that consuming more lignans, found in plant-based foods like seeds, whole grains, fruits, vegetables, and coffee, has been linked to lower all-cause mortality in the general population and may lower the risks for T2D, but few studies have examined the health impact of lignan intake among individuals after a T2D diagnosis.
• Researchers analyzed the data of 8465 participants with incident T2D from two prospective US cohorts spanning three decades, one composed of female registered nurses and the other male healthcare professionals.
• The average daily intake of total and four individual lignans, secoisolariciresinol (SECO) and matairesinol (MAT), pinoresinol, and lariciresinol, was calculated from food frequency questionnaires updated every 2-4 years during follow-up.
• T2D diagnosis was self-reported by participants and verified with a supplementary questionnaire that collected data on glucose and A1c levels and symptoms and treatments for T2D.
• The outcomes included mortality from all causes, CVD, cancer, and other causes following the diagnosis of T2D.

TAKEAWAY:

• The risk for all-cause mortality was 17% ( 95% CI, 6%-26%) lower in participants in the highest vs the lowest quintile of total lignan intake post T2D diagnosis, with an 11% (95% CI, 1%-20%) and 22% (95% CI, 13%-31%) lower risk for all-cause mortality associated with the intake of MAT and SECO, respectively.
• Higher SECO intake post T2D diagnosis was associated with a 22% (95% CI, 4%-37%) lower risk for CVD mortality, a 28% (95% CI, 5%-45% ) lower risk for cancer mortality, and an 18% (95% CI, 4%-31%) lower risk for mortality due to other non-CVD and noncancer causes.
• Increase in lignan intake from before to after T2D diagnosis demonstrated favorable associations with all-cause mortality, resulting in a 17% (95% CI, 7%-25%) lower risk in those in the highest vs lowest quintile of lignan intake. Similar outcomes were noted with the intake of MAT and SECO.
• In stratified analyses, non-White individuals had lower risk for total mortality when consuming the highest vs lowest quintile of lignans than White individuals, post-diagnosis (lower risk: non-White, 68%; 95% CI, 24%-86%; White, 16%; 95% CI, 5%-25%).

IN PRACTICE:

“These results underscore the potential of lignan intake in lowering risk of premature death among individuals with T2D, highlighting its role as a potential valuable component of dietary strategies for health maintenance in this population,” the authors wrote.

SOURCE:

This study was led by Binkai Liu, Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston. It was published online in The American Journal of Clinical Nutrition.

LIMITATIONS: 

The analysis was limited to four major subtypes of lignans, preventing the exploration of other lignans such as sesamin. Residual confounding could not be eliminated owing to the observational nature of the study. The study population predominantly consisted of White US healthcare professionals, thereby limiting the generalizability of the findings. The stronger associations observed in the small number of non-White participants need to be replicated in a more racially diverse population.

DISCLOSURES:

This study was supported by grants from the US National Institutes of Health. No potential conflicts of interest were reported. The top 20 food contributors to the four lignan totals in each cohort after flaxseed are listed in a supplementary table.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.