Association between Seaweed Intake and Risk of Type 2 Diabetes Mellitus: A Prospective Cohort Study.

This study aimed to identify the longitudinal association between seaweed and type 2 diabetes mellitus (T2DM) in the Korean population. Data from 148,404 Korean adults aged 40 years and older without a history of T2DM, cardiovascular disease, or cancer at baseline were obtained from the Korean Genome and Epidemiology Study data. The participants' seaweed intake was obtained using a validated semi-quantitative food frequency questionnaire, and the diagnosis of T2DM was surveyed through a self-reported questionnaire during follow-up. The hazard ratio (HR) and 95% confidence interval (CI) for T2DM were calculated using the Cox proportional hazard regression, and the dose-response relationship was analyzed using a restricted cubic spline regression. Participants had a mean follow-up period of 5 years. Participants with the highest seaweed intake had an 7% lower risk of T2DM compared to the group with the lowest intake (95% CI: 0.87-0.99). Interestingly, this association was stronger in those with normal weight (HR: 0.88, 95% CI: 0.81-0.95), while no association was observed in participants with obesity. Spline regression revealed an inverse linear relationship between seaweed intake and T2DM risk in participants with normal weight, showing a trend where increased seaweed intake is related to lower instances of T2DM ( p for nonlinearity = 0.48). Seaweed intake is inversely associated with the onset of T2DM in Korean adults with normal weight.