Fruit intake, fruit glycemic load, and type 2 diabetes risk: findings from a community based Korean cohort study

Previous findings on fruit intake and the risk of type 2 diabetes (T2D) have been inconsistent, with limited sex-specific evidence. This study examined the relationship between fruit intake, the fruit-glycemic load (GL), and T2D risk in a Korean cohort using sex-stratified analyses.

Participants from the Ansan and Anseong Cohort were categorized into quartiles of fruit intake and fruit-GL. Nutrient intake, incidence rate of T2D, person-year (yr) during follow-up, and the contribution of individual fruits to the total fruit-GL were assessed. Where appropriate, tests for the linear trend were performed, as were the Cox proportional hazards ratio (HR) tests for T2D by fruit, the fruit-GL, and individual fruits, adjusting for various covariates (expressed as HRs and 95% confidence interval [CI]). Partial correlations were used to determine the associations between fruit intake, fruit-GL, and nutrient intake.

Those in the highest fruit-GL quartile tended to be older, female, and of lower socioeconomic status. During a 19-yr follow-up (73,545.3 person-yrs), 761 new cases of T2D occurred (incidence rate of 10.4). The highest quartile of fruit intake was significantly associated with an increased risk of T2D (HR, 1.45; 95% CI, 1.04-2.03; P = 0.042) with a borderline association with the fruit-GL (HR, 1.36; 95% CI, 0.98-1.91; P = 0.058) in female. Higher watermelon and melon/chamoe intakes were associated with an increased risk of T2D in female. Fruit intake and fruit-GL were positively correlated with carbohydrates and inversely correlated with protein and fat.

Among Korean adult female, excessive fruit consumption (even low fruit-GL) was found to significantly increase diabetes risk, accompanied by higher carbohydrate intake and lower protein intake. These findings suggest that the quantity and quality of fruit, as well as the overall balance of macronutrients, may influence diabetes risk.