Vegetable, but not potato, intakes are associated with a lower risk of type 2 diabetes in the Danish Diet, Cancer and Health cohort

OBJECTIVE

To examine the relationship between intakes of a) vegetables/potatoes and incident type 2 diabetes (T2D), and b) explore whether the relationship between vegetable intake and incident T2D is mediated by baseline BMI.

RESEARCH DESIGN AND METHODS

Cross-sectional associations between exposures (baseline intakes of total vegetables, vegetable subgroups, and potatoes), and baseline BMI were assessed by multivariable-adjusted linear regression models. Associations between exposures and incident T2D were examined by multivariable-adjusted Cox proportional hazards models. Mediation by BMI was quantified through exploring natural direct and indirect effects.

RESULTS

Among 54,793 participants of the Danish Diet, Cancer and Health cohort, 7,695 T2D cases were recorded during a median follow-up of 16.3 years. Participants in the highest total vegetable intake quintile (median: 319 g/d) had a 0.35 kg/m2 (95%CI:-0.46, -0.24) lower BMI and a 21% (95%CI: 16, 26%) lower risk of incident T2D after multivariable adjustments, compared to those in the lowest quintile (median: 67 g/d). Baseline BMI mediated ~21% of the association between vegetable intakes and incident T2D. Participants in the highest compared to the lowest (median: 256 vs 52 g/d) potato intake quintile had a 9% (95%CI: 2, 16%) higher risk of T2D after multivariable adjustments with no association found after accounting for underlying dietary patterns. Of the vegetable subclasses, higher intakes of green leafy and cruciferous vegetables were associated with a statistically significantly lower risk of T2D. 

CONCLUSIONS

The findings provide evidence that a higher vegetable, but not potato, intake might help to mitigate T2D risk, partly by reducing BMI.