Substituting Potatoes with Other Food Groups and Type 2 Diabetes Risk: Findings from the Diet, Cancer, and Health Study.

Background: Although potatoes are considered a dietary staple in some cultures, evidence suggests that their impact on type 2 diabetes (T2D) risk is nuanced, with preparation methods and dietary patterns playing crucial roles. Investigating the substitution effects of replacing potatoes with other foods is required to inform dietary recommendations for lowering T2D risk.

Objective: The objective of this was to investigate associations between the substitution of potatoes (excluding fries/chips) with other food groups (vegetables, whole grains, refined grains, red meat, processed meat, poultry, fish, and dairy) and the risk of T2D.

Methods: The diet of participants from the prospective Danish Diet, Cancer, and Health study (DCH) was measured at baseline (1993-1997) by a food frequency questionnaire. Participants were followed up for incident T2D from baseline until 2012. Associations between the substitution of potatoes (total, boiled, and mashed) with other food groups and incident T2D was assessed by multivariable Cox proportional hazards model.

Results: In 54,793 DCH study participants, during a median follow-up of 16.3 y, 7693 incident T2D cases were recorded. A 26% lower risk of T2D was observed when 50 g/d of potatoes were substituted with the same amount of whole grains [hazard ratio and 95% confidence interval (CI): 0.74 (0.70, 0.79)]. Similarly, a lower risk of T2D was observed upon substituting 25 g/d of potatoes with an equivalent amount of green leafy [HR (95% CI): 0.79 (0.74, 0.83)], cruciferous [HR (95% CI): 0.87 (0.83, 0.92)], and yellow/orange/red vegetables [HR (95% CI): 0.97 (0.96, 0.99)]. Conversely, a higher risk of T2D was observed when potatoes were substituted with poultry [HR (95% CI): 1.08 (1.02, 1.15)], red meat [HR (95% CI): 1.06 (1.02, 1.10)], and processed meat [HR (95% CI): 1.17 (1.11, 1.23)]. Replacing boiled potatoes with red meat or poultry was associated with a higher risk of T2D compared with replacing mashed potatoes.

Conclusions: Substituting potatoes with whole grains and most types of vegetables was associated with a lower risk of T2D, whereas substituting potatoes with poultry, red meat, and processed meat was associated with a higher risk.