Potato Consumption and Risk of Type 2 Diabetes Mellitus: A Harmonized Analysis of 7 Prospective Cohorts

Data on the relation of potato consumption with risk of type 2 diabetes (T2D) are limited and inconsistent. It is unclear whether the plant-based diet index (PDI), which is a novel and comprehensive tool to assess overall dietary pattern, modifies the association of potato intake with T2D.

We examined the association of total, combined baked, boiled, and mashed potatoes and fried potatoes with risk of T2D and test the interaction between PDI score and potato consumption on T2D risk.

We conducted a de novo, harmonized, individual-level data from 7 United States cohorts (N = 105,531). Cox regression was used to estimate hazard ratios (HRs) separately in each cohort adjusting for anthropometric, demographic, and lifestyle factors and cohort-specific results were pooled using an inverse-variance weighted method.

Mean age ranged from 25 to 72 y, 65% women, and mean consumption of total potatoes ranged from 1.9 to 4.3 times per week. In the primary analysis, total potato intake was not associated with T2D risk: multivariable adjusted HR of 1.01 (95% confidence interval [CI]: 0.95, 1.08) for consumption of 1-2 servings/wk; 1.01 (95% CI: 0.93, 1.10) for >2-3 servings/wk; 1.05 (95% CI: 0.99, 1.12) for >3 to <5 servings/wk; and 1.07 (95% CI: 0.99, 1.16) for 5+ servings/wk compared with no potato intake. In secondary analyses, consumption of combined baked, boiled, and mashed potatoes was not associated with T2D risk, whereas fried potato consumption was positively associated with T2D risk: HR were 1 (ref), 1.07 (95% CI: 1.02, 1.12), and 1.12 (95% CI: 1.03, 1.22) for intake frequency of 0/wk, >0 to 1/wk, and >1/wk, respectively (P-trend = 0.04). There was no significant interaction between PDI score and potato consumption on T2D risk.

Although consumption of total potato is not associated with T2D risk, a modest elevated risk of T2D is observed with fried potato consumption.