Dietary potato intake and risks of type 2 diabetes and gestational diabetes mellitus

Evidence regarding associations between potato consumption and type 2 diabetes (T2D) and gestational diabetes mellitus (GDM) risks is accumulating. This study aims to synthesize the evidence by conducting a meta-analysis of available studies.PubMed, Web of Science, EMBASE and Cochrane Library were searched (up to August 2020) to retrieve all eligible studies on the associations of interest. The risk estimates with 95% confidence intervals (CIs) were summarized using random- or fixed-effects model based on heterogeneity. Meta-analyses were performed for East and West regions separately. Dose-response relationship was assessed using data from all intake categories in each study.A total of 19 studies (13 for T2D; 6 for GDM) were identified, including 21,357 T2D cases among 323,475 participants and 1516 GDM cases among 29,288 pregnancies. Meta-analysis detected a significantly positive association with T2D risk for total potato (RR: 1.19 [1.06, 1.34]), baked/boiled/mashed potato (RR: 1.08 [1.00, 1.16]), and French fries/fried potato (RR: 1.33 [1.03, 1.70]) intakes among Western populations. Dose-response meta-analysis demonstrated a significantly increased T2D risk by 10% (95% CI: 1.07, 1.14; P for trend<0.001), 2% (95% CI: 1.00, 1.04; P for trend = 0.02) and 34% (95% CI: 1.24, 1.46; P for trend<0.001) for each 80 g/day (serving) increment in total potato, unfried potato, and fried potato intakes, respectively. As for GDM, summarized estimates also suggested a higher though non-significant GDM risk for total potato (RR: 1.19 [0.89, 1.58]), and French fries/fried potato (RR: 1.03 [0.97, 1.09]) intakes in Western countries. In the dose-response meta-analysis, a significantly increased GDM risk was revealed for each daily serving (80 g) intakes of total potato (RR: 1.22; 95% CI: 1.06, 1.42; P for trend = 0.007) and unfried potato (RR: 1.26; 95% CI: 1.07, 1.48; P for trend = 0.006).This study suggests that higher potato intake is associated with higher T2D risk among Western populations. The positive relationship presents a significant dose-response manner. Wisely controlled potato consumption may confer potential glucometabolic benefits.