Potatoes and risk of obesity, type 2 diabetes, and cardiovascular disease in apparently healthy adults: a systematic review of clinical intervention and observational studies

Background: Potatoes have been related to increased risks of obesity, type 2 diabetes (T2D), and cardiovascular disease (CVD) mainly because of their high glycemic index. Objective: We conducted a systematic review to evaluate the relation between intake of potatoes and risks of obesity, T2D, and CVD in apparently healthy adults. Design: MEDLINE, Embase, the Web of Science, and the Cochrane Central Register of Controlled Trials were searched for intervention and prospective observational studies that investigated adults without any known illnesses at baseline, recorded intake of potatoes, and measured adiposity (body weight, body mass index, or waist circumference), cases of T2D, cases of cardiovascular events, or risk markers thereof. Results: In total, 13 studies were deemed eligible; 5 studies were related to obesity, 7 studies were related to T2D, and one study was related to CVD. Only observational studies were identified; there were 3 studies with moderate, 9 studies with serious, and one study with critical risk of bias. The association between potatoes (not including french fries) and adiposity was neutral in 2 studies and was positive in 2 studies. French fries were positively associated with adiposity in 3 of 3 studies. For T2D, 2 studies showed a positive association, whereas 5 studies showed no or a negative association with intake of potatoes and T2D. French fries were positively associated with T2D in 3 of 3 studies that distinguished this relation. For CVD, no association was observed. Conclusions: The identified studies do not provide convincing evidence to suggest an association between intake of potatoes and risks of obesity, T2D, or CVD. French fries may be associated with increased risks of obesity and T2D although confounding may be present. In this systematic review, only observational studies were identified. These findings underline the need for long-term randomized controlled trials.