Potato consumption is associated with total and cause-specific mortality: a population-based cohort study and pooling of prospective studies with 98,569 participants

Introduction: The long-term effect of potato consumption on mortality and cardiovascular (CV) and cardiometabolic risk factors is still largely unknown. Using the National Health and Nutrition Examination Surveys (NHANES) 1999-2010, we evaluted the long-term impact of potato intake on total and cause-specific (cardiovascular disease (CVD), cerebrovascular disease and cancer) mortality, and the results were next validated in a systematic review and meta-analysis of cohort studies investigating pooled associations of potato consumption with all-cause and cause-specific death. Material and methods: Vital status up to December 31, 2011 was ascertained in NHANES. Cox proportional hazards were applied to determine the hazard ratios (HRs) and 95% confidence intervals (95% CI) of mortality for each quartile of the potato intake, with the lowest quartile (Q1 - with the lowest intake) used as a reference. In the meta-analysis we used adjusted Cox regression to determine the risk ratio (RR) and 95% CI, as well as random effects models and generic inverse variance methods to synthesize quantitative and pooled data, followed by a leave-one-out method for sensitivity analysis. Results: Among 24,856 participants included, 3433 deaths occurred during the mean follow-up of 6.4 years. In multivariate adjusted models, total (42%), CVD (65%), cerebrovascular (26%) and cancer (52%) mortality risk was greater in individuals with higher potato consumption than those with the lowest intake (p < 0.001 for all comparisons). However, this link disappeared after adjustment for confounding factors. Results from pooling current prospective studies revealed a non-significant association between total (RR = 1.25, 0.98-1.60, p = 0.066), CVD (RR = 0.99, 0.90-1.08, p = 0.845) and stroke mortality (RR = 0.94, 0.85-1.03, p = 0.214) with potato consumption. Individuals with a higher potato intake had a less favorable profile of cardiometabolic factors, including greater waist circumference (97.2 vs. 99.5 cm, p < 0.001) and a less favorable profile of systolic and diastolic blood pressure, levels of triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C) and TG/HDL-C ratio (p < 0.001 for all comparisons). Conclusions: Our results revealed no significant effects of potato intake on long-term mortality rates, whereas higher potato consumption was adversely related to cardiometabolic risk factors. These findings should be taken into consideration for public health strategies, establishing the position for potatoes in the food pyramid.