Potato consumption and the risk of overall and cause specific mortality in the NIH-AARP study

BACKGROUND: Potato consumption has been hypothesized to be associated with higher risk of hypertension, diabetes, and colorectal cancer. OBJECTIVE: The aim of this study was to examine the association between potato consumption and the risk of overall and cause specific mortality in the large prospective National Institutes of Health–AARP (NIH-AARP) Study. DESIGN: The NIH-AARP study recruited 566,407 persons, aged 50–72 years in 1995–1996. We excluded subjects that reported a history of chronic disease at baseline. Potato consumption data from a validated food frequency questionnaire completed at baseline was used in Cox proportional hazard models to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for overall and cause specific mortality. Final models were adjusted for potential risk factors for mortality. RESULTS: Among 410,701 participants included in this analysis, 76,921 persons died during the 15.6 years of follow-up. Eating baked, boiled, or mashed potatoes, French fries or potato salad seven or more times per week was associated with higher risk of overall mortality, in models adjusted only for age and sex (HR (C4 vs C1) = 1.17, 95%CI = 1.13, 1.21). These results were attenuated in fully adjusted models (HR (C4 vs C1) = 1.02, 95%CI = 0.97, 1.06). Potato consumption was not associated with risk of mortality caused by cancer (HR (C4 vs C1) = 1.04, 95%CI = 0.97, 1.11), heart disease (HR (C4 vs C1) = 1.00, 95%CI = 0.93, 1.09), respiratory disease (HR (C4 vs C1) = 1.16, 95%CI = 0.99, 1.37), or diabetes (HR (C4 vs C1) = 0.91, 95%CI = 0.71, 1.19). We tested for an association with different preparation methods and found limited evidence for differences by preparation method. The only statistically significant association was that for French fry consumption with cancer-related mortality (HR (C4 vs C1) = 1.27, 95%CI = 1.02, 1.59), a finding for which uncontrolled confounding could not be ruled out. CONCLUSION: We find little evidence that potato consumption is associated with all-cause or cause-specific mortality.