In 2015, and on the basis of an Institute of Medicine report requested by Congress, the restriction on white potatoes in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), was lifted;   The rationale for removing these limitations on potatoes included their high potassium content and appropriate potassium intake is associated with diminished risk for hypertension,  furthermore , there was insufficient evidence of their health effects. On the international front, the World Health Organization does not include potatoes as vegetables. Although potassium supplementation may be beneficial for chronic disease prevention, in particular prevention of hypertension, a six week feeding trial of 164 pre-hypertensive and hypertensive people found that diets rich in protein or monounsaturated fat reduced blood pressure compared with diets rich in carbohydrates. Because potatoes are high in both glycemic carbohydrates and potassium, their effect on risk of hypertension is unclear.

To assess the relation between potato intake and hypertension, researchers pooled data from three prospective cohort studies,  Nurses’ Health Study (NHS; n=121 700 women, aged 30-55 at the time of cohort inception in 1976), the Nurses’ Health Study II (NHS II; n=116 430 women, aged 25-42 at cohort inception in 1989), and the Health Professionals Follow-up Study (HPFS; n=51 529 men, aged 40-75 at cohort inception in 1986), and adjusted for many potential confounding variables (e.g., age, ethnicity, body-mass index, smoking status, physical activity, medications). A diagnosis of hypertension by a health professional was self reported on the baseline and biennial questionnaires.

Of >187,000 participants without hypertension at baseline, 78,000 participants reported receiving diagnoses of hypertension during follow-up. Participants who consumed ≥1 serving daily of baked, boiled, or mashed potatoes or French fries had excess risk for hypertension compared with those who consumed ≤1 serving monthly (multivariate hazard ratio, 1.12). Similar results were obtained for consumption of baked, boiled, or mashed potatoes alone and consumption of French fries alone (≥4 servings weekly vs. ≤1 serving monthly). However, potato chip consumption alone was not associated with increased risk.

Citation(s):Borgi L et al. Potato intake and incidence of hypertension: Results from three prospective US cohort studies. BMJ 2016 May 17; 353:i2351. (http://dx.doi.org/10.1136/bmj.i2351)