Dietary starch intake of individuals and their blood pressure: The international study of macronutrients and micronutrients and blood pressure

OBJECTIVE: Data from the Multiple Risk Factor Intervention Trial show an independent direct association between starch intake and blood pressure in American men at higher risk of coronary heart disease. Cross-sectional data from the International Study of Macronutrients and Micronutrients and Blood Pressure (INTERMAP) were used to assess relations of dietary starch intake to blood pressure in men and women from four countries. METHODS: Data include 83 nutrients from four multipass 24-h dietary recalls and two timed 24-h urine collections; eight blood pressure readings; and questionnaire data, for 4680 participants aged 40-59 years from 17 population samples in Japan, Peoples Republic of China, United Kingdom, and United States of America. RESULTS: In multiple linear regression analyses - adjusted for urinary sodium, urinary potassium, consumption of alcohol, cholesterol, saturated fatty acids, polyunsaturated fatty acids, calcium, and other variables - starch intake higher by two standard deviations (14.1% kJ) was associated with systolic/diastolic blood pressure differences of ĝ̂'1.0/ĝ̂'0.9 mmHg (P ≤ 0.09, P < 0.05). Results were similar with additional control for fiber, magnesium, or phosphorus; reduced to ĝ̂'0.5/ĝ̂'0.7 mmHg (P ≤ 0.47, P ≤ 0.13) with separate adjustment for vegetable protein. Findings were similar for men analyzed separately, for American men, and for American men at higher coronary heart disease risk. CONCLUSION: Our findings indicate that - if any - relations of starch intake to blood pressure are modestly inverse. Current dietary guidelines for hypertension prevention and control remain relevant.