Dietary amino acids and the risk of hypertension in a Dutch older population: the Rotterdam Study

Background: Inverse associations between dietary protein and hypertension have been reported, which may be attributed to specific amino acids. Objective: We examined whether the intake of glutamic acid, arginine, cysteine, lysine, or tyrosine was associated with blood pressure (BP) levels (n = 3086) and incident hypertension (n = 1810) in the Rotterdam Study. Design: We calculated BP levels in quartiles of amino acid intake as a percentage of total protein intake (% of protein) with adjustment for age, sex, BMI, smoking, alcohol intake, education, and dietary factors. Subsequently, we used Cox proportional models that included the same confounders to evaluate the associations between specific amino acid intake and hypertension incidence. Results: Glutamic acid contributed most to protein intake (21% of protein), whereas lysine provided 7%, arginine 5%, tyrosine 4%, and cysteine 1.5%. A higher intake of tyrosine (similar to 0.3% of protein) was significantly related to a 2.4-mm Hg lower systolic BP (P-trend = 0.05) but not to diastolic BP (P = 0.35). The other amino acids were not significantly associated with BP levels in a cross-sectional analysis. During 6 y of follow-up (7292 person-years), 873 cases of hypertension developed. None of the amino acids were significantly associated with incident hypertension (HR: 0.81-1.18; P-trend > 0.2). Conclusion: Our data do not suggest a major role for glutamic acid, arginine, lysine, tyrosine, or cysteine intake (as % of protein intake) in determining population BP or risk of hypertension. Am J Clin Nutr 2013;97:403-10.