Dietary amino acids and the risk of hypertension in a Dutch older population: the Rotterdam Study1–3

Background: Inverse associations between dietary protein and hy-pertension 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 in-cluded 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 (w0.3 % 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 hyperten-sion 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 of protein intake) in determining population BP or risk of hypertension. Am J Clin Nutr doi: 10.3945/ajcn.112.038737