Inverse association between dairy intake and hypertension: the Rotterdam Study.

BACKGROUND Little is known about the effect of different types of dairy food products on the development of hypertension. OBJECTIVE The objective was to determine whether the incidence of hypertension in older Dutch subjects is associated with intake of dairy products. DESIGN We examined the relation between dairy intake and incident hypertension in 2245 participants of the Rotterdam Study aged > or =55 y with complete dietary and blood pressure data, who were free of hypertension at baseline (1990-1993). Blood pressure was reexamined in 1993-1995 and in 1997-1999. Hazard ratios (HRs) with 95% CIs for 2- and 6-y incidence of hypertension were obtained in quartiles of energy-adjusted dairy intake, with adjustment for age, sex, BMI, smoking, educational level, dietary factors, and intake of alcohol and total energy. RESULTS Risk of hypertension after 2 y of follow-up (664 incident cases) was inversely associated with dairy product intake. After adjustment for confounders, HRs (95% CIs) were 1.00, 0.82 (0.67, 1.02), 0.67 (0.54, 0.84), and 0.76 (0.61, 0.95) in consecutive quartiles of total dairy product intake (P for trend = 0.008). Corresponding HRs for low-fat dairy products were 1.00, 0.75 (0.60, 0.92), 0.77 (0.63, 0.96), and 0.69 (0.56, 0.86) (P for trend = 0.003). Analysis of specific types of dairy products showed an inverse association with milk and milk products (P for trend = 0.07) and no association with high-fat dairy or cheese (P > 0.6). After 6 y of follow-up (984 incident cases), the associations with hypertension were attenuated to risk reductions of approximately 20% for both total and low-fat dairy products between the extreme quartiles of intake (P for trend = 0.07 and 0.09, respectively). CONCLUSION Intake of low-fat dairy products may contribute to the prevention of hypertension at an older age.