Dairy intake, blood pressure and incident hypertension in a general British population: the 1946 birth cohort.

PURPOSE

We aimed to examine the association between intake of different subgroups of dairy products and blood pressure and incident hypertension 10 years later, adjusting for confounding factors.

METHODS

We studied 1,750 British men and women from the 1946 British birth cohort from 1989 to 1999 (age 43 and 53 years, respectively). Diet was assessed by 5-day food diaries using photographs in the estimation of portion size. Systolic (sbp) and diastolic (dbp) blood pressure and prevalent hypertension were assessed at age 43 and 53 years. Linear regression and logistic regression were used to examine 10-year blood pressure levels and incident hypertension by baseline dairy intake.

RESULTS

There was a weak non-significant trend of a protective effect of total dairy intake on blood pressure and incident hypertension, but no evidence for a dose-response relationship (OR for incident hypertension: 0.88 (95% CI 0.68;1.14) 2nd vs. 1st tertile and 0.93 (95% CI 0.72;1.18) 3rd vs. 1st tertile). Higher intake of low-fat and fermented dairy was linked to a higher sbp but in a nonlinear manner. Adjustment for other dietary factors, health behaviours and BMI attenuated these associations.

CONCLUSIONS

Total dairy intake and specific dairy subgroups were not associated with blood pressure and incident hypertension among a representative sample of British adults after adjustment for confounding factors.