Longitudinal association of dairy consumption with the changes in blood pressure and the risk of incident hypertension: the Framingham Heart Study

We aimed to examine the longitudinal association of dairy consumption with the changes in blood pressure (BP) and the risk of incident hypertension (HTN) among adults. This study included 2636 Framingham Heart Study Offspring Cohort members who participated in the 5th through 8th examinations (1991-2008) and were free of HTN at their first examination during the follow-up. Data collected at each examination included dietary intake (by a validated FFQ), BP (following standardised procedures) and anti-hypertensive medication use (by physician-elicited self-report). HTN was defined as systolic BP (SBP)≥140 mmHg, or diastolic BP (DBP)≥90 mmHg or anti-hypertensive medication use. We used repeated-measure and discrete-time hazard regressions to examine the associations of dairy consumption with the annualised BP change (n 2075) and incident HTN (n 2340; cases=1026), respectively. Covariates included demographic, lifestyle, overall diet quality, metabolic factors and medication use. Greater intakes of total dairy foods, total low-fat/fat-free dairy foods, low-fat/skimmed milk and yoghurt were associated with smaller annualised increments in SBP and a lower risk of projected HTN incidence. However, with the exception of total dairy foods and yoghurt, these inverse associations with HTN risk were attenuated as the follow-up time increased. For yoghurt, each additional serving was associated with 6 (95 % CI 1, 10) % reduced risk of incident HTN. Total dairy and total low-fat/fat-free dairy intakes were found to be inversely related to changes in DBP. Dairy consumption, as part of a nutritious and energy-balanced diet pattern, may benefit BP control and prevent or delay the onset of HTN.