Effects of a dairy‐rich diet on blood pressure (BP): moderating effects of intracellular calcium [(Ca)i ] status

Because (Ca)i is postulated to influence BP, we assessed the hypotensive effects of a dairy‐rich diet and whether the effects differed according to changes in (Ca)i. Using a randomized, 3‐period, cross‐over design, 23 stage 1 hypertensive adults were fed 3 experimental diets (5 wk each); high dairy, high fruits and vegetables diet (D‐F&V; 30% fat, 7% saturated fat (SFA), 3.4 servings/d dairy), a low dairy, high fruits and vegetables diet (F&V; 30% fat, 7% SFA, 0.4 servings/d dairy), and an average Western diet (AWD; 36% fat, 15% SFA, 0.4 servings/d dairy). Systolic (SBP) and diastolic (DBP) blood pressure, calcitriol, and erythrocyte (Ca)i were determined. SBP and DBP were significantly reduced by ~2 mm Hg following both D‐F&V and F&V diets vs. AWD (P<0.05 for each). The D‐F&V diet significantly lowered calcitriol and (Ca)i vs. the two dairy‐poor diets (P<0.01 for each). The reduction in (Ca)i correlated with the fall in DBP (r=0.55, P<0.03). Subjects who responded to the D‐F&V diet by significantly reducing (Ca)i exhibited significantly greater drops in DBP on the D‐F&V (−14 ± 3.4 mm Hg) vs. the F&V (−10 ± 3.4 mm Hg) and AWD diets (−8 ± 3.4 mm Hg; diet x group interaction, P<0.02). The results suggest that (Ca)i is responsive to diet and that a dairy‐rich diet produces an ideal intracellular environment, which may result in improved BP. Funding: Dairy Management Inc., GCRC of Penn State University NIH M01 RR10732