Background:
The Dietary Approaches to Stop Hypertension (DASH) diet (rich in fruit (F), vegetables (V), low-fat dairy, and fiber, and reduced in saturated fat and cholesterol) lowered blood pressure (BP) and low-density lipoprotein cholesterol after 8 weeks compared with a typical American diet. However, direct effects on cardiovascular damage are unknown.
Hypothesis:
The DASH diet reduces cardiac injury, strain, and inflammation compared to a typical American diet.
Methods:
The DASH feeding study was a 3-arm, parallel-design, randomized controlled trial of adults with systolic BP (SBP) <160 mm Hg and diastolic BP (DBP) of 80-95 mm Hg, without cardiovascular disease (CVD) and not taking BP medications. Participants were randomized to 8 weeks of monitored feeding with: a typical American diet with 3.6 servings of F/V per day (ref), a F/V-enriched diet (8.5 servings of F/V per day), or the DASH diet (9.6 servings of F/V per day). Calories were adjusted to keep weight constant throughout feeding. We compared the effects of these diets on 3 cardiac biomarkers: high-sensitivity cardiac troponin I (hs-cTnI), N-terminal b-type pro natriuretic peptide (NT-proBNP), and high-sensitivity C-reactive protein (hs-CRP), measured in stored serum collected at baseline and after feeding.
Results:
Of the 257 participants with available specimens, 33% were aged >50 yrs, 48% were women, and 56% were non-white. Mean baseline SBP/DBP was 131/85 mmHg. Compared to control, the F/V-enriched diet reduced hs-cTnI by 53% (95% CI: 18, 73;
P
= 0.008) and NT-proBNP by 24% (95% CI: 7, 38;
P
= 0.01) (
Figure
). Similarly, compared to control, DASH reduced hs-cTnI by 49% (95% CI: 11, 71;
P
= 0.02) and NT-proBNP by 20% (95% CI: 2, 35;
P
= 0.04). Hs-CRP did not differ between diets, and none of the markers differed between DASH and F/V-enriched diets.
Conclusions:
In adults with high BP but not CVD, both F/V-enriched and DASH diets lowered sensitive markers of cardiac injury and strain over 8 weeks. Our study demonstrates early, direct cardiovascular benefits from diets rich in F/V.
Blood Pressure Differences Associated With Optimal Macronutrient Intake Trial for Heart Health (OMNIHEART)–Like Diet Compared With a Typical American Diet
