Healthy diet reduces markers of cardiac injury and inflammation regardless of macronutrients: Results from the OmniHeart trial

Despite diet being a first-line strategy for preventing cardiovascular disease, the optimal macronutrient profile remains unclear. We studied the effects of macronutrient profile on subclinical cardiovascular injury and inflammation. OmniHeart was a randomized 3-period, crossover feeding study in 164 adults with high blood pressure or hypertension (SBP 120–159 or DBP 80–99 mm Hg). Participants were fed each of 3 diets (emphasizing carbohydrate (CARB), protein (PROT), or unsaturated fat (UNSAT)) for 6-weeks, with feeding periods separated by a washout period. Weight was held constant. Fasting serum was collected at baseline while participants ate their own diets and after each feeding period. High-sensitivity cardiac troponin I (hs-cTnI) and high-sensitivity C-reactive protein (hs-CRP) were measured in stored specimens. The average age was 53.6 years, 55% were African American, and 45% were women. At baseline, the median (25th-percentile, 75th-percentile) hs-cTnI was 3.3 ng/L (1.9, 5.6) and hs-CRP was 2.2 mg/L (1.1, 5.2). Compared to baseline, all 3 diets reduced hs-cTnI: CARB –8.6% (95%CI: −16.1, −0.4), PROT –10.8% (−18.4, −2.5), and UNSAT −9.4% (−17.4, −0.5). Hs-CRP was similarly changed by −13.9 to −17.0%. Hs-cTnI and hs-CRP reductions were of similar magnitudes as SBP and low-density lipoprotein cholesterol (LDLc) but were not associated with these risk-factor reductions (P-values = 0.09). There were no between-diet differences in hs-cTnI and hs-CRP reductions. Healthy diet, regardless of macronutrient emphasis, directly mitigated subclinical cardiac injury and inflammation in a population at risk for cardiovascular disease. These findings support dietary recommendations emphasizing healthy foods rather than any one macronutrient. Trial Registration: This trial is registered at clinicaltrials.gov, number: NCT00051350; URL: https://clinicaltrials.gov/ct2/show/NCT00051350. •Three healthy diets led to reduction in high-sensitivity troponin, a marker of subclinical cardiac injury.•Inflammation, measured by high-sensitivity CRP, was also reduced by all three healthy diets.•These changes were not explained alone by improvement in hypertension or hyperlipidemia.•All three healthy diets can be recommended to help reduce cardiovascular risk.