Supplementation with mixed nuts does not improve inflammatory biomarkers or dietary inflammatory potential in post-myocardial infarction: a secondary analysis of the DICA-NUTS trial.

Abstract

Systemic inflammation is an independent predictor of cardiovascular events, and nut-enriched diets are often recommended after acute myocardial infarction (AMI). However, the effects of mixed nuts on inflammatory biomarkers in secondary prevention remain unclear. This study evaluated the impact of incorporating mixed nuts into the Brazilian Cardioprotective Diet (DICA Br) on systemic inflammation and dietary inflammatory potential in post-AMI patients. This secondary analysis of the DICA-NUTS randomized controlled trial included 170 adults post-AMI, assigned to receive either the DICA Br diet alone (n = 85) or the same diet supplemented with 30 g/day of mixed nuts (10 g each of peanuts, cashews, and Brazil nuts; n = 85) for 16 weeks. Plasma concentrations of interleukins (IL-2, IL-4, IL-6, IL-10), tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), and C-reactive protein (CRP) were measured at baseline and post-intervention. Dietary inflammatory potential was assessed using the Dietary Inflammatory Index (DII®) and the energy-adjusted DII (E-DII™). No significant between-group differences were observed for any inflammatory biomarker or for DII and E-DII scores. Within the DICA group, IL-4 levels decreased (-4.56 pg/mL; 95% CI -9.00 to -0.11; p = 0.045), with a concurrent increase in the IFN-γ/IL-4 ratio (0.035; 95% CI 0.003 to 0.067; p = 0.04). IFN-γ concentrations were higher in the lowest DII tertile (p = 0.046) and inversely correlated with DII scores (ρ = -0.15; p = 0.006). Supplementation with 30 g/day of mixed nuts did not significantly modify inflammatory biomarkers or improve the anti-inflammatory potential of the diet over 16 weeks in post-AMI patients. ClinicalTrials.gov identifier: NCT03728127.