Effect of nuts on lipid profile and inflammatory biomarkers in atherosclerotic cardiovascular disease: a systematic review and meta-analysis of randomized controlled trials

Background: Nut-enriched diets positively impact lipid and inflammatory profile biomarkers in meta-analyses in the context of primary cardiovascular prevention. However, primary studies on secondary cardiovascular prevention are scarce and controversial. Objectives: This systematic review and meta-analysis aimed to assess the effect of nut supplementation on lipid and inflammatory profile biomarkers in individuals with atherosclerotic cardiovascular disease, and the frequency of adverse events. Methods: Six databases were used for research: PubMed, EMBASE, BVS, Cochrane Library, Web of Science, and ClinicalTrials.gov, until February 2023, with no language restrictions. The Cochrane Handbook for Systematic Reviews of Interventions methodology and the PICO strategy were used. We performed random-effects meta-analyses to compare nut-enriched diets vs. control diets for pre-post intervention changes. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system assessed the evidence's certainty, and the protocol was registered in the PROSPERO database under the identifier CRD42020163456.