Comparing dietary strategies to manage cardiovascular risk in primary care: Narrative review of systematic reviews

Abstract

Background: Nutrition care in general practice is crucial for cardiovascular disease (CVD) prevention and management, though comparison between dietary strategies is lacking. Aim: To compare best-available (most recent, relevant, and high-quality) evidence for six dietary strategies effective for primary prevention/absolute risk reduction of CVD. Design and setting: A pragmatic narrative review of systematic reviews of randomised trials Methods: We included studies of: (i) adults without history of cardiovascular events; (ii) target dietary strategies postulated to reduce CVD risk, and (iii) direct cardiovascular or all-cause mortality outcomes. Six dietary strategies were examined: energy deficit, Mediterranean-like diet, sodium reduction (salt reduction and substitution), DASH diet, alcohol reduction and fish/fish oil consumption. Reviews were selected based on quality, recency, and relevance. Quality and certainty of evidence was assessed using GRADE. Results: Twenty-five reviews met inclusion criteria; eight were selected as the highest quality, recent, and relevant. Three dietary strategies showed modest, significant reductions in cardiovascular events: energy deficit (relative risk reduction [RRR] 30%, 95%CI 13%-43%), Mediterranean-like diet (RRR 40%, 95%CI 20%-55%), and salt substitution (RRR 30%, 95%CI 7%-48%). Salt reduction, DASH diet, and alcohol reduction showed small, significant reductions in blood pressure, but no reduction in cardiovascular events. Fish/fish oil consumption showed little or no effect; supplementation of fish oil alone showed small reductions in CVD events. Conclusion: For primary prevention, energy deficit, Mediterranean-like diets and sodium substitution have modest evidence for risk reduction of CVD events. Strategies incorporated into clinical nutrition care should ensure guidance is person-centered and tailored to clinical circumstances.