Efficacy of dietary intervention or in combination with exercise on primary prevention of cardiovascular disease: A systematic review

Background and aim: Lifestyle factors heavily influence the development of cardiovascular disease (CVD); therefore, interventions delivering adequate lifestyle changes may improve the prognosis among patients at cardiovascular (CV) risk. Recently published research on the effectiveness of dietary and exercise intervention programmes, alone or combined, on reducing risk factors associated with CVD as well as preventing CV events have been now assessed. Methods and results: Using the Medline database via PubMed, we searched for prospective studies published between January 2000 and January 2020 assessing the efficacy of dietary interventions alone or in combination with exercise on reducing CV risk factors or events in human adults at risk. Study quality was assessed using the American Dietetic Association Quality Criteria Checklist. From 934 articles, 21 prospective experimental design studies (15 randomized controlled trials (RCTs), one cluster RCT, and five quasi-experimental intervention studies with a control group) met inclusion and exclusion criteria. Most interventions improved at least some markers of CV risk and the most improvement was time devoted to physical activity increased. A low-fat intervention diet seemed to be effective only when coupled with moderate intensity exercise and weight loss, while a Mediterranean diet (MedDiet) intervention without physical activity, decreased both systolic and diastolic blood pressure, major CV events rate and risk of developing type 2 diabetes. Conclusion: The MedDiet appears to have the most beneficial effect on CV events and increased hours of physical training are strongly related to greater improvement of risk factors; nevertheless, adherence to intervention is fundamental as it directly relates to health outcomes. (C) 2020 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.