Impact of the ketogenic diet as a dietary approach on cardiovascular disease risk factors: a meta-analysis of randomized clinical trials.

ABSTRACT

BACKGROUND: Cardiovascular diseases (CVD) remain the leading cause of mortality globally, and the scarcity of scientific evidence regarding the impact of ketogenic diets on CVD risk factors necessitates urgent attention and redress. OBJECTIVES: This meta-analysis evaluates the impact of the ketogenic diet on CVD risk factors compared with control diets through randomized controlled trials (RCTs). METHODS: The study was registered in advance in the PROSPERO database (CRD42023491853). A systematic search was conducted across PubMed, Web of Science, EMBASE, and Cochrane Library to identify relevant RCTs. Fixed and random effects were employed to calculate the mean differences and 95% confidence intervals (CIs) for changes in CVD risk factors pre- and postketogenic diet intervention. RESULTS: A total of 27 RCTs with 1278 participants were analyzed. The ketogenic diet intervention presented increase in total cholesterol (mean differences 0.36 mmol/L; 95% CI 0.15, 0.57; I2 85.1%), low-density lipoprotein cholesterol (mean differences 0.35 mmol/L; 95% CI 0.20, 0.50; I2 73.9%) and high-density lipoprotein cholesterol (mean differences 0.16 mmol/L; 95% CI 0.09, 0.23; I2 86.7%) concentrations. Reductions were observed in the triglyceride (mean differences -0.20 mmol/L; 95% CI -0.29, -0.11; I2 72.2%), blood glucose (mean differences -0.18 mmol/L; 95% CI -0.33, -0.02; I2 76.4%), blood insulin (mean differences -8.32 pmol/L; 95% CI -14.52, -2.12; I2 81.5%), diastolic blood pressure (mean differences -1.41 mmHg; 95% CI -2.57, -0.26; I2 49.1%), weight (mean differences -2.59 kg; 95% CI -3.90, -1.28; I2 87.4%), and body mass index (mean differences -1.59 kg/m2; 95% CI -2.32, -0.86; I2 84.5%) concentrations after implementing ketogenic diets. CONCLUSIONS: Although the ketogenic diet demonstrates benefits in terms of triglyceride, blood pressure, weight, and glycemic control, its impact on CVD risk factors, especially the elevated total cholesterol and low-density lipoprotein cholesterol concentrations, warrants a cautious approach.