Effect of ketogenic diet on blood pressure: A GRADE-Assessed systematic review and meta-analysis of randomized controlled trials

Aims: Cardiovascular diseases (CVDs) are major causes of mortality around the world. High blood pressure (BP) or hypertension is one of the most significant predisposing factors to CVDs. Ketogenic diets (KDs) have been the center of attention for their possible health benefits. The aim of this analysis is to study the impact of KDs on BP through the existing literature. Data synthesis: We investigated the impact of KDs on systolic and diastolic blood pressures (SBP and DBP) conducted in the format of randomized controlled trials (RCTs). Four online databases (PubMed/Medline, SCOPUS, Cochrane Library, and Google Scholar) were searched from inception up to November 2022. Subgroup analyses were carried out to find the sources of heterogeneities. Twenty-three RCTs with 1664 participants were identified. KDs did not exert any significant impacts on SBP (WMD: -0.87 mmHg, 95% CI: -2.05, 0.31) nor DBP (WMD: -0.11 mmHg, 95% CI -1.14, 0.93). Subgroup analyses did not reveal any further information. Also, non-linear dose-response analysis could not detect any associations between the percentage of calorie intake from fat in the KD format and BP levels. Conclusion: KDs do not seem to be effective in improving BP. Nonetheless, further investigations are recommended to examine the proportion of fat intake needed to induce favorable clinical impacts. (c) 2023 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.