BMC Cardiovasc Disord. 2026 Jul 7. doi: 10.1186/s12872-026-06189-7. Online ahead of print.
ABSTRACT
BACKGROUND: The cardiovascular impact of ketogenic diets (KD) remains debated. In this review, KD refers to adult dietary interventions intended to induce nutritional ketosis through marked carbohydrate restriction, while acknowledging that ketogenic diet therapy (KDT) is a broader umbrella term encompassing several protocol variants.
METHODS: We systematically searched PubMed, Embase, Web of Science, and the Cochrane Library from inception to March 2026, and we additionally searched gray literature sources (ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform, medRxiv, conference proceedings, and reference lists). Eligible studies included randomized controlled trials (RCTs), prospective cohorts, and observational studies of adult KD interventions (generally < 10% of energy from carbohydrate or < 50 g/day). Primary outcomes were lipid changes; secondary outcomes included glycemia, anthropometrics, and blood pressure; exploratory outcomes were mortality and atherosclerosis. Random-effects meta-analyses generated pooled estimates. The protocol was not prospectively registered.
RESULTS: Twenty-four studies (20 RCTs, 2 prospective cohorts, 1 non-randomized clinical trial, and 1 pilot intervention; >47,000 participants) were included. Compared with control diets, KD increased low-density lipoprotein cholesterol (LDL-C) (mean difference [MD] + 12.2 mg/dL, 95% CI 7.5 to 16.9; I2 = 67.7%) and total cholesterol, while high-density lipoprotein cholesterol (HDL-C) rose modestly. Triglycerides decreased overall (MD -16.1 mg/dL, 95% CI -20.3 to -11.8; I2 = 17.1%). KD also improved fasting glucose, glycated hemoglobin, body weight, body mass index, and systolic blood pressure. Cohort evidence suggested lower all-cause mortality but no clear reduction in cardiovascular mortality. Imaging evidence for atherosclerosis was limited and mixed.
CONCLUSIONS: KD was associated with improvements in adiposity, glycemic control, and blood pressure, but also with higher LDL-C and total cholesterol. Evidence for clinical cardiovascular endpoints remains limited, mixed, and mostly low certainty, supporting individualized risk-benefit assessment rather than universal adoption of KD.
PMID:42414899 | DOI:10.1186/s12872-026-06189-7