Efficacy of Low-Carbohydrate Ketogenic Diet as an Adjuvant Cancer Therapy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: The role of low-carbohydrate ketogenic diet (LCKD) as an adjuvant therapy in antitumor treatment is not well established. This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to investigate the efficacy of LCKD as an adjuvant therapy in antitumor treatment compared to non-ketogenic diet in terms of lipid profile, body weight, fasting glucose level, insulin, and adverse effects; Methods: In this study, databases such as PubMed, Web of Science, Scopus, CINAHL, and Cochrane trials were searched. Only RCTs that involved cancer participants that were assigned to dietary interventions including a LCKD group and a control group (any non-ketogenic dietary intervention) were selected. Three reviewers independently extracted the data, and the meta-analysis was performed using a fixed effects model or random effects model depending on the I-2 value or p-value; Results: A total of six articles met the inclusion/exclusion criteria. In the overall analysis, the post-intervention results = standard mean difference, SMD (95% CI) showed total cholesterol (TC) level = 0.25 (-0.17, 0.67), HDL-cholesterol = -0.07 (-0.50, 0.35), LDL-cholesterol = 0.21 (-0.21, 0.63), triglyceride (TG) = 0.09 (-0.33, 0.51), body weight (BW) = -0.34 (-1.33, 0.65), fasting blood glucose (FBG) = -0.40 (-1.23, 0.42) and insulin = 0.11 (-1.33, 1.55). There were three outcomes showing significant results in those in LCKD group: the tumor marker PSA, p = 0.03, the achievement of ketosis p = 0.010, and the level of satisfaction, p = 0.005; Conclusions: There was inadequate evidence to support the beneficial effects of LCKDs on antitumor therapy. More trials comparing LCKD and non-KD with a larger sample size are necessary to give a more conclusive result.

Automated summary

This systematic review and meta-analysis investigated the efficacy of low-carbohydrate ketogenic diet (LCKD) as an adjuvant therapy in antitumor treatment compared to non-ketogenic diet. The results showed significant outcomes in terms of prostate-specific antigen (PSA), achievement of ketosis, and level of satisfaction in the LCKD group. However, overall there was insufficient evidence to support the beneficial effects of LCKDs on antitumor therapy, highlighting the need for more trials with larger sample sizes for a conclusive result.