{"entity":{"id":"idea-nl-ketogenic-gbm-definitive-trial","kind":"idea","name":"One definitive ketogenic diet trial in glioblastoma, then stop","aka":[],"tldr":"Patients with brain tumours are sold ketogenic diets on the strength of mouse data and small feasibility studies. A single adequately powered trial with dietitian support would either prove it or let clinicians say clearly that it does not work.","summary":"Fifteen years of feasibility studies have shown ketogenic diets are tolerable for a few months in glioblastoma and have not shown efficacy. Because the diet is marketed directly to patients and is a common reason for conflict with treating teams, the cost of not knowing is high. No company will fund a diet trial; a philanthropic or cooperative-group trial with adherence biomarkers (blood ketones), a pre-registered stopping rule and a commitment to publish either way is the appropriate instrument.","asOf":"2026-09-08","links":[{"label":"Bottleneck evidence (Misinformation and unproven therapies): Johnson et al., Cancer misinformation and harmful information on Facebook and other social media (JNCI 2022)","url":"https://doi.org/10.1093/jnci/djab141"}],"tags":[],"related":[],"cancers":["glioblastoma"],"sections":["nutrition-lifestyle"],"technologies":["ketogenic-diet-glioblastoma","metabolic-therapy","nutrition-screening-mnt"],"targets":[],"drugs":["temozolomide"],"companies":[],"institutions":[],"pathways":[],"terms":["warburg-effect-diet-claims","unproven-diet-claims","warburg-effect"],"trials":["ergo2"],"people":[],"bottlenecks":["b-misinformation","b-negative-results","b-funding-allocation"],"keyPapers":["paper-johnson-j-natl-cancer-inst"],"journals":[],"dependsOn":[],"notes":[],"hypothesis":"A supervised ketogenic diet maintained for six months alongside standard chemoradiation and temozolomide does not improve overall survival in newly diagnosed glioblastoma compared with a standard healthy diet (null hypothesis to be tested with power to detect a 3-month median difference).","rationale":"The Warburg rationale is plausible but tumours adapt to use ketones and lactate; steroids undermine ketosis; ERGO2 was null but brief. A definitive answer protects patients from an intervention with real costs (weight loss, quality of life, expense) if it fails, and mobilises adoption if it works.","test":"Randomised phase 2/3 (about 300 patients) in newly diagnosed IDH-wildtype glioblastoma, stratified by MGMT status and steroid use, with dietitian-delivered ketogenic diet vs Mediterranean-style diet, ketone-verified adherence, OS primary endpoint, quality of life and body composition secondary, and pre-registered publication regardless of result.","maturity":"early-clinical","actor":"philanthropy","cost":"medium","horizonYears":5},"route":"/ideas/idea-nl-ketogenic-gbm-definitive-trial/","neighbours":{"cancer":[{"id":"glioblastoma","kind":"cancer","name":"Glioma & glioblastoma","route":"/cancers/glioblastoma/"}],"section":[{"id":"nutrition-lifestyle","kind":"section","name":"Diet, Exercise & Lifestyle","route":"/fronts/nutrition-lifestyle/"}],"technology":[{"id":"ketogenic-diet-glioblastoma","kind":"technology","name":"Ketogenic diets in glioblastoma","route":"/technologies/ketogenic-diet-glioblastoma/"},{"id":"metabolic-therapy","kind":"technology","name":"Metabolic therapy: starving the tumour of a nutrient","route":"/technologies/metabolic-therapy/"},{"id":"nutrition-screening-mnt","kind":"technology","name":"Oncology nutrition assessment and medical nutrition therapy","route":"/technologies/nutrition-screening-mnt/"}],"drug":[{"id":"temozolomide","kind":"drug","name":"Temozolomide","route":"/drugs/temozolomide/"}],"term":[{"id":"unproven-diet-claims","kind":"term","name":"Unproven diet claims (alkaline, juice, 'anti-cancer' diets)","route":"/terms/unproven-diet-claims/"},{"id":"warburg-effect","kind":"term","name":"Warburg effect","route":"/terms/warburg-effect/"},{"id":"warburg-effect-diet-claims","kind":"term","name":"Warburg-effect diet claims ('sugar feeds cancer')","route":"/terms/warburg-effect-diet-claims/"}],"trial":[{"id":"ergo2","kind":"trial","name":"ERGO2: ketogenic diet and fasting during re-irradiation of recurrent glioma","route":"/trials/ergo2/"}],"bottleneck":[{"id":"b-negative-results","kind":"bottleneck","name":"Failures are hidden","route":"/bottlenecks/b-negative-results/"},{"id":"b-funding-allocation","kind":"bottleneck","name":"Funding follows fashion, not burden","route":"/bottlenecks/b-funding-allocation/"},{"id":"b-misinformation","kind":"bottleneck","name":"Misinformation and unproven therapies","route":"/bottlenecks/b-misinformation/"}],"paper":[{"id":"paper-johnson-j-natl-cancer-inst","kind":"paper","name":"Cancer Misinformation and Harmful Information on Facebook and Other Social Media: A Brief Report","route":"/key-papers/paper-johnson-j-natl-cancer-inst/"}]}}