Caffeine intake increases plasma ketones: an acute metabolic study in humans.
Can J Physiol Pharmacol. 2016 Nov 25. Epub 2016 Nov 25. PMID: 28177691
Brain glucose uptake declines during aging and is significantly impaired in Alzheimer's disease. Ketones are the main alternative brain fuel to glucose so they represent a potential approach to compensate for the brain glucose reduction. Caffeine is of interest as a potential ketogenic agent owing to its actions on lipolysis/ lipid oxidation but whether it is ketogenic in humans is unknown. This study aimed to evaluate the acute ketogenic effect of two doses of caffeine in healthy adults (2.5; 5.0 mg/kg) during a 4-hour metabolic study period. Caffeine given at breakfast significantly stimulated ketone production in a dose-dependent manner (+88%; +116%) and also raised plasma free fatty acids. Whether caffeine has long-term ketogenic effects or could enhance the ketogenic effect of medium chain triglycerides remains to be determined. NCT 02694601.