Supplementation of Regular Diet With Medium-Chain Triglycerides for Procognitive Effects: A Narrative Review

Abstract

It is now widely accepted that ketosis (a physiological state characterized by elevated plasma ketone body levels) possesses a wide range of neuroprotective effects. There is a growing interest in the use of ketogenic supplements, including medium-chain triglycerides (MCT), to achieve intermittent ketosis without adhering to a strict ketogenic diet. MCT supplementation is an inexpensive and simple ketogenic intervention, proven to benefit both individuals with normal cognition and those suffering from mild cognitive impairment, Alzheimer's disease, and other cognitive disorders. The commonly accepted paradigm underlying MCT supplementation trials is that the benefits stem from ketogenesis and that MCT supplementation is safe. However, medium-chain fatty acids (MCFAs) may also exert effects in the brain directly. Moreover, MCFAs, long-chain fatty acids, and glucose participate in mutually intertwined metabolic pathways. Therefore, the metabolic effects must be considered if the desired procognitive effects require administering MCT in doses larger than 1 g/kg. This review summarizes currently available research on the procognitive effects of using MCTs as a supplement to regular feed/diet without concomitant reduction of carbohydrate intake and focuses on the revealed mechanisms linked to particular MCT metabolites (ketone bodies, MCFAs), highlighting open questions and potential considerations.

Reference gene expression stability within the rat brain under mild intermittent ketosis induced by supplementation with medium-chain triglycerides

“…Rats were given MCT (Jarrow Formulas, Inc., Los Angeles CA, USA) at a dose of 2 ml/kg daily by oral gavage during a 6-hour fasting period or an equivolume of water without fasting (control animals) for 4 weeks. Adjusted for metabolic rate [ 15 ], this dosage corresponds to approximately 20 g/day of MCT for an adult human subject, a typical dose used in human studies [ 16 ]. Animals were sacrificed by decapitation.…”

Ketogenic Diet and Breast Cancer: Recent Findings and Therapeutic Approaches

“…A valid alternative is the variant based on medium-chain triglycerides (MCTKD), with a higher proportion of carbohydrates and proteins. Medium-chain triglycerides produce more ketones per kilocalorie of energy than long-chain triglycerides used in the classic KD, require less fat intake to induce ketosis, and are metabolized more rapidly [49,50].…”

MCT-Induced Ketosis and Fiber in Rheumatoid Arthritis (MIKARA)—Study Protocol and Primary Endpoint Results of the Double-Blind Randomized Controlled Intervention Study Indicating Effects on Disease Activity in RA Patients

“…Low doses between 10 g and 20 g of MCTs elicit the most gastrointestinal symptoms [32]. Moreover, for a ketogenic effect of <1 mmol/L lower doses are also sufficient [33,34]. Based on published data, the dosage of MCT was defined as 15 g per serving.…”