Muscle strength and function
Evidence from some randomized controlled trials shows that daily supplementation with MCTs can boost exercise-induced increases in muscle strength and function in adults with or at risk of sarcopenia and frailty.[1][2][3]
Cognitive performance
Some observational studies have shown that a higher serum caprylic acid (a.k.a. octanoic acid) concentration in the body is associated with a lower risk of mild cognitive impairment.[4][5] Some small randomized controlled trials have shown that daily supplementation with MCTs can enhance cognitive performance (working memory and executive function) in adults without known health conditions,[6][7][8][9] and some evidence shows that daily supplementation with MCTs can improve cognitive performance in people with mild to moderate Alzheimer's disease.[10] However, this has only been observed in people with an APOE4-/- genotype (i.e., people who do not carry an apolipoprotein E (APOE) genotype, which predisposes people to a high risk of dementia).[10] Furthermore, meta-analyses of studies that examined the effects of MCTs on dementia show large heterogeneity in the effect size between the studies and do not currently support the use of MCTs in the treatment or prevention of Alzheimer’s disease.[11][12][13] In general, studies in this field also have a high risk of bias due to poor study designs and conflicts of interest.[11][12][13]
Fat oxidation
Small randomized controlled trials have also shown that daily supplementation with MCTs can increase fat oxidation rates during a high-fat meal[14] and during low-intensity exercise in men without known health conditions.[15][16] However, these studies typically compare MCTs to carbohydrates or a calorie-free placebo rather than other types of fats (e.g., long-chain triglycerides). Consequently, the observed effects might not be specific to medium-chain triglycerides.
Body weight
Some research has also examined the effects of MCTs on body composition and body weight. Some meta-analyses have found that supplementation with MCTs can lower body weight,[17][18] but the effect is very small and variable among the studies.[17][18][19] Furthermore, the studies are small and few in number, and the majority of studies are affected by conflicts of interest from commercial bias.[17][18][19]
Energy intake
While MCTs do not appear to affect the appetite or circulating concentrations of gut hormones,[20][21] the potential effect of MCTs on body weight might be driven by the moderate decrease in daily energy intake that one meta-analysis found.[20] However, this effect was demonstrated by pooling diverse study types involving acute and chronic ingestion of MCT supplements as well as diets that contained different amounts of MCTs. Consequently, further high-quality trials and meta-analyses are needed to understand the effects of MCTs on body weight regulation.