Project description:Lifestyle-based interventions, including dietary modifications, can reduce dementia risk. In this regard, dietary supplementation with medium-chain triglycerides (MCT) shows promise against Alzheimer’s disease in humans. This effect is widely presumed to be mediated by hepatic conversion of MCT into circulating ketones. However, the physiological and cellular mechanisms underlying the benefits of MCT remain understudied, particularly in the context of Alzheimer’s disease. Here, we investigated the cellular and molecular changes occurring in the brain and systemically in response to dietary supplementation with MCT versus a classic ketogenic diet (KD). The experimental design consisted of comparing a 70% carbohydrate control diet to either a control diet supplemented with 10% MCT or a carbohydrate-free high fat KD. Diets were tested in two Alzheimer’s disease mouse models, slow-progressing 3xTg-AD mice that model pre-symptomatic/early stages and rapidly-progressing 5xFAD mice that model late stages of the disease. We found that MCT supplementation and KD both improved hippocampal-dependent spatial learning and memory, increased dendritic spine density of hippocampal neurons, and modulated hippocampal expression of genes associated with mitochondrial functions, synaptic structure, and insulin signaling in Alzheimer’s disease mouse models. However, unlike KD,MCT supplementation did not elevate circulating ketones, suggesting different mechanisms. Indeed, while MCT enhanced the peripheral insulin response of Alzheimer’s disease mice, KD conversely unveiled their latent metabolic vulnerability, increasing their hyperglycemia, body weight gain, and adiposity. The systemic metabolic disturbances of Alzheimer’s disease mice correlated with transcriptomic alterations in hepatic lipid metabolism and ketogenesis genes and increased lipid droplet accumulation. These liver metabolic abnormalities were partially reversed by both MCT supplementation and KD, but in distinct ways. Notably, KD selectively triggered hepatic neutral lipid depletion and prominent proinflammatory gene expression while MCT down-regulated expression of cholesterol-related genes. Collectively, these findings reveal that MCT supplementation in the context of Alzheimer’s disease improves cognition and systemic metabolism without elevating circulating ketone levels.

Project description:BackgroundThree clinical trials have examined the chronic effects of medium-chain triglycerides (MCTs) on muscle mass and function in frail older adults (mean age 85 years old). However, significant increases in muscle mass and some muscle function relative to long-chain triglycerides (LCTs) have yet to be shown, possibly due to the small number of participants in each trial.ObjectiveWe re-analyzed these previous clinical trials to clarify whether MCT supplementation can increase muscle mass and function.AnalysisAfter adding post hoc tests to the original report, we compared changes in measurement between the MCT and LCT groups in the first 2 trials and conducted a combined data analysis.MethodsIn a combined data analysis, changes from baseline in measurements at the 3 months intervention in the MCTs- and LCTs-containing groups were assessed by analysis of covariance adjusted for baseline values of each measurement, age, sex, BMI, allocation to trial, habitual intakes in energy, protein, leucine, octanoic acid, decanoic acid, and vitamin D during the baseline period. The Mann-Whitney U test was used to analyze data on right and left knee extension times.ResultsMCT supplementation for 3 months increased muscle function relative to LCT supplementation with and without an L-leucine (1.2 g) and vitamin D (cholecalciferol, 20 μg)-enriched supplement. In a combined data analysis (n = 29 in MCTs, n = 27 in LCTs), relative to supplementation with 6 g LCTs/day, supplementation with 6 g MCTs/day at dinner for 3 months significantly increased body weight (adjusted mean change from baseline: MCTs 1.2 vs. LCTs 0.2 kg, p = 0.023), right arm muscle area (MCTs 1.4 vs. LCTs-0.7 cm2, p = 0.002), left calf circumference (p = 0.015), right-hand grip strength (MCTs 1.6 vs. LCTs 0.3 kg, p = 0.017), right knee extension time (p = 0.021), left knee extension time (p = 0.034), walking speed (p = 0.002), and number of iterations in leg open and close test (p < 0.001) and decreased right triceps skinfold thickness (p = 0.016).ConclusionIn frail older adults, supplementation for 3 months with a low dose (6 g/day) of MCTs (C8:0 and C10:0) increased muscle mass and function. These findings indicate the potential for the practical use of MCTs in daily life in treating sarcopenia.

Dataset Information

Medium-chain triglycerides may improve memory in non-demented older adults: a systematic review of randomized controlled trials.

Background

Methods

Results

Conclusions

Publications

Medium-chain triglycerides may improve memory in non-demented older adults: a systematic review of randomized controlled trials.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets