Supplementation of medium-chain triglycerides combined with docosahexaenoic acid improves cognitive function in Chinese older adults with mild cognitive impairment: A randomized double-blind, placebo-controlled trial.

BACKGROUND

Medium-chain triglycerides (MCT) and docosahexaenoic acid (DHA) could affect cognitive function, but their combination effects remain unclear. This randomized, double-blind, placebo-controlled trial aimed to evaluate effects of MCT and DHA supplementation, alone or in combination, on mild cognitive impairment (MCI) patients.

METHODS

A total of 280 MCI participants were randomly assigned to the placebo group, MCT group (14 g/d octanoic acid+10 g/d capric acid), DHA group (800 mg/d) and MCT + DHA (14 g/d octanoic acid, 10 g/d capric acid and 800 mg/d DHA) group, 70 individuals per group for 12 months. Cognitive function was assessed at baseline, 6 months and 12 months; blood indicators were analyzed at baseline and 12 months. This study is registered with Chinese Clinical Trial Registry (ChiCTR2200059641).

RESULTS

After 12 months intervention, compared with the placebo group, MCT group, DHA group and MCT + DHA group had statistically significant improvements in full scale IQ (β: 0.107, 95 % CI: 0.006, 0.208; β: 0.135, 95 % CI: 0.034, 0.235; β: 0.136, 95 % CI: 0.035, 0.237), serum total ketone body levels (β: 10.540, 95 % CI: 9.550, 11.531; β: 5.884, 95 % CI: 4.894, 6.875; β: 13.186, 95 % CI: 12.196, 14.176), and decreases in mtDNA deletions (β: -0.370, 95 % CI: -0.648, -0.092; β: -0.335, 95 % CI: -0.613, -0.056; β: -0.427, 95 % CI: -0.705, -0.148) and plasma Aβ42 levels (β: -3.318, 95 % CI: -5.571, -1.064; β: -3.218, 95 % CI: -5.472, -0.965; β: -2.906, 95 % CI: -5.160, -0.653).

CONCLUSIONS

Supplementation of MCT, DHA and their combination for 12 months can significantly improve cognitive function, mitochondria function and increase serum total ketone body levels in MCI individuals. Combined intervention was more beneficial than MCT or DHA alone.