Brain atrophy in cognitively impaired elderly: the importance of long-chain omega-3 fatty acids and B vitamin status in a randomized controlled trial.
Jerneren F, Elshorbagy AK, Oulhaj A, Smith SM, Refsum H, Smith AD (2015) Am J Clin Nutr. 102(1) 215-21. doi: 10.3945/ajcn.114.103283. Epub 2015 Apr 15.
Web URL: View this and related abstracts via PubMed here.
Increased brain atrophy rates are common in older people with cognitive impairment, particularly in those who eventually convert to Alzheimer disease. Plasma concentrations of omega-3 (ω-3) fatty acids and homocysteine are associated with the development of brain atrophy and dementia.
We investigated whether plasma ω-3 fatty acid concentrations (eicosapentaenoic acid and docosahexaenoic acid) modify the treatment effect of homocysteine-lowering B vitamins on brain atrophy rates in a placebo-controlled trial (VITACOG).
This retrospective analysis included 168 elderly people (≥70 y) with mild cognitive impairment, randomly assigned either to placebo (n = 83) or to daily high-dose B vitamin supplementation (folic acid, 0.8 mg; vitamin B-6, 20 mg; vitamin B-12, 0.5 mg) (n = 85). The subjects underwent cranial magnetic resonance imaging scans at baseline and 2 y later. The effect of the intervention was analyzed according to tertiles of baseline ω-3 fattyacid concentrations.
There was a significant interaction (P = 0.024) between B vitamin treatment and plasma combined ω-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) on brain atrophy rates. In subjects with high baseline ω-3 fatty acids (>590 μmol/L), B vitamin treatment slowed the mean atrophy rate by 40.0% compared with placebo (P = 0.023). B vitamin treatment had no significant effect on the rate of atrophy among subjects with low baseline ω-3 fatty acids (fatty acids were associated with a slower rate of brain atrophy in the B vitamin group but not in the placebo group).
The beneficial effect of B vitamin treatment on brain atrophy was observed only in subjects with high plasma ω-3 fatty acids. It is also suggested that the beneficial effect of ω-3 fatty acids on brain atrophy may be confined to subjects with good B vitamin status. The results highlight the importance of identifying subgroups likely to benefit in clinical trials.
FAB RESEARCH COMMENT:Please find related news items here:
and more information about the VITACOG trial and related research here:
OPTIMA - VITACOG