Data from the VITACOG trial indicated that high-dose B vitamin supplementation slowed brain wasting (atrophy) in people with mild cognitive impairment (MCI) by 40% but only when omega-3 levels were already high.
On the other hand, in people with low blood levels of omega-3, supplements of folic acid plus vitamins B6 and B12 had no beneficial effect, according to results published in the American Journal of Clinical Nutrition .
In an accompanying editorial, Imrich Blasko from Innsbruck Medical University in Austria wrote that, even with the study’s small number of participants and the need for the findings to be repeated, the study has “important implications”.
‘Tightening the link between omega-3s and B-vitamin metabolism’
It also found a link between B vitamins, omega-3 and homocysteine, an amino acid linked to suspected or confirmed dementia. Tissue and plasma concentrations of homocysteine are known to be determined by vitamin B status, as they are cofactors for enzymes involved in homocysteine metabolism.
Intervention studies with B vitamins have yielded disappointing results in people with MCI or dementia, but the new data suggests that omega-3 status is also vitally important.
“[T]he findings tighten the link between omega-3 fatty acids and B-vitamin metabolism,” wrote Blasko. “The mechanism by which omega -3 fatty acids are thought to exert their protective effect is by stimulating neurite outgrowth and reducing reactive oxygen species production. It appears that a sufficient B-vitamin status and low homocysteine concentrations are required for an optimal utilization and distribution of omega -3 fatty acids.
“Second, these data may improve our understanding in identifying elderly persons who could benefit from supplementation with B vitamins and/or omega-3 fatty acids.
“In this context, it is important to note that the annual conversion rate from MCI to dementia varies between 5% and 10% and most people with MCI will not progress to dementia even after 10 years of follow-up. We still do not know whether higher homocysteine concentrations predict conversion. The double-blind period of the VITACOG trial ended about five years ago and a report on the conversion rates to dementia in this population is eagerly awaited.”
‘An exciting finding’
Commenting on the study’s findings Harry Rice, PhD, VP of regulatory & scientific affairs for the Global Organization for EPA and DHA Omega-3s (GOED), told us: “That brain atrophy rates were lowest in those with the highest plasma omega-3 levels is clearly an exciting finding. Pending confirmatory results, this could lead to nutrition recommendations with a widespread impact on the aging population.
“While the authors alluded to it, they never came out and said it, but the results from this research provide further evidence that we need to be cognizant of a full range of nutrients, not just one.”
Led by Fredrik Jernerén, the researchers performed a retrospective analysis of data from the VITACOG trial of 168 elderly people over the age of 70 who had been randomized to receive either placebo or daily B vitamin supplements (0.8 mg folic acid, 20 mg B6, and 0.5 mg B12, TrioBe Plus; Meda AB/Recip AB) for two years.
Results showed that there was a significant interaction between the supplemental B vitamins and plasma omega-3 (EPA + DHA) levels on brain wasting rates.
The highest average omega-3 levels at the start of the study, defined as greater than 590 micromoles per liter, had a 40% slowed rate of atrophy compared with placebo, said the researchers, but no association was observed for the lowest average omega-3 levels, defined as less than 390 micromoles per liter.
“[W]e have shown that the effect of B vitamin supplementation on brain atrophy rates depends on pre-existing plasma omega-3 fatty acid concentrations; this finding could possibly explain why some B vitamin trials on brain function have failed,” wrote the researchers. “Conversely, our results suggest that homocysteine status may also determine the effects of omega-3 fatty acids in cognitive decline and dementia and so could explain why some trials of omega-3 fatty acids have failed.
“Altogether, our results emphasize the importance of identifying subgroups in clinical trials.”
Source: American Journal of Clinical Nutrition
Volume 102, Number 1, Pages 215-221, doi: 10.3945/ajcn.114.103283
“Brain atrophy in cognitively impaired elderly: the importance of long-chain ω-3 fatty acids and B vitamin status in a randomized controlled trial”
Authors: F. Jernerén, A.K. Elshorbagy, et al.
Editorial: American Journal of Clinical Nutrition
Volume 102, Number 1, Pages 7-8, doi: 10.3945/ajcn.115.114322
“Interaction of ω-3 fatty acids with B vitamins in slowing the progression of brain atrophy: identifying the elderly at risk”
Author: I. Blasko