While research has already established that B vitamin supplements can help slow mental decline in older people with memory problems, an international team have now found that having higher levels of Omega-3 fatty acids in your body could boost the B vitamins’ effect.
The team, from the Universities of Cape Town, Oslo, Oxford and the UAE, studied more than 250 people with mild cognitive impairment (MCI) in Oxford. MCI is when brain function is below what is normally expected for a person’s age but is not significant enough to interfere with daily life. While it is not as serious as dementia, if untreated it often progresses to become dementia.
Dr Celeste de Jager said: ‘We previously found that B vitamins are able to slow or prevent the atrophy of the brain and memory decline in people with MCI. This was most effective in those who had above average blood levels of homocysteine, a factor related to B vitamin status that may be toxic to the brain. Scientists in our team initially found that there was a link between Omega-3 levels, homocysteine, and brain atrophy rates. We wanted to find out whether Omega-3 and B vitamins might interact to prevent cognitive decline.’
At the start of the study, each person was given a set of tests to measure their cognition, and had a blood test to determine the levels of two Omega-3 fatty acids commonly found in oily fish: docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
The participants were split into two randomly-selected groups, who received either a B-vitamin supplement or a placebo pill over two years. Their cognitive performance was also measured and the results compared with the baseline results from the start of the study.
Dr Abderrahim Oulhaj said: ‘We found that for people with low levels of Omega-3, the vitamin supplements had little to no effect. But for those with high baseline Omega-3 levels, the B vitamins were very effective in preventing cognitive decline compared to the placebo. This result complements our previous finding that B vitamins slow the rate of brain atrophy in MCI only in those with a good Omega-3 level to start with.’
The team also found that levels of DHA might be more important than levels of EPA, although they caution that more research must be done to establish whether this is true.
Professor David Smith said: ‘The next stage will be to see whether providing a combination of B vitamins and Omega-3 supplements can slow the conversion from MCI to Alzheimer’s disease. This would be an important step in the prevention of Alzheimer’s disease. We have high hopes that this trial would work but funding is not easy to obtain for such studies.’
Dr Doug Brown, Director of Research and Development at Alzheimer’s Society said: ‘These results help us to tease apart who could benefit from taking B vitamins, suggesting that they might only improve cognition in people who have high levels of Omega-3 oils in their blood. Encouragingly, these findings suggest that for some older people a combination of fish oil supplements and B vitamins may help to improve thinking and memory.
‘As this study shows, the relationship between nutrition and brain health is complex and we need to see increased research efforts to help us understand the role that diet and nutrition can play in reducing a person’s risk of dementia.’
About this neurology research
Source:Oxford University Image Credit: The image is adapted from the Oxford University press release Original Research:Abstract for “Omega-3 Fatty Acid Status Enhances the Prevention of Cognitive Decline by B Vitamins in Mild Cognitive Impairment” by Oulhaj, Abderrahima; Jernerén, Fredrik; Refsum, Helga; David Smith, A.; and de Jager, Celeste A. in Journal of Alzheimer’s Disease. Published online January 6 2016 doi:10.3233/JAD-150777
Omega-3 Fatty Acid Status Enhances the Prevention of Cognitive Decline by B Vitamins in Mild Cognitive Impairment
A randomized trial (VITACOG) in people with mild cognitive impairment (MCI) found that B vitamin treatment to lower homocysteine slowed the rate of cognitive and clinical decline. We have used data from this trial to see whether baseline omega-3 fatty acid status interacts with the effects of B vitamin treatment. 266 participants with MCI aged ≥70 years were randomized to B vitamins (folic acid, vitamins B6 and B12) or placebo for 2 years. Baseline cognitive test performance, clinical dementia rating (CDR) scale, and plasma concentrations of total homocysteine, total docosahexaenoic and eicosapentaenoic acids (omega-3 fatty acids) were measured. Final scores for verbal delayed recall, global cognition, and CDR sum-of-boxes were better in the B vitamin-treated group according to increasing baseline concentrations of omega-3 fatty acids, whereas scores in the placebo group were similar across these concentrations. Among those with good omega-3 status, 33% of those on B vitamin treatment had global CDR scores >0 compared with 59% among those on placebo. For all three outcome measures, higher concentrations of docosahexaenoic acid alone significantly enhanced the cognitive effects of B vitamins, while eicosapentaenoic acid appeared less effective. When omega-3 fatty acid concentrations are low, B vitamin treatment has no effect on cognitive decline in MCI, but when omega-3 levels are in the upper normal range, B vitamins interact to slow cognitive decline. A clinical trial of B vitamins combined with omega-3 fatty acids is needed to see whether it is possible to slow the conversion from MCI to AD.
“Omega-3 Fatty Acid Status Enhances the Prevention of Cognitive Decline by B Vitamins in Mild Cognitive Impairment” by Oulhaj, Abderrahima; Jernerén, Fredrik; Refsum, Helga; David Smith, A.; and de Jager, Celeste A. in Journal of Alzheimer’s Disease. Published online January 6 2016 doi:10.3233/JAD-150777