Cape Town - Omega-3 fatty acids boost the ability of B vitamins to slow mental decline and the onset of conditions like dementia, a new study has found.
The team from UCT, Oxford and the United Arab Emirates (UAE) studied more than 250 people with mild cognitive impairment (MCI) in Oxford over two years. 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.
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. Their cognitive performance was measured and the results compared with their initial results.
UAE University Institute of Public Health Assistant Professor 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.”
Alzheimer’s Society research and development director Doug Brown 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.”
He said the relationship between nutrition and brain health is complex and increased research needed to be done to understand the role that diet and nutrition can play in reducing a person’s risk of dementia.
Professor David Smith, of Oxford University, said the next stage would 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.”