Having higher levels of Omega-3 fatty acids in your body can boost the impact of key vitamin B supplements, leading to slow mental decline in older people with memory problems, an international team has found.
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.
"We previously found that B vitamins are able to slow or prevent the atrophy of the brain and memory decline in people with MCI. We wanted to find out whether Omega-3 and B vitamins might interact to prevent cognitive decline," said Dr Celeste de Jager from University of Oxford.
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: DHA and EPA.
"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," explained Dr Abderrahim Oulhaj from Oxford.
"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," he added in a paper published in the Journal of Alzheimer's Disease.
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.
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, the authors noted.
