Raw salmon on a cutting board with fresh spices

    Can oily fish protect the brain from dementia?

    31 May 2017

    ‘Oily fish can beat dementia,’ read the front page of yesterday’s Daily Express. The headline was widely mocked. ‘Great news for oily fish,’ ran the joke on Twitter. ‘What about us human beings?’

    The study, published in the Journal of Alzheimer’s Disease, found that a higher consumption of omega-3 fatty acids — present in high quantities in oily fish — appeared to increase blood flow to areas of the brain linked to ‘learning, memory, depression and dementia’, according to one of the authors.

    The researchers used a neuroimaging technique called single photon emission computed tomography (or SPECT) to measure blood profusion in the brain. The images were made while test subjects performed various cognitive tasks.

    The 166 participants were divided into two groups; those with higher levels of omega-3 (in the 50th percentile or above) and those with lower levels (below the 50th percentile).

    The researchers found a ‘statistically significant’ correlation between increased blood flow and higher levels of omega-3 in the blood.

    William Harris, the study’s co-author, said: ‘Although we have considerable evidence that omega-3 levels are associated with better cardiovascular health, the role of the ‘fish oil’ fatty acids in mental health and brain physiology is just beginning to be explored. This study opens the door to the possibility that relatively simple dietary changes could favourably impact cognitive function.’

    Government guidelines recommend that we eat two portions of fish a week, one of which should be of the oily variety.

    Instant analysis
    This report does seem to add another tiny piece to the huge and evolving jigsaw that is our understanding of this increasingly common and fatal condition. Its incidence is expected to triple in the future and there is currently no cure.

    Although the study does not suggest any treatments, it does raise the possibility that dietary factors could significantly affect cognitive functioning and that omega-3 fatty acids such as are found in oily fish could be one of the key components here. The results were statistically significant, and pave the way for further research into dietary approaches to Alzheimer’s disease.
    Research score: 3/5