Omega-3 intake in midlife has been linked to a better brain structure and reduced risk of dementia in a new US study led by researchers at the University of Texas Health Science Center.
The study, which was published in the Journal of Neurology, involved the analysis of over 2,000 people with an average age of 46 who did not have dementia or stroke.
Blood samples were taken from the volunteers to measure the levels of omega-3 fatty acid concentrations, as well as brain scans to measure the volume of the hippocampus – a region of the brain that plays an important role in memory and thinking.
The researchers found that people who had higher levels of omega-3 fatty acids had higher scores on a cognitive test, and those with a higher omega-3 index also had a larger hippocampus.
“Studies have looked at this association in older populations. The new contribution here is that, even at younger ages, if you have a diet that includes some omega-3 fatty acids, you are already protecting your brain for most of the indicators of brain ageing that we see at middle age,” said Claudia Satizabal, assistant professor of population health sciences with the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases at UT Health San Antonio and lead author of the study.
The effect of omega-3 red blood cell concentrations in volunteers who carried APOE4, a genetic variation linked to higher risk of Alzheimer’s disease, was also studied by the researchers, who found that APOE4 carriers with a higher omega-3 index had less small-vessel disease.
Commenting on the findings of the study, Dr Sara Imarisio, head of research at Alzheimer’s Research UK, said: “In this study, scientists looked at omega-3 fatty acid levels in the blood of people who did not have dementia, finding higher levels were more common in those with better brain structures. Of course, this doesn’t prove that high omega-3 is the reason for the differences in the scans.
“Research into omega-3 and brain health has produced mixed results, and while this study adds to the evidence base, it is exploratory and not conclusive. And because it only looked at people in middle age, this study only offers a snapshot of the full story – it did not look to see whether people went on to develop conditions like dementia.”