Eating fish and other foods containing omega-3 fatty acids may lower the risk of Alzheimer's disease.
The oily compounds, which combat inflammation, appear to lower blood levels of a protein linked to Alzheimer's, scientists have found.
Researchers in the US studied 1219 people over the age of 65 who were free of dementia.
Participants were asked questions about their diet, and had their blood tested for beta-amyloid.
The protein clumps together in the brains of people with Alzheimer's and is one of the hallmarks of the disease.
Blood beta-amyloid levels were found to lower with greater consumption of omega-3 fatty acid.
A daily intake of one gram of omega-3 above the average amount consumed by the study participants was associated with a 20% to 30% reduction in beta-amyloid.
Scientists believe the levels of the protein in the blood reflect those found in the brain, indicating a protective effect caused by consuming foods rich in omega-3.
Dr Nikolaos Scarmeas, from Columbia University Medical Centre in New York, said: "While it's not easy to measure the level of beta-amyloid deposits in the brain in this type of study, it is relatively easy to measure the levels of beta-amyloid in the blood, which, to a certain degree, relates to the level in the brain.
"Determining through further research whether omega-3 fatty acids or other nutrients relate to spinal fluid or brain beta-amyloid levels, or levels of other Alzheimer's disease-related proteins, can strengthen our confidence on beneficial effects of parts of our diet in preventing dementia."
The scientists, whose findings are reported in the journal Neurology, looked at 10 nutrients including saturated fatty acids, omega-3 and omega-6 fatty acids, mono-unsaturated fatty acid, vitamins E, C, B12 and D, folate and beta-carotene.
The link between omega-3 and blood beta-amyloid remained the same after adjusting for a range of potential influences, including possession of a version of the APOE gene known to increase Alzheimer's risk.
Omega-3 fatty acids are mostly found in oily fish such as salmon, herring and mackerel. Lower amounts can also be found in nuts, Brussels sprouts, kale and spinach, and vegetable oils.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article