It's known that people who get plenty of DHA, a fish oil fatty acid, have a reduced risk of Alzheimer's disease, note Greg M. Cole, PhD, associate director of the UCLA Alzheimer's Disease Research Center, and colleagues.
Why? Cole's team had a clue. People with Alzheimer's disease tend to have low levels of a brain protein called LR11 (also known as SorLA). And about 15% of people with Alzheimer's disease carry a genetic mutation that reduces LR11.
Sure enough, in live rodents and in cultures of human brain cells, the researchers found that the fish-oil compound DHA causes brain cells to make lots more LR11.
"Because reduced LR11 is known to increase beta amyloid production and may be a significant genetic cause of late-onset Alzheimer's disease, our results indicate that DHA increases in LR11 levels may play an important role in preventing late-onset Alzheimer's disease," Cole and colleagues conclude.
It may be too late for people with late-stage Alzheimer's disease to get much benefit from fish oil. But Cole suggests that it may be a great help if taken at the first signs of Alzheimer's.
Cole and colleagues report their findings in the Dec. 26 issue of The Journal of Neuroscience.