Fish oil

Consuming fish at least once a week was associated with a 10 percent per year slower rate of cognitive decline in elderly people, according to a new study posted online today from Archives of Neurology, one of the JAMA/Archives journals. The study will be published in the December print edition of the journal.

Fish is a direct source of omega-3 fatty acids, which have been shown to be essential for neurocognitive development and normal brain functioning, according to background information in the article. Fish consumption has been associated with lower risk of dementia and stroke and recent studies have suggested that consumption of one omega-3 fatty acid in particular, docosahexaenoic acid (DHA), is important for memory performance in aged animals.

Louisiana State University scientists say they have discovered how the fatty acids found in fish oil help protect the human brain from the type of cognitive decline associated with Alzheimer's disease.

Their study shows that docosahexaenoic acid (DHA), an omega-3 fatty acid found in coldwater fish such as mackerel, sardines and salmon, reduces levels of a protein known to cause damaging plaques in the brains of Alzheimer's patients.

What's more, the researchers discovered that a derivative of DHA, which they dubbed "neuroprotectin D1" (NPD1), is made in the human brain. That natural substance plays a key role, too, in protecting the brain from cell death, the study showed.

"Now what does this tell us from the point of view of the disease? I believe that, obviously, diet is a major issue here," said Dr. Nicolas G. Bazan, director of the Neuroscience Center of Excellence at the Louisiana State University Health Sciences Center in New Orleans.