Scientists found a link between raised levels of the omega-6 fatty acid arachidonic acid and memory loss and behavioural changes in mice.
The discovery points to new strategies for tackling Alzheimer's.
Fatty acids are rapidly taken up by the brain and incorporated into phospholipids, a fatty product that forms the membranous "blood-brain" barrier which shields neurons from toxins.
Researchers compared many different fatty acids in the brains of normal mice and animals with a condition that mimics human Alzheimer's disease as part of the research.
Study leader Dr. Rene Sanches-Mejia, from the Gladstone Institute of Neurological Diseases (GIND) in San Francisco, California, said, "The most striking change we discovered in the Alzheimer mice was an increase in arachidonic acid and related metabolites in the hippocampus, a memory center that is affected early and severely by Alzheimer's disease."
Arachidonic acid is released from phospholipids in the brain by an enzyme called group IVA phospholipase, or PLA2.
By lowering levels of PLA2 in Alzheimer's mice using genetic engineering, the memory deficits and behavioural abnormalities associated with the disease were prevented.
From the October 27, 2008, Prepared Foods e-Flash