Fish Oil Supports Cognitive Function

A recently published study investigated the effect of an omega-3 fatty acid on memory and dysfunction related to Alzheimer’s disease, the most common type of dementia that affects approximately 5.3 million American adults. Previous research has shown that inflammation and the accumulation of proteins known as tau and beta-amyloid play a role in the development of this disease. In addition, there is deterioration of the neurons that secrete the neurotransmitter acetylcholine, which is essential for processing memory and learning.

In this new study, rats were treated with the pro-inflammatory cytokine (cell signaling molecule) interleukin (IL)-1 beta to induce inflammation and memory deficits similar to Alzheimer’s disease. The rats were then supplemented with an omega-3 fatty acid ethyl-eicosapentaenoate (E-EPA) or palm oil as the control. The rats were evaluated for acetylcholine levels; levels of nerve growth factor, which is required for nerve growth and survival; and the effect of glucocorticoids, which are steroid hormones that suppress inflammation.

The study showed that administration of the pro-inflammatory cytokine IL-1beta significantly reduced acetylcholine secretion. The reduction of acetylcholine was able to be reversed with administration of mifepristone, a synthetic steroid pharmaceutical. Using maze tests, the researchers showed that the rats with decreased acetylcholine release had significant memory deficits. Additionally, the rats that received IL-1beta had decreased levels of nerve growth factor expression compared to healthy rats.

The study also showed that treatment of the rats with E-EPA significantly improved memory. Furthermore, E-EPA administration normalized acetylcholine release, nerve growth factor expression, and IL-1beta levels.

The study authors concluded, “This study revealed important mechanisms by which IL-1beta impairs, while E-EPA improves memory through IL-1-glucocorticoid-acetylcholine release and IL-1-nerve growth factor-acetylcholine- release pathways.”

Reference:

Taepavarapruk P, Song C. Reductions of acetylcholine release and nerve growth factor expression are correlated with memory impairment induced by interleukin-1beta administrations: effects of omega-3 fatty acid EPA treatment. J Neurochem. 2010 Feb 1;112(4):1054-64.