Omega-3 fatty acids
Omega-3s are a type of polyunsaturated fatty acid (PUFA). Research has linked certain types of omega-3s to a reduced risk of heart disease and stroke.
The U.S. Food and Drug Administration (FDA) permits supplements and foods to display labels with qualified health claim for two omega-3s called docosahexaneoic acid (DHA) and eicosapentaenoic acid (EPA). The labels may state, “Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease,” and then list the amount of DHA or EPA in the product.
Research has also linked high intake of omega-3s to a possible reduction in risk of dementia or cognitive decline. The chief omega-3 in the brain is DHA, which is found in the fatty membranes that surround nerve cells, especially at the microscopic junctions where cells connect to one another.
Theories about why omega-3s might influence dementia risk include their benefit for the heart and blood vessels; anti-inflammatory effects; and support and protection of nerve cell membranes. There is also preliminary evidence that omega-3s may also be of some benefit in depression and bipolar disorder (manic depression).
A report in the April 2006 Nature described the first direct evidence for how omega-3s might have a helpful effect on nerve cells (neurons). Working with laboratory cell cultures, the researchers found that omega-3s stimulate growth of the branches that connect one cell to another. Rich branching creates a dense neuron forest, which provides the basis of the brain’s capacity to process, store and retrieve information.