Several media outlets reported last week that Omega-3 fish oil supplements fail to show positive results for Alzheimer's patients, based on the study Docosahexaenoic Acid Supplementation and Cognitive Decline in Alzheimer Disease: A Randomized Trial in JAMA.

The researchers reported that supplementation with DHA compared with placebo did not slow cognitive and functional decline in patients with mild to moderate Alzheimer disease. 

Robert Orr, Chairman of Ocean Nutrition Canada, a fish oil supplement company, noted that fish oil was not used in the study and it clearly stated the research was performed using algal oil , which contains only DHA, whereas fish oil contains both EPA and DHA.   Although DHA is a major component of the brain, he says, it should not be automatically concluded that other fatty acids have no potential role in cognitive performance. 

"It is disappointing to see inaccurate misrepresentation of the facts by the media. As an example, many media outlets are leading with pictures of fish oil capsules," stated Orr. 

Well, what of it?  Fish oil proponents contend that Omega-3 EPA and DHA are required to influence cognitive performance and note that some studies on Alzheimer's and Omega-3 fatty acids with favorable outcomes have involved fish oil or fish consumption. 

 Ocean Nutrition Canada also contends that since the study was conducted in patients with pre-existing Alzheimer's,  improvements are difficult to measure, but that fatty fish consumption and supplementation with fish oil may help maintain a healthy cognitive state. 

EU Health Authorities recently established a Dietary Reference Value (DRV) of 250mg per day of EPA and DHA and it is expected that updated Dietary Guidelines for Americans scheduled to be issued in December will include recommendations for the daily intake of fatty fish equivalent to 250mg EPA plus DHA per day. 

About Omega-3:

 Omega-3 is a family of essential fatty acids (EFA), including EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid), and ALA (alpha-linolenic acid). Oily fish (such as sardines, anchovies, mackerel, and salmon) are the major known natural sources of Omega-3 EPA and DHA. ALA is found in plants, such as flax and chia.   EPA and DHA are the primary contributors of the many health benefits associated with Omega-3. While the body can convert ALA into EPA and DHA, it does so very inefficiently (typically less than one percent), making it difficult to derive Omega-3-related health benefits from plant-sourced ALA.  

The human body is not able to produce sufficient quantities of Omega-3 EPA and DHA on its own, so regular consumption of these essential nutrients is required and achieved by either by eating oily fish or foods fortified with Omega-3 EPA and DHA, or by taking fish oil supplements.