- I like fish, but cold whole dead fish leave me cold
Consumption of omega-4 fatty acids, mainly from fish, is thought to prevent dementia and certain types of heart disease such as heart attacks and dangerous rhythm disturbances. For those who don’t like fish or can’t afford it, would taking omega-3 fatty acid supplements be just as effective?
Unfortunately, supplementation does not help prevent age-related cognitive decline and dementia, according to an article at MedPage Today.
The respected Cochrane organization did a meta-analysis of three pertinent studies done in several countries (Holland, UK, and ?).
The investigators leave open the possibility that longer-term studies—over three years—may show some benefit.
I leave you with a quote from the MedPage Today article:
And while cognitive benefits were not demonstrated in this review, Sydenham and colleagues emphasized that consumption of two servings of fish each week, with one being an oily fish such as salmon or sardines, is widely recommended for overall health benefits.
Consumption of cold-water fatty fish also helps return our dietary omega-6/omega-3 fatty acid ratio toward our ancestral level.
Steve Parker, M.D.
Paleo Diabetic 
My personal experiments show that adding a lot of Omega-3 to the diet is not really
valuable compared to subtracting the vast wasteland of Omega-6 from all the chicken,
vegetable oil, fast food, processed products, endless nuts and peanuts, etc. Whether
my cognition will suffer from this is yet to be determined, and I never see any studies taking this more sensible but less popular approach.
Hey, Jim. William Lands, Ph.D., agrees with you on cutting down on omega-6 FAs: http://advancedmediterranean.com/2012/03/29/what-about-the-omega-6-omega-3-fatty-acid-ratio/
Jim is right, science backs him up. Omega 6 – plus higher-carb diet -abrogates the benefits of EPA and DHA on obesity,
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3609096/
also its protection against macular degeneration.
Thanks for that link, George.