Will the real omega-3 please stand up?

When I met her, Phyllis' triglycerides ranged from 200-300 mg/dl, suggesting that it was a factor contributing to her heart disease. Fish oil was the solution of choice, since it is marvelously effective for reducing triglycerides. Her dose: 6000 mg of a standard 1000 mg capsule (6 capsules) to provide 1800 mg EPA + DHA, the effective omega-3 fatty acids. Triglycerides dropped to 77 mg/dl.

But Phyllis is not terribly good at following advice. She likes to wander off and follow her own path. She noticed that the healthy bread sold at the grocery store and containing flaxseed boasted "900 mg of omega-3s per slice!" So she ate two slices of the flaxseed-containing bread per day and dropped the fish oil.

Guess what? Triglycerides promptly rebounded to 290 mg/dl. She also gained 8 lbs. (though we can't blame only the bread, since Phyllis has a terrible sweet tooth.)

A more obvious example of the power of omega-3s occurs in people with a disorder called "familial hypertriglyceridemia," an inherited inability to clear triglycerides from the blood. These people have triglycerides of 400 mg/dl, 700 mg/dl, or higher. Fish oil yields dramatic triglyceride drops of hundreds of milligrams. Fish oil likely achieves this effect by activating the enzyme, lipoprotein lipase, that is responsible for clearing blood triglycerides. Flaxseed oil and other linolenic acid sources yield . .. nothing.

Don't get me wrong: Flaxseed is a great food. As the ground seed, it reduces LDL cholesterol, reduces blood sugar, provides fiber for colon health, and may even yield anti-cancer benefits. Flaxseed oil is a wonderful oil, rich in monounsaturates, low in saturates, and rich in linolenic acid, an oil fraction that may provides heart benefits a la the Mediterranean diet.

But linolenic acid from flaxseed is not the same as EPA + DHA from fish oil. This is most graphically proven by the lack of any triglyceride-reducing effects of flaxseed preparations.

Enjoy your flaxseed oil and ground flaxseed-but don't stop your fish oil because of it. Heart disease and coronary plaque are serious business. You need serious tools to combat and control them. Fish oil is serious business for triglycerides. Flaxseed is not.