This question comes up so frequently that it's worth going over.
Flaxseed oil is a wonderful oil rich in linolenic acid, which may provide health benefits all by itself. Some authorities have speculated that the substantial reduction in heart attack seen in the Lyon Heart Study, the study that demonstrated the healthy power of the Mediterranean diet, is due to linolenic acid.
Flaxseed oil is also rich in monounsaturates and low in saturates, both desirable qualities. Of course, I'm talking here about flaxseed oil, to be distinguished from flax seed, which are the intact seeds. The seeds themselves also contain the same oils, but contain other components, specifically lignan, a plant fiber with suspected health benefits like reduction in cancer risk.
Despite all flaxseed oil's wonderful properties, it is definitely not a substitute for fish oil. Why do we use fish oil for our coronary plaque control program (trying to reduce your heart scan score)? Several reasons. Fish oil:
--Dramatically reduces triglycerides, usually by 50% or more. --Dramatically reduces specific lipoprotein classes like VLDL --Dramatatically reduces, often eliminates, abnormal postprandial (after-eating) lipoprotein patterns, like IDL (intermediate-density lipoprotein) --Has been conclusively shown to reduce risk of heart attack and death from heart attack (GISSI Prevenzione Trial). --Has been shwon to reduce risk of stroke. --Modifies blood clotting parameters, particularly a 20% reduction in fibrinogen.
Flaxseed oil, or linolenic acid concentrate for that matter, do not accomplish any of these effects, all crucial if you are to gain control over your coronary plaque.
Flaxseed oil and flaxseed remain wonderful nutritional agents for their own reasons. But they will not substitute for fish oil in your program. Only fish oil--the real thing--does the job.