One of the key selling points of fish oil is that it contains the omega-3 essential fatty acids docosahexaenoic acid (DHA) and eicosahexaenoic acid (EPA), and flaxseed oil capsules do not. That's absolutely true, although the human body can use flaxseed oil capsules to make its own DHA and EPA.
Flaxseed oil is less expensive than fish oil, and its manufacture involves less shipping, refining, and invasion of animal habitat. And if you are vegan or vegetarian, there is simply no question that you would prefer to buy flaxseed oil products. (There are, by the way, no flaxseed oil pills, just capsules and the bottled oil.)
Moreover, if you want to get the cancer-fighting benefits of high-lignan flaxseed oil, you simply have to use a liquid flaxseed oil product, whether with your food or in capsules. But whether you should ditch the fish oil right now and go for flaxseed oil depends on some important individual differences.
- Different people need different amounts of flaxseed oil.
- Women need less flaxseed oil than men to produce the same amount of DHA and EPA.
- Think tablespoons of flaxseed oil to compare to capsules of fish oil. How much flaxseed oil does it take to equal fish oil? The best example is a product called Udo's Choice, containing flaxseed oil, which is about 50% ALA.
The human body can use up to about 20 per cent of the alpha-linolenic acid, also known as ALA, in flaxseed oil, to make the omega-3 essential fatty acids DHA and EPA. It just can't use all the ALA in flaxseed oil to make DHA and EPA.
Some of the older studies found that only about 5 per cent of the ALA in flaxseed oil becomes DHA and EPA. That would seem to suggest that if you want to get the equivalent of one capsule of fish oil, you'd need to take about six capsules of flaxseed oil.
New studies find that up to 36 per cent of the ALA in flaxseed oil becomes DHA and EPA, but that the conversion rate depends on having enough magnesium, zinc, and B vitamins, and that the conversion rate is lower the more sugar there is in the diet. This means that if you don't get your magnesium, zinc, and the various forms of vitamin B, you need more flaxseed oil.
Men need about twice as much flaxseed oil as women.
The bodies of younger women who take birth control pills that are higher in estrogen than progesterone are especially efficient at converting ALA to DHA and EPA. The bodies of older men who like to eat Snickerdoodles are especially inefficient at converting ALA to DHA and EPA. The average of studies is about a 20 per cent ratio for all women and a 10 per cent ratio for all men. Men need about twice as much flaxseed oil as women.
A woman who weighs 100 pounds (45-46 kilos) who takes 2 tablespoons (30 grams) of Udo's Choice Oil Blend gets about 14,000 mg of ALA a day. Her body turns part of this ALA into 5,000 mg of DHA, EPA, and another omega-3 fatty acid called DPA. That's about the equivalent of taking 17 capsules of high-quality fish oil or 35 capsules of the kind you get at WalMart.
A man who weighs 150 pounds (67-68 kilos) and who takes 3 tablespoons (45 grams) of Udo's Choice Oil Blend ends up with about 3,360 mg of DHA, EPA, and DPA every day. That's the equivalent of taking 11 capsules of high-quality fish oil or 22 capsules of low-grade fish oil.
It's a lot easier to add a tablespoon of flaxseed oil into salad dressings or smoothies or cereals than it is to down 30 capsules of fish oil. And if you are taking low-quality fish oil, that many capsules runs a risk of a bad case of "fishy burps."
Moreover, you don't have to worry about ocean-born toxins and pollution, and your body keeps you from overdosing on DHA-which can happen if you take fish oil in addition to an otherwise purely vegan, zero-fat diet, such as the new versions of Dr. Dean Ornish's diet.
Flaxseed oil is cheaper and it works. And if you don't want to bother with adding flaxseed oil to your food, then flaxseed oil capsules may be just what you need.
Read more about flaxseed oil vs fish oil.
- British Journal of Nutrition 2002 Oct;88(4):411-20. Conversion of alpha-linolenic acid to eicosapentaenoic, docosapentaenoic and docosahexaenoic acids in young women. Burdge GC, Wootton SA. Institute of Human Nutrition, University of Southampton, Southampton, UK.
- British Journal of Nutrition 2002 Oct;88(4):355-63 Eicosapentaenoic and docosapentaenoic acids are the principal products of alpha-linolenic acid metabolism in young men. Burdge GC, Jones AE, Wootton SA. Institute of Human Nutrition, Level C, West Wing, Southampton General Hospital, Tremona Road, Southampton, SO16 6YD, UK.