There are many forms of Omega-3 like ALA, DHA, EPA. ALA is the precursor omega-3, which will be converted to EPA or DHA depending on body's need. However, human conversion of ALA to DHA/ EPA is very inefficient, making it less of a good source of EPA/ DHA. Taking EPA/ DHA directly is usually more efficient.

But, the richest source of EPA/ DHA is deep sea fish. and risk of heavy metal pollution is definitely greater than plant source like flax. Better choose for reliable brand if choose for fish oil, molecularly distilled one.

Effectiveness wise, i think infant/ toddler should be given EPA/ DHA rather than ALA (flax). There are breast cancer patient who take huge amount of flax seed to fight cancer probably because flax contains lignan (not lignin), a substance that appears to be 'phytoestrogenic', though whether flax helps fight breast cancer is still not that conclusive. Some studies even said lignan might cause cancer. The pro and con of flax are mixed. Flaxseed oil should not pose this problem because most of the lignan has been removed when only oil is consumed.

Whichever you choose, just make sure don't overdose. Too much of fish oil will thin the blood, therefore before any major operation/ delivery, should stop consuming 2 weeks to 1 month before that.

This post has been edited by cactuscch: Oct 18 2010, 11:04 PM

flax DOESN'T contain EPA/ DHA !!

Many company mix both flaxseed oil and fish oil (or even borage oil, evening primrose oil). Therefore, the mixture will contain EPA/ DHA. But EPA/ DHA are coming from fish oil, NOT flaxseed/ borage/ evening primrose oil.

If got time, can read below

http://www.webmd.com/heart-disease/news/20...-fish-oil-pills

It's about how flaxseed oil and fish oil help prevent heart problem.

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Added on October 18, 2010, 11:32 pmFlaxseed oil contains mostly omega-3, little omega-6, but I'm not sure whether it has omega-9. I refer to this link http://nutritiondata.self.com/facts/fats-and-oils/7554/2 but can't see any omega-9.

This post has been edited by cactuscch: Oct 18 2010, 11:32 PM

in theory, omega-3 & omega-6 are essential fatty acid, where our body cannot manufacture. We can manufacture omega-9, therefore it's not that essential.

in practical, our daily diet has too much of omega-6. The right way is to take more omega-3 and lessen omega-6, especially if our diet is more westernized.

"The typical American diet has a ratio of around 20 to 1 -- 20 omega-6's to 1 omega-3 -- and that spells trouble," says Sandon, an assistant professor of nutrition at University of Texas Southwestern Medical Center in Dallas. While reducing your intake of omega-6s can help, getting more omega-3s from food is an even better way to go.
Full article taken from here: http://www.webmd.com/diet/guide/good-fat-b...s-about-omega-3