Can You Take Flax Seed Oil as a Substitute for Fish Oil?
Many people, including doctors, tout flax seed oil as a substitute for fish oil. Some studies, however, indicate that flax seed oil may not be as reliable as fish oil as a source for those important omega-3 fatty acids.
Flax seed is universally accepted as the best vegetarian source of anti-inflammatory omega-3 fatty acids, and research has shown that the flax seed’s unique nutritional profile can help regulate hormones, improve skin health and even protect against heart disease. Flax seeds are particularly rich in a short-chain omega-3 fatty acid called ALA (alpha linolenic acid). But calling flax a “substitute” may be a stretch.
The reason: Flax seed oil provides short-chain ALA, some of which the body converts into the long-chain omega-3 fatty acids EPA and DHA, like those preformed in fish oil.
Some new tests show that the body’s ability to perform this conversion may vary from person to person. The rate of conversion may be paricularly inefficient in some individuals, especially for DHA (docosahexaenoic acid), which is essential for brain development in infants and brain protection during aging. For example:
- Taking high daily doses of flax seed oil (3,000 mg alpha linolenic acid) caused no increase of omega-3 DHA in the blood of subjects, finds a new Emory University study. Flax seed oil did, however, result in a synthesis of some EPA (eicosapentaenoic acid), the other important omega-3 fatty acid in fish oil.
- Similarly, researchers at the National Institutes of Health find that feeding animals alpha linolenic acid, as found in flax seed oil, did not increase DHA in brain cells.
- British researchers found that flax seed oil is a “limited source” of long-chain omega-3 fatty acids, especially in men, who are less apt than women to convert flax seed oil to EPA or DHA.
Bottom Line: If you want to be sure you get the benefits of both short- and long-chain omega-3s, your best bet is to incorportate both flax seeds or flax seed oil AND fatty fish and/or fish oil supplements into your daily routine.
Sources: Harper CR., J Nutr2006 Jan; 136(1): 83-7. Demar, JC Jr., J Neurochem 2005 (4): 1063-76; Francois, CA, Am J Clin Nutr 2003;78(4):806.