I want to take an omega-3 fatty acid supplement, but don’t like the idea of taking fish oil. I know that flax oil contains omega-3s, can I take that instead?
I fully understand aversion to fish oil be it aesthetic or political. The short answer to your question is yes, you can take flax oil for supplemental omega-3s, however it is likely to be less effective than fish oil.
Flax oil contains an omega-3 called alpho-linolenic acid (ALA). Once in our system, the body converts ALA to the longer chain omega-3s EPA (eicosapentanoic acid) and DHA (docosahexanoic acid), which then go on to affect benefits such as reduced inflammation. The argument of many doctors and scientists is that the conversion process of ALA to EPA and DHA is highly inefficient. As a result it may be impossible for your body to produce enough EPA and DHA from flax oil or other plant-based omega-3s to really receive much positive effect.
One factor that seems to increase the inefficiency of ALA conversion is the presence of large amounts of linoleic acid, a common omega-6 found in many plants, in body fat. Since modern diets, both vegetarian and omnivorous, tend to be disproportionately high in omega-6s, this is a concern for nearly everyone. Another factor is elevated insulin which can reduce the amount of ALA converted to be almost negligible.
When finding an appropriate dosage for supplementation, you can consider 3-4 g of ALA to be equivalent to 300 mg of EPA. To compare to 1.5 g of fish oil (a general starting dose containing 210 mg of EPA), you would need 1-1.5 teaspoons of flax oil (3.7-5.5 g containing 2.1 g of ALA), or at least 2.5 times as much.
There are two additional concerns with flax oil that are worth mentioning. First, flax oil goes rancid quickly and should not be consumed once this happens. If you’ve purchased a high-quality, cold pressed flax oil, you can tell its freshness by smell. When it goes bad it has the distinct smell of oil-based paint. Quality flax oil will be found in dark containers and only in refrigeration. At home you should store it in the refrigerator or freezer. Second, a 2004 study of 47,000 men suggest that ALA can stimulate growth of prostate tumors, while EPA and DHA can reduce prostate cancer risk. Ground flax seeds, however may have an inhibitor effect on prostate cancer, possibly due to the fiber and fiber-like components contained in the whole seeds.
If you decide to include flax seed in your diet, use the following guidelines: Purchase whole seeds only, preferably from the refrigerator section of the store. If you can’t find refrigerated flax seeds in your store, the ones on the shelf may still be fine if the store’s turnover is high. The seeds should smell fresh, just like the oil, with no hints of paint odor. Store the seeds whole in your refrigerator or freezer, and grind them (a coffee grinder works great) just before use. Freshly ground flax seeds make a great addition to salads, yogurt, smoothies, juices, peanut butter sandwiches, and many other healthy foods.
Ask the Nutritionist is free service offered by Eat For Change Nutrition Counseling, EFC members get their health and nutrition questions answered personally by our EFC Nutritionist and Founder, Shannon Sullivan . Once signed up, you can use our Ask the Nutritionist form to email you question. You’ll hear back from Shannon within 3 days. Of course, she won’t be able to diagnose your health condition or give specific treatment advise with one simple email. She will share her information and professional opinion to help guide you towards making your most informed health decisions.