What is the difference between flax and fish oil?

Kat Barefield, MS, RD
Nutrition & Dietetics
Fish oil from fatty fish contains higher amounts omega-3 fatty acids such as EPA and DHA, the 2 fish oils that provide health benefits. Flaxseed oil comes from the flax plant and contains both omega-3 and omega-6 fats. Flaxseed oil contains the plant derived omega-3 fatty acid alpha-linolenic acid (ALA), which can be converted to EPA & DHA but very inefficiently (8-20% of ALA to EPA; .5-9% to DHA). Therefore, ALA is not considered a good source of the 2 potentially beneficial fish oils EPA and DHA.

The other problem with flaxseed oil is that it contains high amounts of omega-6 fatty acids (FA) which competes with the benefits of omega-3s, meaning omega-6 FA tend to increase harmful inflammation, while omega-3s tends to lower it. Unfortunately the typical American diet contains approximately 15-25 times more omega-6 FA than omega-3.

Ideally, omega-3 intake should be 2-4 times HIGHER than omega-6 intake. Many scientists believe this unbalanced ratio to be a contributing factor to the rise in inflammatory disorders (cardiovascular disease, arthritis, etc.) in the US.

With that said, flaxseed oil may have other unique health benefits when consumed in the correct quantities but if you are looking for the specific benefits, such as maintaining heart, brain, hearing and vision health attributed to omega-3s, stick with fish oil as the source.

Continue Learning about Dietary Supplements

Dietary Supplements

Whether you're visiting the drug store, grocery or natural food shop you'll likely find an aisle where there are jars and bottles of things for you to put in your body that are neither foods nor medicines. Ranging from vitamins an...

d minerals to fiber and herbal remedies, these supplements are not regulated in the same way as either food or medicine. Some of them are backed by solid research, others are folk remedies or proprietary cures. If your diet does not include enough of certain vitamins or minerals, a supplement may be a good idea. Natural treatment for conditions like constipation may be effective. But because these substances are unregulated, it is always a good idea to educate yourself about the products and to use common sense when taking them. This is even more true if you are pregnant or taking a medicine that may be affected by supplements.

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.