top of page
  • Writer's pictureDr. Sarah Penney, ND, MSc

Which Omega Fat Should You Avoid In Supplements?

Updated: Feb 10, 2020

I work quite a bit with nutritional supplements as a Naturopathic Doctor, and patients are very interested to know what they should be taking. Health information about supplements is often confusing and conflicting, and many people spend hundreds of dollars a month on supplements they hear about in the media but may not be right for them. One supplement in particula that patients often come to my office taking is combination of three omega fats: 3, 6 and 9. While all of these oils are important to our health, we may not need them all in supplement form. Many patients appreciate this information when investing in a pricey omega supplement.

Omega 3

When it comes to taking any oil supplement, a pure omega 3 product is my top choice. Omega 3 fatty acids are found in several different food sources, but the main source found in combination supplements like our 3:6:9 is from fish. Recent research has clearly shown that omega 3 can benefit our health in many ways including proper growth and development, maintenance of brain health, management of inflammation and these fatty acids may even decrease our risk of heart disease. The American Heart association recommends 2 fatty fish meals per week (salmon, trout, mackerel) to get a therapeutic dose of omega 3 fatty acids from diet. (1,2)

Worried about increasing your fish intake? I have heard many valid concerns about increased exposure to heavy metals and toxins through fish, sustainability of fisheries and environmental impact of buying fish. Large fish are often those with the highest amount of omega 3 fatty acids, but they are also subject to a process called bioaccumulation. This means that the contaminants like heavy metals can build up in their tissues from consuming multiple source through small fish and crustaceans. If you do choose to eat fish, I recommend having a look at a fisheries guide to find out what fish to avoid that might be highest in these contaminants and when fresh or farmed is best. A few of the top 3 fish to avoid due to a high mercury content include Chilean Seabass, Yellowfin Tuna and some types of Atlantic Salmon. A wallet sized guide from a Canadian based organization called Seachoice focusing on sustainable and safe seafood consumption can be found here:…/SC_card_2011_web.pdf

One simple choice you can make what it comes to fish is choosing the right type of canned tuna, and I am not talking about the sundried tomato! The types of canned tuna you will find are albicore, slipjack, yellowfin and tongol. Out of these fish the albicore tuna is the one with the highest amount of mercury. Read the label on your cans and choose slipjack tuna when you can. (3)

A conundrum you could face when selecting an Omega 3 natural health product may be deciding what source of omega 3 oils is best. Many nut and seed based products boast benefits by advertizing their omega 3 content, but we may not be able to use the FORM of omega 3 found in these foods (ALA) as well as the form found in fish oils (EPA and DHA). This is because our body needs to convert ALA into EPA for use via the enzyme delta-6-destaturase, while no conversion is needed when we consume sources of EPA. (4) The most common seed oil that claims to offer these benefits is flax oil. Although flax oil may have other health benefits, generally if a patient is looking to decrease inflammation or promote general health by increasing their intake of omega 3 fats, I recommend fish oils or a vegan sourced EPA and DHA supplement whenever possible.

Omega 6

This middle child in our triad of omega oils is the one I recommend avoiding in your supplements. Omega 6 fats are found in safflower, sunflower, corn, soybean and other oils which we tend to consume in high amounts through our packaged and processed foods. Although natural medicine has discouraged intake of omega 6 oils for quite some time, recent evidence supports the conclusion that high levels of omega 6 can promote inflammation (5). This could be a result of the increase in an inflammatory precursor called arachadonic acid in the body which may play a role in a variety of chronic disease outcomes. While a small amount of omega 6 is of course important for our health, the majority of us get more than enough through our diet and do not need an additional supply through supplementation.

Omega 9

Do you know where this fat comes from? Not many people do, although it is also a health promoting fat that we should try to incorporate in our diet. The best dietary source of omega 9 fats is olive oil, which is perfect as a salad dressings mixed with balsamic vinegar, drizzled on a sandwich instead of mayonnaise, or even added to a smoothie. Interest in health benefits of olive oil were spurred while studying the Mediterranean Diet, and it has since been shown to possibly help control cholesterol levels, manage blood sugar levels, and regulate blood clotting (6).

When it comes to increasing your intake of olive oil it is best to try and consume a raw form, meaning it is prepared away from heat. Although opinions vary, exposing olive oil to extreme heat may damage the sensitive Omega 9 fats and destroy antioxidants called phenols (7,8). I recommend only using olive oil when cooking under about medium heat, and using more stable oils like coconut oil when the heat is higher. In addition, only purchase olive oil that is cold pressed, meaning that it has not been exposed to heat during production.

Article originally written by Dr. Sarah Penney, ND, MSc for ACE nutritions - availbe here:


1. N.A. 2011. University of Maryland Medical Center: Omega-3 Fatty Acids. Retrieved July 8, 2013. Available at

2. Krauss RM et al. AHA Scientific Statement: AHA Dietary guidelines Revision 2000: A statement for healthcare professionals from the nutrition committee of the American Heart Association. Circulation. 2000;102(18):2284-2299.

3. N.A. 2008. Health Canada: Mercury in Fish. Retrieved July 8, 2013. Available at

4. Horrobin, DF. Fatty acid metabolism in health and disease: the role of delta-6-desaturase. American Journal of Clinical Nutrition. 1993; 57(5): 732S-736S

5. Patterson et al. Health implications of high dietary omega-6 polyunsaturated fatty acids. Journal of Nutrition and Metabolism. 2012;2012: 1-16

6. Hensrud, D. 2011. Mayo Clinic: If olive oil is a fat, why is it considered healthy? Retrieved July 8, 2013. Available at

7. Allouche Y et al. How heating affects extra virgin olive oil. Journal of Agricultural Food Chemistry. 2007;55(23): 9646-54

8. Vissers MN et al. Bioavailability and antioxidant effects of olive oil phenols in humans: a review. European Journal of Clinical Nutrition 2004 Jun;58(6):955-65.

- Dr. Sarah Penney, ND, MSc -

84 views0 comments

Recent Posts

See All
  • Instagram
  • c-facebook
  • YouTube


bottom of page