Omega-6 and omega-3 fatty acids are both essential to human health. That’s why they’re called “essential fatty acids.” In general, omega-6s (which are concentrated in vegetable oils) are considered inflammatory, while omega-3s (which are concentrated in fish and flax oils) are not. But the question of what ratio they should be consumed in is controversial.
Some researchers have claimed that our prehistoric ancestors ate only 2-3 times as many omega-6s as omega-, and that our modern ratio of 15:1 to 17:1 means we’re way out of balance. Other experts have claimed there’s no evidence of an ideal ratio at all. Finally, a study has come out that could help settle the debate.
Research conducted on animals published in the Journal of Nutritional Biochemistry last summer tested how different ratios of various omega-6s and omega-3s in the diets of mice affected their heart health. They found a 4:1 ratio was most beneficial.* (In other words, increasing consumption of omega 3 fatty acids so that the ratio of omega 6-to-3 is reduced to only four to one)
They also experimented with different levels of DHA and EPA, two types of omega-3s found in fish and krill, and found that the omega-6 to omega-3 ratio was more important than the ratio of DHA to EPA. However, since DHA seems to help keep LDL (bad) cholesterol in check, and a 1:1 ratio of DHA to EPA seems to help maintain healthy levels of HDL (good) , it’s fair to say both DHA and EPA are important to heart health.*
Because this was an animal study, it needs to be confirmed in human research before it’s conclusive. But it does bolster the case for increasing your intake of omega-3s to make sure you’re getting a healthy ratio of omega-6 to omega-3. (Even though you need more omega-6s than omega-3s, omega-6s are much easier to come by, so it’s easy to go overboard.)
A good strategy is to eat healthy sources of omega-6 fatty acids such as poultry, eggs, almonds, and whole grains (while avoiding unhealthy ones such as most vegetable oils), along with good sources of omega-3s such as fatty fish, seaweed, walnuts, and flax seeds. And to tip the scale toward a better ratio, consider an omega-3 supplement.
* This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, cure, treat, or prevent any disease.
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 Fish oil. Consumer Lab. 2017. https://www.consumerlab.com/tnp.asp?chunkiid=21684
 Liang L, et al. J Nutr Biochem. 2016 Jun;32:171-80.
 Gray N. NUTRAingredients-usa.com. 2016 Oct 10.