By now, you’ve probably heard of polyunsaturated fatty acids (PUFAs) and their importance to human health. As defined by the American Heart Association, polyunsaturated fats are simply fat molecules that have more than one unsaturated carbon bond in the molecule. They can help reduce bad cholesterol levels in the blood, which can lower the risk of heart disease and stroke. They also provide nutrients to help develop and maintain the body’s cells.1
Additionally, oils rich in polyunsaturated fats contribute the antioxidant vitamin E to the diet and provide “essential” fats that your body needs but can’t produce itself: linoleic acid (LA), an Omega 6 fatty acid, and alpha-linoleic acid (ALA), an Omega 3 fatty acid. Studies have shown that balancing Omega 6 and Omega 3 fatty acids is critical because too much of either can impair how the other functions. In other words, like we’ve been told often about diet and exercise, you can have “too much of a good thing.”
In the context of human health, here are two important things to know about Omega 6 and Omega 3 fatty acids2:
- Omega 6 and Omega 3 fats each carry out essential tasks in the body and have different biological roles.
- Omega 6 fats are believed to have a mostly pro-inflammatory effect, whereas Omega 3 fats seem to elicit anti-inflammatory actions.
The American Heart Association states, “polyunsaturated fats can have a beneficial effect on your heart when eaten in moderation and when used to replace saturated fat and trans fat in your diet.”1
Omega 6 / Omega 3 Ratio from a Historical Perspective
Studies indicate that over decades and centuries, major changes in the type and amount of EFA intake and in the antioxidant content of foods in our diets have occurred. Compared to the diet on which humans evolved, current Western diets are deficient in Omega 3 fatty acids and contain excessive amounts of Omega 6 fatty acids. Studies at the molecular level, as well as anthropological and epidemiological studies, indicate that human beings evolved on a diet with a ratio of Omega 6 to Omega 3 EFA of ~1:1, whereas in Western diets today the ratio is 15 : 1 to 16.7 : 1.3
To understand how this ratio became increasingly unbalanced over time, it’s important to consider the evolution of the human diet. Historically, humans were hunter-gatherers and primarily consumed roots, tubers, berries and meat. Once humans learned to grow crops, they stayed in one place and didn’t travel with the seasons. This change to a crop-based diet gradually changed dietary habits. In the last 150 years, especially, human diets have changed due to industrialized agricultural practices.
Also keep in mind that the technology to process seed and vegetable oils with high levels of Omega 6 fatty acids didn’t exist until about 100 years ago. Our bodies are not prepared to consume the high amounts of Omega 6 fatty acids found in today’s industrial food supply.3
Excessive amounts of Omega 6 PUFAs and a very high Omega 6 / Omega 3 ratio promote development of diseases including cardiovascular disease, cancer and inflammatory and autoimmune diseases. On the other hand, increased levels of Omega 3 and and a low Omega 6 / Omega 3 ratio exert suppressive effects on inflammatory responses and auto-immune system diseases.4
How important is managing your Omega 6 to Omega 3 ratio? One study showed that in the secondary prevention of cardiovascular disease, a ratio of Omega 6 / Omega 3 of 4:1 was associated with a 70% decrease in total mortality. The same ratio of Omega 6 / Omega 3 of 4:1 appeared to be the optimal ratio for brain-mediated functions. It is important to keep in mind, however, that studies indicate that the optimal ratio may vary with the disease or condition under consideration.5
Finding Your Omega 6 / Omega 3 Balance
What is the most important thing you can do to reduce your Omega 6 intake? Avoid processed seed and vegetable oils that are high in Omega 6 fatty acids, as well as processed foods high in Omega 6 fatty acids.4
As the chart below shows, some of the biggest sources of Omega 6 fatty acids are sunflower oil, corn oil, soybean oil, and cottonseed oil, while other fats and oils like butter, coconut oil, lard, palm oil and olive oil are all relatively low in Omega 6 fatty acids.
Image Courtesy POS Pilot Plant Corporation
Notably absent from this list was hemp-seed oil, perhaps because it’s not conducive to the discussion about extremes. In fact, hemp-seed oil stands out for delivering the ideal balance of Omega 6 to Omega 3 fatty acids at a ratio of approximately 3:1.
And when considering which protein-rich plant-based foods to add to your diet, consider choosing foods like hemp seeds and hemp-seed derived ingredients, which offer a healthier balance of Omega 6 and Omega 3, as well as a range of other nutritional benefits.
Want to learn even more about the Omega 6 / Omega 3 fatty acid ratio? Below are some additional resources:
- American Heart Association. Polyunsaturated Fats. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/polyunsaturated-fats
- Jacob Aglaée. Balancing act. Today’s Dietician. April 2013 Issue.
- Simopoulos AP. Evolutionary aspects of diet, the omega-6/omega-3 ratio and genetic variation: nutritional implications for chronic diseases. https://doi.org/10.1016/j.biopha.2006.07.080
- Gunnars Kris. How to Optimize Your Omega-6 to Omega-3 Ratio. Healthline. June 2018. https://www.healthline.com/nutrition/optimize-omega-6-omega-3-ratio
- Simopoulos AP. Omega–6/Omega–3 Essential Fatty Acid Ratio: The Scientific Evidence. World Review of Nutrition and Dietetics Vol. 92. 2003 https://www.karger.com/Article/PDF/73789