Plant-Based Nutrition: Episode # 2 – Omega-3 Fatty Acids

In our first episode of this Plant-Based Nutrition series we tackled the pseudoscience surrounding plant-based protein. For this episode we will dive into all-things omega-3’s!

Omega-3 fatty acids are indisputably an important part of a healthy diet. But can you get enough omega-3 fatty acids from just plant-based sources?

This week, let’s explore the role of omega-3’s in plant-based diets and the related health outcomes! 

What are Omega-3 Fatty Acids?

Omega-3 fatty acids are healthy essential fatty acids that are obtained from our diet. The 3 main types of omega-3 fatty acids are alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA). Our bodies cannot make ALA, which means that you must get it from the foods you consume [1]. ALA is a plant-derived fatty acid, whereas EPA and DHA are mostly found in fish [1,2].

Omega-3’s are not to be confused with their cousin fatty acid, omega-6’s, which differ in their chemical structure and function in the body. In contrast to omega-3’s, omega-6 fatty acids are believed to be pro-inflammatory and are recommended in lower amounts [2].

Why should you care about omega-3’s?

There are many health benefits to consuming omega-3’s.
Omega-3 fatty acids make up an integral structural component of our cell membranes in all tissues of the body [3]. DHA is also considered very important for brain function and eye health [4,5] with some evidence suggesting that omega-3’s, particularly DHA and EPA, may play a role in lowering our risk of developing certain mental health conditions, including depression, dementia and bipolar disorder [4].

Furthermore, omega-3 fatty acids have anti-inflammatory effects, which are essential for regulating the immune response of our body. And they may even protect us from inflammation-related illnesses [6]!

Arguably the most investigated health benefit of omega-3’s is their protective role against heart disease. Specifically, there is a significant body of research that has previously reported that supplementing with EPA and DHA may help reduce the risk of heart disease and its associated health outcomes [7]. But lately there has been  some controversy surrounding the protective effect of omega-3 supplementation in heart disease, since some newer studies were unable to confirm this beneficial effect [8,9]. 

Also, the role of ALA and heart health is not widely established. Only a few studies that have investigated ALA consumption have suggested a modest lowering of heart disease risk [10].

Nonetheless, the overall evidence suggests that omega-3’s may provide some cardioprotective benefit – or at the very least, no ill effects.

Dietary Sources of Omega-3’s

EPA and DHA are found in fatty fish, algae and other seafood, as well as fish oils and krill oils.

On the other hand, dietary sources of ALA include [11]:

• Flaxseed oil – 3 grams of ALA per 1 tablespoon
• Chia seeds – 5 grams of ALA per 1 ounce
• Hemp seeds –6 grams of ALA per 3 tablespoons
• Walnuts – 3 grams of ALA per 1 cup

Dietary Recommendations

The daily recommendation for ALA is 1.6 grams for healthy males and 1.1 grams for healthy females [1].

There is not enough data available to firmly establish ideal amounts for how much EPA and DHA should be consumed every day [1]. There are also no set guidelines for individual intakes of EPA or DHA alone.

Some sources recommend an adequate intake (AI) for omega-3’s, which is the estimated nutrient intake that is assumed to be adequate in healthy people. The AI for EPA plus DHA is 0.25-0.50 grams per day [12]. 

Given the documented health benefits of omega-3’s, the American Heart Association recommends eating at least 2 servings of fatty fish per week for healthy adults [13]. But these recommended values vary depending on different health conditions [1].

This may sound worrying if you follow a plant-based diet! But, don’t worry, read below for tips to overcome this and reap all the benefits of plant-based omega-3’s!

Considerations

There are a few things to keep in mind when consuming only plant-based sources of omega-3’s.

Most people already get enough ALA in their diets from foods they eat. Also, ALA can be converted into EPA and DHA in the body, but only in extremely small amounts, so doubling up on ALA may not be the best solution [1].

Including EPA and DHA in your diet from foods or supplements is the most practical way to increase your intake of these omega-3’s.

But the good news is that this can be achieved by taking vegan supplements of omega-3’s. In particular DHA and EPA supplements made from seaweed or algae, such as algal oil, are available to help boost your intake of these omega-3’s.
Some of these supplements are in the form of DHA only. And since your body can retro-convert DHA into EPA, supplementing with DHA alone may be effective for increasing EPA levels as well. [2].

Another important thing to consider is making sure you are getting the right balance of omega-3s to omega-6’s. The conversion from ALA to DHA and EPA is even tougher in those who consume a diet high in omega-6 fatty acids (which is the case for most people, and even more so for vegans)! Compared to omnivores, plant-based diets tend to be higher in omega-6’s [14,15].

But a diet with a higher ratio of omega-6’s to omega-3’s can increase inflammation and the risk of developing inflammatory diseases [16]. So, to help improve your omega-3 status make sure to reduce intakes of unhealthy foods containing high amounts of omega-6 fatty acids, particularly highly processed foods and foods cooked in corn oil, safflower oil and other vegetable oils.

Take-Away Tips

You can get enough omega-3’s on a plant-based diet.

To get all the health benefits associated with omega-3’s, include vegan supplements of EPA and DHA along with plant-based food sources of ALA. This will help ensure you are getting enough of these healthy fats in your diet.

Also, it is important to lower the ratio of omega-6 to omega-3’s by reducing your intake of foods high in omega-6 fatty acids, which may help improve your overall omega-3 status.
 
Are you wondering about other nutrients to optimize on a plant-based diet? Stay tuned for our next episode on Vitamins!

References

1. National Institutes of Health (2019). Omega-3 Fatty Acids. Office of Dietary Supplements.

2. Oregon State University (2019). Essential Fatty Acids. Micronutrient Information Center.

3. Surette M. E. (2008). The science behind dietary omega-3 fatty acids. Canadian Medical Association Journal, 178(2), 177–180.

4. Lange K.W. (2020). Omega-3 fatty acids and mental health. Global Health Journal, 4(1), 18-30.

5. Querques, G., Forte, R., & Souied, E. H. (2011). Retina and omega-3. Journal of Nutrition and Metabolism, 2011, 748361.

6. Calder P. C. (2010). Omega-3 fatty acids and inflammatory processes. Nutrients, 2(3), 355–374.

7. Chaddha A., & Eagle K.A. (2015). Omega-3 Fatty Acids and Heart Health. Circulation, 132:e350–e352.

8. Bowman, L., Mafham, M., Wallendszus, K., Stevens, W., Buck, G., Barton, J., … Armitage, J. (2018). Effects of n-3 fatty acid supplements in diabetes mellitus. New England Journal of Medicine, 379(16), 1540–1550.

9. Manson, J. A. E., Cook, N. R., Lee, I. M., Christen, W., Bassuk, S. S., Mora, S., … Buring, J. E. (2019). Marine n-3 fatty acids and prevention of cardiovascular disease and cancer. New England Journal of Medicine, 380(1), 23–32.

10. Fleming, J. A., & Kris-Etherton, P. M. (2014). The evidence for α-linolenic acid and cardiovascular disease benefits: Comparisons with eicosapentaenoic acid and docosahexaenoic acid. Advances in Nutrition, 5(6), 863S–76S. https://doi.org/10.3945/an.114.005850

11. USDA National Nutrient Database for Standard Reference. (2016). Nutrients: 18:3 n-3 c,c,c (ALA) (g). The National Agricultural Library.

12. World Health Organization. (2008). Interim Summary of Conclusions and Dietary Recommendations on Total Fat & Fatty Acids. Joint FAO/WHO Expert Consultation on Fats and Fatty Acids in Human Nutrition, 10-14, WHO, Geneva

13. American Heart Association. (2017). Fish and Omega-3 Fatty Acids.

14. Gerster H. (1998). Can adults adequately convert alpha-linolenic acid (18:3n-3) to eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3)?. International Journal for Vitamin and Nutrition Research, 68(3), 159–173.

15. Burns-Whitmore, B., Froyen, E., Heskey, C., Parker, T., & San Pablo, G. (2019). Alpha-Linolenic and Linoleic Fatty Acids in the Vegan Diet: Do They Require Dietary Reference Intake/Adequate Intake Special Consideration?. Nutrients, 11(10), 2365.

16. Russo G. L. (2009). Dietary n-6 and n-3 polyunsaturated fatty acids: from biochemistry to clinical implications in cardiovascular prevention. Biochemical Pharmacology, 77(6), 937–946.