By: Israel Aguilar, CSUN Dietetic Intern Cohort 2019-2020

Polyunsaturated fatty acids (PUFAs) may sound more complex than they actually are. There are two categories of PUFAs that are known: omega-3 fatty acids and omega-6 fatty acids. These fatty acids are important to have in our meals, especially omega-3 fatty acids, because they are known to help prevent cardiovascular disease and inflammation around the body. In today’s blog, we will discuss in further detail the types of omega-3 fatty acids and the food sources that contain them. 

As mentioned before, there are various types of PUFAs, each with their own unique chemical structures. To start, there are three types of omega-3 fatty acids that are found commonly in foods. These three types are alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA). These omega-3 fatty acids each have different carbon tails in their structure but have the same role of protecting the heart from arterial plaque build-up by lowering triglycerides levels in the blood.¹ Omega-3 fatty acids also have the capability of lowering inflammation around the body by inhibiting the production of interleukin-2.² In addition, omega-3 fatty acids bind to certain nuclear receptors in the body (e.g., HNF-4a) in order to inhibit the gene expression for inflammation.² Another important characteristic of omega-3 fatty acids is how they regulate blood pressure by improving arterial response.² This is accomplished when DHA and EPA self-insert into the phospholipid membrane of cells and enhance systematic arterial compliance.² To obtain these benefits from omega-3 fatty acids, it’s important to know what quantity one should consume and what sources to eat. 

There are various foods that contain omega-3 fatty acids. Common food sources that contain omega-3 fatty acids are salmon, mackerel, snapper, tuna, and scallops.³ While these food sources are mainly marine-based, alpha-linolenic acid, a precursor to EPA and DHA, can be found in plant sources such as flax seeds and chia seeds.³ Based on the USDA database, chia seeds have about 17 grams of alpha-linolenic acid per 100 grams and salmon has 4.5 grams of omega-3 fatty acids per 100 grams.^{4, 5} As for recommended amounts of omega-3 food sources, the American Heart Association recommends that the public consume 125 grams of oily fish and 125 grams of lean fish at least twice a week.⁶ Lastly, the recommended amount of alpha-linolenic acid for an individual to consume is 1.6 grams per day along with the consumption of foods high in omega-3 fatty acids. These are general guidelines provided by various organizations to guide individuals in meeting their daily requirements for omega-3 fatty acids and obtain the health benefits from this fat. 

Overall, incorporating omega-3 fatty acids into one’s diet is beneficial and prevents the development of heart problems. Currently, the Western diet contains a large amount of omega-6 fatty acids and minimal amounts of omega-3 fatty acids with a ratio of 20:1.⁷ While omega-6 fatty acids do have their own benefits, they promote a prothrombotic state and inflammation in the body when consumed in large amounts, which may increase the development of health disparities (e.g., atherosclerosis).⁷ Thus, following the guideline of consuming fish at least two times a week will help meet the dietary recommendation for omega-3 fatty acids and balance the ratio between omega-6 and omega-3 fatty acids. 

Recipe: Banana Almond Flax Smoothie⁸ 

Ingredients: 

• 1 medium banana 
• 2/3 cup of unsweetened almond milk 
• 1/3 cup fat free plain Greek yogurt 
• 1 ½ tbsp of almond butter  
• 1 tbsp ground flaxseed meal 
• 1 tsp honey 
• 3-4 drops of almond extract 

Directions: 

• Blend all ingredients together until well mixed.  

References 

1. Skulas-Ray, AC, Kris-Etherton, PM, Harris, WS, Heuvel, JPV, Wagner, PR, West, SG. Dose-response effects of omega-3 fatty acids on triglycerides, inflammation, and endothelial function in healthy persons with moderate hypertriglyceridemia. (author abstract) (report). The American Journal of Clinical Nutrition. 2011;93(2):243-252. doi:10.3945/ajcn.110.003871 
2. Mohebi-Nejad, A, Bikdeli, B. Omega-3 Fatty Acids and cardiovascular disease. National Research Institute of Tuberculosis and Lung Disease. 2014;13(1):6-14. 
3. Fereidoon, S, Priyatharini A. Omega-3 polyunsaturated fatty acids and their health benefits. Annual Review of Food Science and Technology. 2018;9(1):345-381. doi:10.1146/annurev-food-111317-095850 
4. Seeds, Chia Seeds, Dried. U.S. Department of Agriculture. https://fdc.nal.usda.gov/fdc-app.html#/food-details/170554/nutrients. Published April 1, 2019. Accessed April 24, 2020. 
5. Fish, Salmon, Atlantic, Farmed, Cooked, Dry, Heat. U.S. Department of Agriculture. https://fdc.nal.usda.gov/fdc-app.html#/food-details/175168/nutrients. Published April 1, 2019. Accessed April 24, 2020. 
6. Tur, JA, Bibiloni, MM, Sureda, A, Pons, A. Dietary sources of omega 3 fatty acids: Public health risks and benefits. British Journal of Nutrition. 2012;107(2):S23-S52. 
7. Artemis, PS. An increase in the omega-6/omega-3 fatty acid ratio increases the risk for obesity. Nutrients. 2016;8(3):128. doi:10.3390/nu8030128 
8. Jacklyn. Banana Almond Flax Smoothie. Cooking Classy^TM. January 10, 2016. Accessed April 24, 2020. https://www.cookingclassy.com/banana-almond-flax-smoothie/