Polyunsaturated fatty acids (PUFAs) such as omega-3 and omega 6 fatty acids are considered essential fatty acids (EFAs) because they cannot be produced in the human body and are obtained through dietary sources (Saini & Keum, 2018). Whether or not EFA supplementation is necessary largely depends on an individual’s diet, genetics, health conditions, and pregnancy status. Though both omega-3s and omega-6s are important for metabolic function, have generally opposing effects. A large amount of omega-6 fatty acids in the diet is associated with inflammation, constriction of blood vessels, and platelet aggregation. These are necessary functions which aid in the acute inflammatory response and the process of bringing the necessary cells where they need to go and decreasing blood loss. They are important to protect people when they have a cut or injury (Saini & Keum, 2018). Excess inflammatory stimuli provide a microenvironment more prone to certain diseases, but ultimately disease and disease progression is multifactorial including but not limited to factors such as gender and genetic risk (Office of Dietary Supplements - Omega-3 Fatty Acids, n.d.). There are three main types of omega-3 fatty acids, alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA). Some studies propose that omega-3 fatty acid intake can help resolve inflammation and reduce the risk of cancer, cardiovascular disease (CVD), and other chronic and metabolic diseases, more specifically that EPA and DHA give have an anti-inflammatory effect (Saini & Keum, 2018). The North American diet has shown a low amount of omega-3 intake which increases the risk for chronic diseases in this general population (Saini & Keum, 2018). Reversing cardiac and neurologic disease with intake of omega-3 supplements is not a reliable and tested treatment but replacing saturated fats with an appropriate ratio of omega-3 and omega-6 fatty acids may help to optimize health (Santos et al., 2020).
There is a seemingly endless ocean of literature concerning the efficacy, uses, doses, sources, and types of EFAs, but to summarize the most consistent recommendations, the AHA recommends one to two servings of fatty fish per week to reduce the risk of congestive heart failure, coronary heart disease, ischemic stroke, and sudden cardiac death, especially when the seafood replaces less healthy foods (Office of Dietary Supplements - Omega-3 Fatty Acids, n.d.). There are three main types of omega-3 fatty acids, alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), and EPA In 2020, a particular omega-3 fatty acid, eicosapentaenoic acid (EPA), was approved by the FDA to reduce the risk of cardiovascular events in certain patients with or at high risk for CVD under the trade name Vascepa (Kelley-Hedgepeth, 2021). In June 2023, a recent research article was published in the Journal of the AHA which demonstrates that intake of omega-3 fatty acids more than 2grams a day has very strong association with reductions in triglyceride and non-high-density lipoprotein and cholesterol which supports the literature that omega-3s reduce the risk of certain CVD (Wang et al., 2023). The AHA still recommends that people should ideally get their nutrients from food but for those with dietary restrictions to eating oily, cold water fatty fish, supplementation may be a viable way to obtain EFAs (Office of Dietary Supplements - Omega-3 Fatty Acids, n.d.).
Omega-3s are found in marine derived and plant derived sources. Marine derived sources include fatty fish such as salmon, oysters, herring, mackerel and sardines and they contain EPA and DHA. Concerns for marine derived sources include the taste and smell of fish, heavy metal pollution, and dietary restrictions (Liu et al., 2022). ALA is a plant-based precursor of the other omega 3s and plant derived sources include flaxseeds, walnuts, chia seeds, and green leafy vegetables (Santos et al., 2020). A concern of using only plant derived sources is not getting enough DHA and EPA because the conversion of ALA to DHA and EPA is limited (Liu et al., 2022). Further research is needed for any uniform supplement source recommendations and individual assessment should always guide any treatment or supplement regimens. The AHA promotes seafood as part of a balanced diet for everyone, but only extends the recommendation for omega-3 supplementation for people with existing coronary heart disease (Office of Dietary Supplements - Omega-3 Fatty Acids, n.d.).
What's your source of omega3s this week?
References
Kelley-Hedgepeth, A. (2021, March 24). Omega-3 fatty acids and the heart: New evidence, more questions. Harvard Health. https://www.health.harvard.edu/blog/omega-3-fatty-acids-and-the-heart-new-evidence-more-questions-2021032422213
Liu, H., Wang, F., Liu, X., Xie, Y., Xia, H., Wang, S., & Sun, G. (2022). Effects of marine-derived and plant-derived omega-3 polyunsaturated fatty acids on erythrocyte fatty acid composition in type 2 diabetic patients. Lipids in Health and Disease, 21(1). https://doi.org/10.1186/s12944-022-01630-0
Office of Dietary Supplements - Omega-3 Fatty Acids. (n.d.). Ods.od.nih.gov. Retrieved July 10, 2024, from https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/#:~:text=Evidence%20of%20a%20protective%20effect%20for%20omega%2D3
Saini, R. K., & Keum, Y.-S. (2018). Omega-3 and omega-6 polyunsaturated fatty acids: Dietary sources, metabolism, and significance — A review. Life Sciences, 203, 255–267. https://doi.org/10.1016/j.lfs.2018.04.049
Santos, H. O., Price, J. C., & Bueno, A. A. (2020). Beyond Fish Oil Supplementation: The Effects of Alternative Plant Sources of Omega-3 Polyunsaturated Fatty Acids upon Lipid Indexes and Cardiometabolic Biomarkers—An Overview. Nutrients, 12(10), 3159. https://doi.org/10.3390/nu12103159
Wang, T., Zhang, X., Zhou, N., Shen, Y., Li, B., Chen, B. E., & Li, X. (2023). Association Between Omega‐3 Fatty Acid Intake and Dyslipidemia: A Continuous Dose–Response Meta‐Analysis of Randomized Controlled Trials. Journal of the AHA
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