What is depression?

Depression is a leading cause of disability that globally affects approximately 264 million people.1 While this common mental disorder is characterized by short-lived emotional responses to everyday challenges and mood fluctuations, it can become a serious health condition when it is long-lasting with moderate to severe intensity for greater than 2 weeks.1 Symptoms of depression can often interfere with everyday life like going to work or school, and at its worst, it can sometimes lead to suicide.

Medication is NOT always the answer!

There are many effective ways to treat moderate and severe depression. Health-care providers often use antidepressant medications as the front line of treating depression. These drugs, including Selective Serotonin Reuptake Inhibitors (SSRIs), Serotonin–norepinephrine reuptake inhibitor (SNRIs), tricyclic antidepressants (TCAs) are designed to increase serotonin transmission.2 Serotonin is a neurotransmitter that plays a main role in how happy we feel. However, they are only effective for moderate-severe depression and not recommended for treating mild depression.1 Other therapies, such as psychotherapy, cognitive behavioral therapy, and learning stress management techniques, are recommended in concurrent with medication.2 Despite advancements in these optimized treatments, less than 50% of patients achieve full remission.3 As a result, researchers have been committed to finding new avenues of treatment. With more alternative and integrative approaches, researchers have found that exercise, nutrition, and sunlight can reduce depressive symptoms as well as using the environment to connect mind and body. One way that researchers have been exploring is the role of omega-3 polyunsaturated fatty acids in the treatment of chronic diseases, including mood disorders. 

What is omega-3?

Omega-3 polyunsaturated fatty acids are important components to neuronal cell membranes in the human body as well as providing calories for body energy and for other bodily functions to run properly.4 The consumption of omega-3 has anti-inflammatory effects and plays an essential role in the brain. Some depressive symptoms can be related to chronic stress, which alters activation of the peripheral immune system and can account for chronic inflammation.5. Decreasing  neuroinflammation is important to depression and other mood disorders. 

The key role of omega-3s is releasing eicosanoids, active lipid mediators that regulate immune function and reduce inflammation as well as preserving brain structural functions.5 

Is omega-3 really effective in treating depression?

In a randomized clinical trial study, researchers tested for the effectiveness of omega-3 supplements in improving depressive symptomatology amongst clinically diagnosed patients as well as healthy participants. The study found that the use of omega-3 fatty acids as a therapeutic agent was effective in both subjects.6 Similarly, in another randomized controlled trial, Parletta et al. found a positive correlation between a Mediterranean-style diet supplemented with fish oil and improvement in mental health amongst adults struggling with depression. In six months, 152 adults’ mental health was accessed with lifestyle change in diet.7 The researchers found that within three months, the intake of a Mediterranean diet was significantly associated with better coping mechanisms and lower depression and anxiety. This statistic supports the conclusion that healthy dietary changes can result in an improvement in mental health, especially depression.7 

How do we get our omega-3?

These fatty acids can be naturally found in many plant-based food sources, some fortified foods, and dietary supplements. Some examples include nuts and seeds (chia seeds, walnuts, and flaxseed), soy milk, edamame, seaweed, algae, and plant oils.4 Because omega-3 is abundant in fish and other seafood, many epidemiological studies suggest that societies with high consumptions of these foods have a lower prevalence of depression.3 However, the most recommended source of omega-3 is through plant-based foods.

Why Plant-based Nutrition?

Whole foods describes natural foods that are not heavily processed. Although whole food plant-based eating cuts down on certain foods like dairy and meat, these diets still offer all the necessary carbohydrates, fats, fibers, vitamins and minerals for optimal health. In this way, plant-based diets have reduced risks of developing high blood pressure, heart disease, depression, and diabetes as well as improving overall well-being. 

Final Thoughts

Overall, the use of omega-3 polyunsaturated fatty acids supplementary treatment reduces symptoms of depression. However, there is more research that needs to be done to gain a better understanding of how they work and long-term effects. It is recommended that you talk to your doctor before replacing traditional treatments with increased intake of omega-3 supplements. 


  1. Depression fact sheet. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/depression. Published January 30, 2020. Accessed February 5, 2021.
  2. Deacon G, Kettle C, Hayes D, Dennis C, Tucci J. Omega 3 polyunsaturated fatty acids and the treatment of depression. Critical Reviews in Food Science and Nutrition. 2016 Oct 17; 57(1): 212-223. DOI: 10.1080/10408398.2013.876959
  3. Su KP. Biological mechanism of antidepressant effect of omega-3 fatty acids: how does fish oil act as a ‘mind-body interface’? Neurosignals 2009; 17: 144-152. DOI: 10.1159/000198167
  4. Omega-3 fatty acids: fact sheet for consumers. National Institutes of Health. https://ods.od.nih.gov/factsheets/Omega3FattyAcids-Consumer/. Updated October 1, 2020. Accessed February 6, 2021.
  5. Grosso G, Galvano F, Marventano S, et al. Omega-3 fatty acids and depression: scientific evidence and biological mechanisms. Oxid Med Cell Longev. 2014;2014:313570. doi:10.1155/2014/313570
  6. Grosso G, Pajak A, Marventano S, et al. Role of omega-3 fatty acids in the treatment of depressive disorders: a comprehensive meta-analysis of randomized clinical trials. PLoS One. 2014;9(5):e96905. Published 2014 May 7. doi:10.1371/journal.pone.0096905
  7. Parletta N, Zarnowiecki D, Cho J, et al. A Mediterranean-style dietary intervention supplemented with fish oil improves diet quality and mental health in people with depression: A randomized controlled trial (HELFIMED). Nutr Neurosci. 2019;22(7):474-487. doi:10.1080/1028415X.2017.1411320


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