Fish oil is a supplement that contains extracts from fatty fish like salmon, sardines, and mackerel. The main benefit behind fish oil comes from its omega-3 fatty acids, which are well known to have certain benefits for heart and skin health. But these fatty acids also play an important role in brain function and mental wellbeing.
Studies show that omega-3s can help ease symptoms of major depressive disorder and complement traditional treatments for mood disorders. In this article, we share what you need to know about fish oil omega-3s, including what they are, how they help with depression, and how you can get them in your diet. We also discuss whether you should take fish oil supplements and the potential side effects of doing so.
What are fish oil omega-3s?
Omega-3 fatty acids are a type of healthy fat that play an essential role in cognitive function, mental health, and overall wellbeing.
The most beneficial forms of omega-3s are called eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and they’re mainly found in fatty fish and fish oil. These two long-chain fatty acids are vital building blocks of cell membranes and have strong anti-inflammatory effects throughout the body. They also support heart health, brain development, and mood regulation.
Vegetarians may be wondering about plant-based options. There is another type of omega-3 called alpha-linolenic acid (ALA), which can be found in plant-based foods like walnuts, flexseeds, and chia seeds. However, the body isn’t very efficient at converting ALA into EPA and DHA – in fact, less than 10% of ALA is typically converted into the active forms that can actually be used by the brain and body.
Most people don’t consume enough fish to meet the recommended intake of EPA and DHA, and that’s where fish oil supplements come in. These supplements can make it easier to up your intake of omega-3s, especially if you’re looking to support your brain and mental health.
How has our intake of omega-3 changed over time?
Over the past 150 years, our world has experienced significant changes in diet, especially in Western countries. As a result, most of us have greatly reduced our intake of omega-3 fatty acids. Industrialization and population growth have meant that traditional sources of omega-3, like fish, wild game, and certain plants, have become less common in the average everyday diet.
At the same time, there’s been a sharp increase in the consumption of saturated fats and omega-6 fatty acids, mostly thanks to the use of processed vegetable oils like corn, soybean, and safflower oil in packaged and fast foods.
It’s thought that once upon a time, humans consumed both omega-3s and omega-6s in roughly equal amounts. Today, however, people in developed countries are estimated to consume up to 15 times more omega-6 than omega-3. This imbalance matters, because omega-6 and omega-3 fats compete for the same enzymes in the body. When we consume too much omega-6, it could lead to inflammation if not balanced with enough omega-3 intake.
It’s important to note that omega-3 intake varies widely around the world. For example, people in Japan consume five times more omega-3 than those in many Western countries, and studies suggest this contributes to lower rates of cardiovascular disease and depression in Japan.
How do omega-3s affect the brain?
The omega-3 fatty acids EPA and DHA play a critical role in brain function and development at every stage of life.
During pregnancy, DHA supports the development of the baby’s brain and nervous system. Research shows that pregnant women who consume more fish or take fish oil supplements tend to have children who score higher on tests of brain function and intelligence in early childhood.
These two fatty acids continue to be important for maintaining healthy brain function throughout life. DHA and EPA are highly concentrated in the brain’s cell membranes, where they help preserve cell structure and support communication between brain cells. For older adults, lower levels of DHA in the blood have been associated with smaller brain volume, which is a sign of accelerated brain aging.
It’s not just humans who benefit from omega-3s, either. Animal studies have shown that diets lacking in omega-3s result in lower DHA levels in the brain, which is often linked to problems with learning and memory.
Read More: Do Antidepressants Work and How Effective Are They?
How fish oil can help with depression
Research shows that omega-3 fatty acids can help manage symptoms of depression. There have been a number of clinical studies and meta-analyses that found fish supplements, especially those high in EPA, can help reduce depressive symptoms. In some cases, the effects are comparable to those of standard antidepressant medications.
That’s not to mean you should take fish oil instead of medication. In fact, the most significant benefits appear when fish oil is used as an add-on treatment. People who are already taking antidepressants often experience greater symptom relief when fish oil supplements are added to their regimen, especially when the supplements contain higher ratios of EPA to DHA.
Researchers are still working to understand exactly how omega-3s support mood, but a few theories include:
- Omega-3s may have an effect on serotonin and its receptors in the brain
- Depression has been linked to chronic inflammation, and omega-3s are known to have anti-inflammatory properties
- Omega-3s can easily pass through brain cell membranes, potentially interacting with mood-related molecules.
Based on clinical trials, the most effective omega-3 supplements for depression seem to contain at least 60% EPA, and doses range from 1 gram to 6 grams per day.
See: Postpartum Depression: Causes, Symptoms & Treatment
Omega-3s for other mental health conditions
Most research around omega-3 has focused on depression, but scientists are also exploring its role in other psychiatric disorders. So far, results are mixed – some findings are promising, but more research is needed.
That said, some conditions that omega-3s may potentially benefit include bipolar disorder, obsessive-compulsive disorder (OCD), postpartum depression, attention-deficit hyperactivity disorder (ADHD), borderline personality disorder, psychotic disorders, and schizophrenia or schizoaffective disorders.
Keep Reading: TMS Treatment for Borderline Personality Disorder
Will fish oil improve my brain if I’m healthy?
Research has shown that omega-3s can help improve symptoms of depression, but can it enhance your mood or improve brain function if you’re healthy?
There have been some observational studies that found people who eat more omega-3-rich fish tend to have better brain health over time, but these studies only show a correlation, they don’t prove that dish oil supplements directly improve brain function.
When it comes to healthy individuals with no existing cognitive concerns, most high-quality clinical trials suggest that fish oil supplements don’t significantly enhance brain performance. For example, one study involving 159 healthy young adults found no improvement in brain function after taking 1 gram of fish oil per day compared to a placebo. Similar research in older adults without cognitive impairment also showed that fish oil didn’t significantly improve memory, attention, or the speed of mental processing.
That said, omega-3s can still play an important role in maintaining brain health over the long term, especially when it comes to supporting mood, reducing inflammation, and healthy brain aging.
Dietary sources of omega-3
We mentioned earlier that most of us don’t get enough omega-3s in our daily diet. So where can you find these healthy fatty acids? Some dietary sources of omega-3 include:
Fatty fish
Fatty, cold-water fish are the richest natural source of the long-chain omega-3s EPA and DHA, which are the most beneficial for brain and mental health. These include salmon, sardines, mackerel, herring, anchovies, and trout.
Omega-3 supplements
Fish oil supplements contain concentrated amounts of EPA and DHA, and they can be a good option for those who don’t like seafood or don’t eat fish regularly. Most over-the-counter capsules provide 0.3 to 0.6 grams of omega-3 per capsule, usually at a 3:2 EPA to DHA ratio.
Fortified foods
Some everyday foods are now enriched with omega-3s, making it easy to boost your daily intake. These might include eggs, milk, bread, yogurt, or breakfast cereals. You can find out how much omega-3 is included in these foods by checking the nutrition panel on their packaging.
Plant-based sources (ALA)
Vegetarian and vegan sources of omega-3 provide ALA, a precursor to EPA and DHA. The body can convert ALA into the more active forms, but the process is not very efficient, especially if you are stressed, aging, unwell, or have dietary deficiencies.
Some plant-based sources of ALA include flaxseeds and flax oil, chia seeds, walnuts, hemp seeds and hemp oil, canola oil, and soybean oil. You might also want to consider algae-based supplements, which provide a direct source of DHA and are suitable for vegans and vegetarians.
See: How Diet and Exercise Affect Your Mental Health
Should you take fish oil supplements?
You may want to consider taking fish oil supplements if you’re experiencing depression or mild cognitive impairment. Based on available research, these groups appear to benefit the most when it comes to omega-3s supporting the brain and mental health.
So, how much fish oil should you take? There aren’t any official guidelines for how much omega-3 you need to improve your mental health, but studies have typically used daily doses between 1,000 and 2,000 mg of combined EPA and DHA. Some people might need more, especially if you’re taking supplements alongside antidepressant medication.
That said, it’s important to read labels carefully. A 1,000 mg capsule of fish oil doesn’t necessarily contain 1,000 mg of omega-3s. It might only have 300-600 mg, depending on the product. If you’re taking fish oil to manage major depression, look for supplements with a higher concentration of EPA, which is the omega-3 most consistently linked to mood improvements.
Now, you might be wondering if fish oil is safe, and the answer is yes if taken at appropriate doses. In the U.S., the Food and Drug Administration (FDA) has set an upper intake limit of up to 3,000 mg of omega-3 per day, while the European Food Safety Authority (EFSA) has set up to 5,000 mg per day.
If you’re taking blood-thinning medications or have a surgery scheduled, be sure to speak with your doctor before starting a supplement. Fish oil may have mild blood-thinning effects and might not be suitable in all cases.
Keep Reading: How do Medications and Psychotherapy Work Together? The Life-Changing Benefits of Combining Medication and Therapy
What are the side effects of omega-3 supplements?
Omega-3 supplements are generally considered safe and well tolerated when taken at the recommended doses. But like any supplement, they may cause side effects in some people.
Most side effects are mild and tend to occur more frequently when doses exceed 3,000-5,000 mg per day. These might include:
- Nausea
- Diarrhea
- Heartburn or indigestion
- Abdominal discomfort
- Fishy aftertaste or ‘fish burps’.
If you’ve tried fish oil supplements in the past and couldn’t stand the taste or smell, you’ll be happy to note that these side effects are now less common than they used to be, thanks to improved purification and manufacturing techniques.
There are also some concerns about omega-3s increasing the risk of bleeding. These have mostly been disproven, but caution is still advised if you:
- Take blood-thinning medications
- Have a bleeding disorder
- Are preparing for surgery.
If any of these apply to you, be sure you speak with a healthcare provider before taking fish oil.
Some other considerations to note:
- Pregnancy: Long-term data on fish oil supplementation during pregnancy is still limited. If you’re pregnant, use omega-3 supplements cautiously and under medical guidance.
- Seafood allergies: It’s not yet clear whether fish oil supplements are safe for people with seafood allergies. If you have an allergy, consult with your doctor before taking omega-3 supplements.
Get support for depression
Omega-3 fatty acids play an important role in supporting our mood and keeping our brains healthy, but they’re not a substitute for treating depression with a mental health professional. In fact, the research shows that they’re most effective when used alongside antidepressant medications.
If you’re experiencing symptoms of depression or another mood disorder, our team at BestMind Behavioral Health is here to help. We offer compassionate, evidence-based care for a wide range of mental health conditions including depression, anxiety disorders, bipolar disorder, ADHD, and post-traumatic stress disorder (PTSD).
Whether you’re looking for medication to relieve symptoms or exploring alternative therapies like transcranial magnetic stimulation (TMS), our team can customize a treatment plan that works best for your needs. Contact us today to schedule a consultation or explore your options.
