There is evidence that omega-3 fatty acids can migrate across the cell membranes of brain cells and interact with molecules known to play a role in mood regulation, according to Harvard Health Publishing. Specifically, one theory suggests that the anti-inflammatory properties of the omega-3 fatty acids found in fish oil help stabilize mood.
There is some evidence that depression involves inflammation in different parts of the nervous system, according to the study published in Frontiers in Immunology in 2019. “And omega-3 fatty acids reduce a variety of inflammatory products, including tumor necrosis factor and interleukin-2, -6, and -1 beta,” says Dr. Muskin. This anti-inflammatory process may be mood-regulating.
That said, people can get depressed without having excessive inflammatory activity, says Dr. David Mischoulon, psychiatrist and director of the clinical and research program for depression at Massachusetts General Hospital in Boston. “Inflammation isn’t the only road to depression, but we believe it contributes to it.”
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What Does Science Say About Fish Oil For Depression?
Overall, more research is needed, but the studies that have been conducted so far are encouraging.
According to Dr. Mischoulon, extensive work has been done on fish oil both as an add-on treatment and as a standalone treatment for depression. “By and large, studies show that omega-3 fatty acid intake is effective and safe,” he says.
The problem is that the way studies are designed varies greatly in terms of dosage, the scope of the study, and the source and formulation of the fish oil itself. Hence, the conclusions of the research should be interpreted with some caution. Mischoulon explains. “There’s no clear idea of the optimal preparation or dose,” he says.
Additionally, some studies that showed no benefit may have drawn from a population of people with depression who did not initially have high rates of inflammation – and therefore failed to benefit from the anti-inflammatory effects of fish oil. (The opposite could also be true.)
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According to a systematic review and meta-analysis of 10 prospective studies published in the journal Asia-Pacific Psychiatry in December 2018, people who eat more fish have an 11 percent lower risk of developing depression than people who eat less fish eat . A separate review and meta-analysis published in the Journal of Affective Disorders in November 2016 suggests that consuming 0.6 grams of EPA and DHA from fish is associated with a lower risk of the mood disorder (3 ounces of salmon contains approximately 1 , 5 to 1.75 grams of EPA and DHA according to the National Institutes of Health).
And when it comes to supplements, in a review published in the Journal of Integrative Neuroscience in December 2017, researchers concluded that the supplement was effective in treating symptoms of depression based on clinical studies comparing a placebo with a fish oil supplement, but best used as an add-on to traditional prescription antidepressants rather than by itself. According to the studies examined, there were no serious side effects associated with taking the supplements.
A meta-analysis recently published in BMC Psychiatry in May 2020 looked at 10 randomized, controlled trials of 910 people with depression who were taking either omega-3 supplements or a placebo. It concluded that both high- and low-dose EPA and DHA supplements were more effective at relieving symptoms compared to a placebo, and this effect was greatest in the early stages of depression.
Despite this promising evidence, it’s still important to note that research has not yet defined the specific role fish oil should play in mental health care, says Dr. Ken Duckworth, Chief Medical Officer, National Alliance on Mental Illness.
Non-drug lifestyle behaviors such as self-care, eating healthy, exercise, and socializing are much more indicative of helping with mood. “I wouldn’t start with fish oil,” says Dr. Duckworth. “Fish oil is not a panacea for mood disorders.”
Is Fish Oil an Antidepressant?
According to current data, it is not yet clear whether fish oil can work as an antidepressant, says Muskin.
Antidepressants work on chemicals in the brain that are thought to affect mood, such as serotonin, norepinephrine, and dopamine. Fluoxetine (Prozac) is a widely used selective serotonin reuptake inhibitor drug used to treat depression. Although it is not yet clear how antidepressants work, this drug can increase the amount of serotonin in the synapses between brain cells (how brain cells communicate). Serotonin has many effects throughout the body, but in the brain it is thought to play a role in mood, appetite, and sleep, among other things.
While there is research to suggest that fish oil can improve symptoms of depression, studies have not yet shown how it affects, or if it does, the neurotransmitters in the brain. So it’s impossible to know if fish oil works similarly to antidepressants, says Muskin.
Do doctors recommend fish oil – or other omega-3 fatty acids – for depression?
The short answer isn’t regular, at least not yet. The long answer is a little more complicated. Depending on your own risk for depression and other health problems, your doctor may recommend fish oil supplements.
Muskin and Mischoulon state that they recommend fish oil supplements to some patients based on their diet and general health needs. But this recommendation does not apply to everyone either.
Eating fish is generally recommended as part of a healthy diet. (The latest U.S. Department of Agriculture dietary guidelines recommend U.S. adults eat 8 ounces of fish per week.)
If you and your doctor determine that trying a fish oil supplement is a good idea, you know that there is no conclusive evidence of an optimal dose. Based on your diet and personal history, your doctor can help you determine the best dose for you.
What Kind of Omega-3 Fatty Acids or Fish Oil is Best for Depression?
When choosing a particular fish oil supplement for depression, it is important for you and your doctor to consider how much EPA and DHA it contains.
A meta-analysis published in Psychotherapy and Psychosomatics in September 2019, co-authored by Mischoulon, suggests that supplements with an EPA to DHA ratio of 2 to 1 or greater and 1 to 2 grams of EPA are effective based on previous data. Other research suggests that EPA is a more effective anti-inflammatory agent for depression, according to data published in Molecular Psychiatry in January 2016.
However, the amount of DHA and EPA a fish oil supplement contains is not always easy for consumers to find out. Some reputable, high-quality brands will present this information on the label or on their website; others will only list total omega-3s.
And remember: dietary supplements are not tested by the Food and Drug Administration before they are marketed to consumers. Hence, it is important to research the brand. Muskin recommends finding fish oil supplements made from fish oil from small fish such as anchovies and sardines. free from impurities such as mercury; and transparent about fillers and ingredients that are used to make the casing, such as gelatin, soy or lactose, in case you have an allergy or intolerance.
How much you need to take is best left to your doctor. Muskin notes that more is not necessarily better when it comes to consuming fish oil for mental health, and it can quickly become unnecessarily expensive.
It is clear that if you are concerned that you are suffering from depression, you should not try to treat it yourself with therapy, including fish oil. Talk to your GP to get started. They can screen you for depression and then determine the appropriate treatment for you.
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