Fish Oil for Depression

February 16, 2009 Written by JP    [Font too small?]

There are many people out there who suffer from varying degrees of depression. The causes are sometimes specific, such as a reaction to a traumatic event or a dysfunction of the thyroid gland. But most of the time, the origin of low mood states is simply unknown. When that’s the case, the typical treatment prescribed by a conventional doctor is an antidepressant medication. For some, such medications are literally life-savers. On the other hand, some people simply don’t react well to them. There’s also a sizable group of individuals who aren’t even open to the suggestion of taking this form of “therapy”.

Today I want to share some recent findings about a natural alternative that may help support a healthy mood – fish oil. But not all fish oil is created alike. Knowing some specifics about this product is helpful and will increase the odds of deriving the desired benefits it may provide.

The Health Benefits of Fish Oil

Cardiovascular Health Research shows that consumption of EPA and DHA Omega-3 fatty acids may reduce the risk of coronary heart disease. As such, the American Heart Association (AHA) recommends the daily dietary intake of Omega-3 essential fatty acids EPA and DHA at 1,000 mg per day for cardiovascular health.
Brain/Neurologic Health The support of cognitive function and neurologic health by the Omega-3 fatty acids EPA and DHA is supported in multiple research studies.* In addition, Omega-3 fatty acids have been shown to support a healthy mood and emotional state.*
Joint/Immune Health Omega-3 fatty acids, especially EPA, support joint health in the body.* Due to their impact on lipid membranes, they also promote normal and healthy balance in the body’s immune pathways and responses.*
Vision Health The Omega-3s EPA and DHA have been found to help support the health of the macula and retina of the eye.* In addition, support of healthy and normal lubrication of ocular structures has been indicated.*
Weight Management When used in combination with healthy diet and exercise program, research has shown Omega-3 fatty acids to enhance the body’s ability to address its fat metabolism and promote a healthy weight.*

The first thing to know about fish oil is that it contains two primary omega-3 fatty acids. The first is called EPA (eicosapentaenoic acid). The second is known as DHA (docosahexaenoic acid). The most vital detail to look for when you buy fish oil is the content of EPA and DHA. Another important consideration is the purity of the fish oil. Here’s a brief overview of what I mean:

A fish oil soft gel often contains a total of 1,000 mg of fish oil. But what’s really important is how much of that 1,000 mg is comprised of EPA and DHA. Why? Because those two fatty acids are thought to be the “active” ingredients – the substances that provide the health effects.

Example 1: Product A may contain 1,000 mg of fish oil consisting of 250 mg of EPA and 125 mg of DHA.

Example 2: Product B also contains 1,000 mg of fish oil. But this product is concentrated to 500 mg of EPA and 250 mg of DHA.

It’s obvious in the above example that the second product is significantly more powerful. The size of the soft gel may be the same, but the impact will differ. In all likelihood, the price tag will differ too. The more potent products are often more expensive. But remember that you also need to take less. In the example provided, you’d need to take two soft gels of the first product in order to get an equal amount of EPA and DHA in the second product.

The second major issue with fish is purity. Perhaps you’ve heard or read in the news about concerns regarding heavy metal and pesticide contamination in our fish supply. This is a reasonable concern for an increasingly polluted world. Similar red flags have also been raised about fish oil. To address these concerns, many reputable supplement manufacturers are now testing for the potential dangers in their products. Some of these same manufacturers take it one step further and purify their fish oil by a process called “molecular distillation”. This process guarantees that the fish oil will be free of mercury and other unwanted toxins.

Ladies First

One group that suffers disproportionately with depression is menopausal women. A study published in the February issue of the American Journal of Clinical Nutrition may offer hope in the form of a specific fish oil extract.

In the study, 120 middle-aged women were split into two treatment groups. One group was given a concentrated fish oil extract, which provided a total of 1,050 mg of EPA and 150 mg of DHA. The second group was given a “placebo” pill that looked identical to the fish oil, but contained sunflower oil. The entire study spanned an eight week period.

Prior to the start of the trial, researchers conducted a battery of tests to determine the women’s level of “psychological distress”. Most of the women were deemed as suffering from mild-to-moderate depression. 24% of the women however met the criteria for major depression.

By the trial’s end, significant benefits were found in both the mild-to-moderate and the major depressives who were taking the specialized fish oil. No benefit was found for the sunflower oil group. One of the concluding comments by the researchers stated that, “The differences we observed between the two groups are noteworthy, especially considering that omega-3s have very few side effects and are beneficial to cardiovascular health.”

The Other Fatty Acid

In the first study I presented, EPA was the star. This next trial focused on the other omega-3 fatty acid in fish oil: DHA. This particular study was conducted to discover whether there is an ideal dosage of DHA for use in “major depressive disorder”. Here are some of the specifics of the experiment:

  • 35 depressed men and women participated. Roughly half of the group were men and the other half women. Their average age was 42.
  • These volunteers were divided into three test groups. The first received 1,000 mg of DHA per day. The second was given 2,000 mg. The last group was provided with 4,000 mg of DHA daily.
  • Success was measured by a 50% or greater reduction in the patients’ Hamilton-Depression Scale score. This test is frequently used by psychiatrists to help determine the magnitude of depression.
  • 83% of the 1,000 mg DHA group “got better”. 40% of the 2,000 mg DHA users improved. Quite shockingly, 0% of the 4,000 mg patients found a benefit!

This is a really fascinating study, in my opinion. First of all, both men and women were tested – which is a major plus. Secondly, high dosages of fish oil were used. Often times these sorts of studies use dosages that are smaller than what many nutritional experts would otherwise recommend. But the most important finding is that more is not necessarily better, with regard to fish oil and depression. In fact, it appears that less fish oil (DHA) is more effective!

Medical research is always a work in progress. When it comes to the connection between EPA, DHA and depression, there’s still much to be learned. But that doesn’t mean that we can’t benefit from what’s already been discovered. We can use what we know now and always modify our approach as new information becomes available. Heck, that’s what doctors and patients have been doing since the beginning of time. Why stop now?

Note: Please check out the “Comments & Updates” section of this blog – at the bottom of the page. You can find the latest research about this topic there!

Be well!


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Posted in Alternative Therapies, Mental Health, Nutritional Supplements

4 Comments & Updates to “Fish Oil for Depression”

  1. anne h Says:

    Love this – can you suggest a name brand? I have looked everywhere!
    Coming up with the same old same old.

  2. JP Says:

    Hi, Anne.

    There are many good fish oil products out there. Here are several brands that consistently pass independent quality tests:

    Country Life, Life Extension, Nordic Naturals, NSI (Vitacost), Solgar and Swanson.

    I wish you a happy and healthy Thanksgiving! 🙂

    Be well!


  3. JP Says:

    Updated 09/04/15:

    Nutrition. 2015 Oct;31(10):1247-54.

    The effect of 12-wk ω-3 fatty acid supplementation on in vivo thalamus glutathione concentration in patients “at risk” for major depression.

    OBJECTIVES: As life expectancy increases, the need to prevent major health disorders is clear. Depressive symptoms are common in older adults and are associated with cognitive decline and greater risk for transitioning to major depression. Oxidative stress may be implicated in the pathophysiology of major depression and can be measured in vivo using proton magnetic resonance spectroscopy via the neurometabolite glutathione (GSH). Evidence suggests ω-3 fatty acid (FA) supplementation may prevent depression and directly affect GSH concentration. The aim of this study was to examine the effect of ω-3 FA supplementation on in vivo GSH concentration in older adults at risk for depression.

    METHODS: Fifty-one older adults at risk for depression were randomized to receive either four 1000-mg ω-3 FA supplements daily (containing eicosapentaenoic acid 1200 mg plus docosahexaenoic acid 800 mg) or placebo (four 1000-mg paraffin oil placebo capsules daily) for 12 wk. Participants underwent magnetic resonance spectroscopy, as well as medical, neuropsychological, and self-report assessments at baseline and after 12 wk of supplementation. GSH was measured in the thalamus and calculated as a ratio to creatine. Depressive symptoms were measured using the Patient Health Questionnaire.

    RESULTS: Compared with the group given the ω-3 FA supplements, the placebo group had greater change in the GSH-to-creatine ratio in the thalamus (t = 2.00; P = 0.049) after the 12 wk intervention. This increase was in turn associated with a worsening of depressive symptoms (r = 0.43; P = 0.043).

    CONCLUSIONS: Depressive symptom severity in older adults appears to be associated with increased brain levels of GSH, a key marker of oxidative stress. Importantly, ω-3 FA supplementation may attenuate oxidative stress mechanisms, thereby offering benefits for depression prevention.

    Be well!


  4. JP Says:

    Updated 03/130/16:

    Transl Psychiatry. 2016 Mar 15;6:e756.

    Meta-analysis and meta-regression of omega-3 polyunsaturated fatty acid supplementation for major depressive disorder.

    Omega-3 polyunsaturated fatty acid (PUFA) supplementation has been proposed as (adjuvant) treatment for major depressive disorder (MDD). In the present meta-analysis, we pooled randomized placebo-controlled trials assessing the effects of omega-3 PUFA supplementation on depressive symptoms in MDD. Moreover, we performed meta-regression to test whether supplementation effects depended on eicosapentaenoic acid (EPA) or docosahexaenoic acid dose, their ratio, study duration, participants’ age, percentage antidepressant users, baseline MDD symptom severity, publication year and study quality. To limit heterogeneity, we only included studies in adult patients with MDD assessed using standardized clinical interviews, and excluded studies that specifically studied perinatal/perimenopausal or comorbid MDD. Our PubMED/EMBASE search resulted in 1955 articles, from which we included 13 studies providing 1233 participants. After taking potential publication bias into account, meta-analysis showed an overall beneficial effect of omega-3 PUFAs on depressive symptoms in MDD (standardized mean difference=0.398 (0.114-0.682), P=0.006, random-effects model). As an explanation for significant heterogeneity (I(2)=73.36, P<0.001), meta-regression showed that higher EPA dose (β=0.00037 (0.00009-0.00065), P=0.009), higher percentage antidepressant users (β=0.0058 (0.00017-0.01144), P=0.044) and earlier publication year (β=-0.0735 (-0.143 to 0.004), P=0.04) were significantly associated with better outcome for PUFA supplementation. Additional sensitivity analyses were performed. In conclusion, present meta-analysis suggested a beneficial overall effect of omega-3 PUFA supplementation in MDD patients, especially for higher doses of EPA and in participants taking antidepressants. Future precision medicine trials should establish whether possible interactions between EPA and antidepressants could provide targets to improve antidepressant response and its prediction. Furthermore, potential long-term biochemical side effects of high-dosed add-on EPA supplementation should be carefully monitored.

    Be well!


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