Fish Oil Supplements: Sound Science or Mostly Hype?

Jul 5, 2014

By Joseph Brownstein

Among the many nutrition supplements trumpeted for potential health benefits, fish oil supplements have been among the most ballyhooed. But as the research on fish oil rolls in, it’s unclear whether the supplements provide all the touted benefits, or are as harmless as claimed.

Some of the possible benefits of fish oil that appeared in early studies of the supplement seem to have vanished. Along with the difficulty of isolating the effects of a single nutrient, it’s possible that those early studies had small sample sizes, or participants who were truly deficient in the nutrient. Since then, long-term studies have revealed potential harms from taking fish oil unnecessarily.

Fish oil supplements contain several vitamins and two significant omega-3 fatty acids, called eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). While these nutrients are important, like many vitamins, many people get sufficient amounts from diet. These fatty acids are found in a number of fish, so it is often recommended to get proper doses by eating oily fish twice a week.

Additionally, the amount of these fatty acids in a supplement can vary, so it is important to check the label. There are risks and benefits to the supplements, so it’s important to speak with your physician when deciding whether you are likely to benefit from taking them.

1. Heart health

When it comes to heart disease, eating fish is recommended as a heart-healthy protein, to substitute in place of red meat.

There is strong evidence for the potential of fish oil supplements to help in lowering triglycerides, which are associated with heart disease, as well as to lower the risk of heart attack.

But although fish oil supplements may have benefits for people at risk of heart problems, their benefit has been strongly questioned for healthy people, as high levels of omega-3 intake been linked with increased risk for stroke. High levels may also interfere with some medications, such as blood thinners, according to the National Institutes of Health.

2. Brain health

The omega-3 fatty acid DHA is found in both the gray and white matter of the brain, and is an important nutrient in early development, which is why there have been efforts to supplement child foods with it, whether it be the mother who breast-feeds or infant formula.

But taking DHA supplements has not shown clear benefits at the other end of life, where studies have been done to see if the compound may help people maintain cognitive function as they age. Although a few studies have shown benefits in reaching certain endpoints, such as maintaining brain size, there has not been a demonstration that DHA accomplishes the overall goal of helping prevent Alzheimer’s.

A June 2012 study published by the Cochrane Collaboration, a group that looks at the studies done on a topic to help make decisions for medical practitioners, found no benefit from fish oil supplements for cognitively healthy older people, but the authors said longer studies would be necessary to come to a firmer conclusion.

3. Autoimmune disease

DHA has long been studied in relation to immune function. As far back as the 1970s, the compound was found to play a role in the immune system and it was thought to possibly benefit patients with autoimmune diseases, such as multiple sclerosis, in which the immune system is overactive. Since then, DHA has been tested in people with other autoimmune diseases, such as rheumatoid arthritis.

16 comments on “Fish Oil Supplements: Sound Science or Mostly Hype?

  • Fish oil supplements are also promoted locally as having pain relieving properties. I noticed that this was not even mentioned in the article as it’s so wanting in any form of evidence.

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  • My better half who suffers from arthritis in some joints, swears salmon oil provides the necessary lubrication to relieve pain and discomfort. She went off it a few times and the pain returned, went back on and its gone. Ok, not a very scientific study, or even maybe the placebo effect, the fact she feels no more pain makes it all worthwhile. jcw

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  • That’s really interesting because I was going to supply anecdotal evidence as well ( though with evidence to the contrary.)

    I’ve suffered from pain from a heel spur for many years. I take anti inflamatory medication for this and it’s fairly effective. In addition, I’ve been taking a dietary supplement of fish oil capsules as I thought omega 3 would be a worthy addition to my diet. When these capsules began to be marketed as pain killers, I discontinued in order to put it to the test. No difference! Not a jot!

    On the other hand, if I miss my regular dose of anti inflamatory, my heel begins to hurt in no time. I know the pain from a heel spur is supposed to go after a few months but for some reason mine has kept on regardless of treatment.

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  • Another anecdotal evidence:

    I took fish oil supplement religiously for one year. My “S. Triglycerides” went down from 156 to 97. There was no other significant change to diet or exercise in my lifestyle. No other number (LDL, HDL, VLDL etc.) had any significant changes within that one year period. I am a “strict” vegetarian – absolutely no meat, hardly any eggs, but no restriction on diary products.

    Unfortunately, I had bought the supplements from Costco. That means I have enough capsules to last another year. I plan to stop it for a year after that and see if there is any changes in my Triglycerides number.

    My example does indeed seem to support the following statement in the article: “There is strong evidence for the potential of fish oil supplements to help in lowering triglycerides.”

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  • It’s not the miracle that some claim but I do believe it’s good for you. A person should be able to get all they need if they include oily fish like sardines, anchovies, salmon etc in their diets but that may not be to everyones personal tastes

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  • After the war, when diet was particularly poor in the UK, all children, me included. were given a dietry supplement of cod liver oil, probably the worst torture imposed on little children by a government since King Herod’s time. Our poor mothers would beg, cajole, threaten, plead and bribe us to take it, mostly without success. So, it appears, it was probably all a waste of time?

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  • My mother forced cod liver oil on us as children up until the age of 12 or so. She is Norwegian and it was practically a tradition to give all children cod liver oil. I agree with you – it was torture, even for fish-loving folks like us.

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  • 9
    alaskansee says:

    “Another anecdotal evidence”, oh no it’s not.

    It is important to understand that your story is scientifically and literally useless. Unless you were part of a monitored double blind study no one including yourself should draw any conclusions from it. You just can’t be sure enough for any comment. Safety first.

    This article is about needing evidence, you do not have any.

    It is always disappointing to see commenters mistaking feelings and suspicions as reason or science. That’s what we’re here for.

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  • Fish Oil (Omega 3’s..etc) has also been long touted for fitness and body builders use are helping muscle repair and growth. No mention above?

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  • 11
    NonyaBizness says:

    Why would they do a double blind study when did this little experiment to see if it benefited them and nobody else. They didn’t do it to prove to anyone that this oil didn’t work.
    There’s nothing worse then know-it-alls.

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  • I suffered from heel pain myself for over a year before going to see my doctor. Thought I was just getting old. But seems I was suffering from plantar fasciitis and was prescribed Nexproxen for two months. The doc told me it could take up to a year to heal and also the need to wear proper footwear was important. The best advice I got was to invest in a pair of running shoes and wear them whenever possible. You wont believe the number of functions I’ve been in my Nikes. But now eight months down the line and pretty much zero pain, and defiantly no hash stabs when I get out of bed.

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  • Actually, by its very definition, the evidence rmanoj gives is precisely anecdotal, which is why I’m guessing he/she cites it at the very beginning, because they’re not trying to pass it off as scientific evidence. And while not scientific it’s certainly not “useless” as a comment on a post about fish oil supplements.

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  • Derek, fish oil can be beneficial for a lot of things, but muscle repair and growth, to my knowledge, are not among those things. Mayo Clinic has graded fish oil with an “A” (Strong scientific evidence for this use) for the following disease states:

    • Coronary Heart Disease

    • High Blood Pressure

    • Hyperlipidemia (triglyceride lowering)

    • Rheumatoid arthritis

    • Secondary cardiovascular disease prevention (fish oil / EPA plus DHA)

    See the link below for details on how fish oil may benefit the above:


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  • Thanks Steve,

    Your right it’s great for the heart and the other things you list, but the Body Building World always mention it in the top list of supplements to take for weight training (for those same benefits you list and more, arguably margional benefits).

    Quote from (studies are in the footnote of article):

    “Results: As would be expected the corn oil had no effect on either muscle synthesis or anabolic signalling. Omega-3 supplementation did not impact fasted muscle protein synthesis levels but did enhance muscle protein synthesis after the amino acid/insulin infusion from 0.009 above basal values to 0.031 above basal values”

    See more at:

    I may of misguided the actual benefit of it in my first comment so apologies (repair/build,); those are more suited to a creatine supplement, but Omega3 can also help with inflammation caused by heavy training, reducing injuries and a little fat loss.


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