The golden, egg-shaped capsules that we typically recognize as fish oil supplements have gained widespread popularity among health seekers. Found in the tissues of oily, cold-water fish, the oil is a rich source of omega-3 fatty acids, which are essential for many vital functions in the body, including brain function, muscle activity, and normal growth and development.
The benefits of fish oil are thought to include the alleviation of inflammation, protection against heart disease and certain cancers, and support for cognitive function, among other advantages. Yet the scientific opinion behind fish oil supplements is contradictory, with some studies supporting its positive effects and other studies finding neutral or even adverse effects from fish oil supplements.[1, 2]
Is fish oil good for you? There is much evidence to support that it is beneficial and safe to consume when it comes from a high-quality, organic source. And, as outlined later in this article, fish oil side effects are generally quite minor. If you are wondering what fish oil is good for, or how much fish oil per day is necessary to achieve its potential benefits, read on.
Top Fish Oil Benefits
- Beautifies Skin and Hair
- Supports Heart Health
- Bolsters Brain Health
- Reduces Inflammation
- Strengthens the Immune System
- Supports Eye Health
- Cancer Prevention
Fish oil gets its benefits from its high concentration of omega-3 fatty acids, which support general health and well-being in many ways. The two types of omega-3 fatty acids found in fish oil that are powerhouses for health are docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Essential to heart and brain health, DHA and EPA from fish oil can play a role in everyday wellness, particularly when combined with healthy body weight and regular exercise.
Beautifies Skin and Hair
Fish oil may help support healthy skin and hair. Deficiencies of DHA and EPA in the diet can lead to dry, irritated skin, as well as dandruff. While fish oil may help maintain skin moisture and support hair growth, more research is necessary to back these claims. Some small studies link increased fish oil consumption with a reduction in the symptoms of eczema, perhaps due to its anti-inflammatory properties.
Supports Heart Health
The consumption of fish oil, whether in food or supplements, provides nutrients that support cardiovascular health. One systematic review of the scientific literature found that increased fish oil consumption reduces the rate of adverse cardiac outcomes such as heart attack and stroke. The evidence is mixed, however, and some large studies have found that omega-3 supplements have no measurable effect on cardiovascular risk factors.
Although more research is needed to fully understand the entirety of the situation, researchers agree that omega-3 fatty acids like the ones found in fish oil are necessary to many aspects of heart health. Some studies support the benefits of fish oil to promote normal blood pressure, especially in people with moderate to severe hypertension. The omega-3s in fish oil can also reduce high levels of triglycerides, another risk factor for heart disease. Because the omega-3s in fish oil help prevent platelets from clumping, fish oil may reduce the risk of a blood clot. Moreover, researchers have seen a reduction of total cholesterol — as well as an increase in high-density lipoprotein (HDL) cholesterol, or "good" cholesterol — among people who increase their consumption of fish oil.
Bolsters Brain Health
The relationship between the omega-3 fatty acids found in fish oil and brain health is an intriguing subject for researchers — especially when you consider that somewhere between 5 to 10 percent of the mass of the human brain is made up of DHA omega-3 fatty acid. DHA is necessary for optimal brain health and cognitive function at all stages of life, from infants and children to adults and the elderly.
Researchers believe that DHA plays a key role in neural signaling and helps our brains to work faster. A deficiency of DHA in the body has been associated with deficits in learning and cognitive function, which has led many researchers to explore fish oil as an elixir to help the brain function at peak performance.
Although more research is needed, scientific interest in fish oil for brain health revolves around conditions such as Alzheimer's disease and attention-deficit/hyperactivity disorder (ADHD), as well as depression and other mental health conditions. One review of the literature found that omega-3 fatty acids from fish oil have a preventive effect on mood and anxiety disorders.
The omega-3s in fish oil have natural anti-inflammatory properties. In normal healing, inflammation is the body's reaction to infection and a necessary part of the immune system. However, when inflammation does not subside, or when it exists without the presence of an infection, it can have detrimental effects on the body in many ways. The ability of omega-3 fatty acids to reduce inflammation means that fish oil may help with the symptoms of various autoimmune disorders — including rheumatoid arthritis, inflammatory bowel disease, asthma, and allergies. Yet the scientific evidence is early on just how effective fish oil is for chronic disorders like these.
Strengthens the Immune System
Fish oil may also have benefits for people with compromised immune systems. A 2013 study found that DHA-rich fish oil enhances the activity of B cells, which are white blood cells that help make antibodies for a healthy immune response.
Supports Eye Health
Some studies show that fish oil may help to relieve the symptoms of dry eye, a condition in which the eye cannot maintain its protective coating of tears. The omega-3 fatty acids in fish oil may improve the function of the glands in the eyes that produce tears, thereby helping to reduce irritation from dry eye.
The scientific evidence is mixed concerning the benefits of fish oil for age-related macular degeneration, which involves the deterioration of the macula (the central portion of the retina) and is the leading cause of vision loss in the U.S. While some studies support the use of high-dose fish oil for macular degeneration, other studies find that fish oil supplements do not alter the progression of the disease.
Aids in Cancer Prevention
The omega-3 fatty acids in fish oil may protect from certain cancers, such as breast and colorectal cancer. Researchers have found that fish oil can reduce cancer-causing compounds, such as prostaglandin E2 in the colon, which may trigger colon cancer. And various studies associate increased consumption of marine omega-3 fats with a reduced risk of breast cancer.
Some studies, however, link high-dose fish oil consumption with an increased risk of prostate cancer. Authors involved in these studies caution men against taking "mega" doses of fish oil supplements for this reason.
Best Sources of Fish Oil
If fatty fish is not a regular part of your diet, you can take fish oil supplements to reap the omega-3 benefits. Just make sure your fish oil comes from high-quality, organic sources. Here's a guide to finding them.
- Alaskan wild salmon
- Black cod
Cod liver oil, which is made only from the liver of cod, is also a good source of the omega-3 fatty acids DHA and EPA.
Vegans can turn to plant-based sources of omega-3 fatty acids, which may provide similar benefits to marine sources. Plant-based sources include:
- Chia seeds
- Flaxseed oil
- Hemp seeds
- Canola oil
- Omega-3 supplements derived from algae
In most cases, the type of omega-3 fatty acid available in plant-based sources is alpha-linolenic acid (ALA), which the body can convert to the DHA and EPA needed for vital functions. The body's conversion rate is slow, however, so plant-based sources may not yield as high a concentration of DHA and EPA as marine sources. One exception in the plant world is algae, which does contain bioavailable DHA and EPA.
Which Is Best: Food or Supplement?
Our bodies evolved to eat whole food rather than the isolated compounds and nutrients found in supplements. But because most fatty fish contains high levels of mercury, relying on whole fish for omega-3s may expose the body to harmful amounts of mercury. Avoiding mercury is important for everyone, but especially for women during pregnancy and breastfeeding. For this reason, many people turn to fish oil supplements, which do not contain even trace levels of mercury.
If you prefer to get your marine omega-3s from whole food and don't subscribe to a plant-only diet, stick to wild salmon, sardines, anchovies, and herring, which tend to be low in mercury and other contaminants. Bivalves such as mussels, clams, and oysters are also a very good, low-mercury source of beneficial omega-3s.
How Much Fish Oil Per Day?
Eating fatty, low-mercury fish — such as wild salmon, sardines, anchovies, or herring — twice a week is a good way to get your dietary allowance of fish oil.
|Daily DHA/EPA Recommendation||Dosage|
|Pregnant/breastfeeding women||Up to 700 mg|
Whether you get it from supplements or whole foods, 250–500 milligrams daily of combined DHA and EPA is generally enough for adults to maintain overall health. Pregnant and breastfeeding women need an additional 200 milligrams per day, while a total of 50–100 milligrams per day is enough for an infant or child.
If you are taking a fish oil supplement for a particular health reason, you may take anywhere from 200–3,000 milligrams of combined DHA and EPA per day, depending on the health concern.
How much fish oil is considered safe? The American Heart Association recommends not exceeding three grams of fish oil supplement daily. Always consult with your doctor or healthcare provider before beginning a supplement regimen.
Side Effects of Fish Oil
The side effects of fish oil are usually quite mild, and fish oil is generally safe to consume. Side effects from fish oil supplements can include:
To avoid these side effects, be sure to take fish oil with meals rather than on its own.
Consuming extremely high doses of fish oil (over three grams) can have a side effect of bleeding (e.g., nosebleeds) and may increase the risk of hemorrhagic stroke.
Are There Risks to Taking Fish Oil?
When taken at the recommended doses, fish oil carries only minor risks (see side effects above). There is some evidence that high-dose fish oil may increase the risk of prostate cancer; however, other studies find that fish oil may actually help prevent the same type of cancer, and more research is needed.
Should You Take a Supplement?
Scientific opinion about fish oil tends to flip-flop just as much as fish do themselves. Yet we still have a raft of good evidence on the benefits of fish oil for a range of health issues. Some of the most compelling studies show that it can reduce high blood levels of triglycerides for heart health, lower the risk of breast and colon cancer, and alleviate mood and anxiety disorders.
Fish oil supplements may be the best way to get a serving of fish oil that is high enough to be effective for your particular health concern. If you decide to take a supplement, you can take fish oil in the form of capsules, liquid, or pills (be sure to take organic fish oil, and always discuss the regimen with your healthcare provider). Alternatively, plant-based omega-3 supplements offer the same beneficial DHA and EPA fatty acids as marine sources do for optimal health.
- Ghasemi Fard S, Wang F, Sinclair AJ, Elliott G, Turchini GM. "How does high DHA fish oil affect health? A systematic review of evidence." Crit Rev Food Sci Nutr. 2018 Mar 1:1-44.
- Alexander W. "Prostate cancer risk and omega-3 Fatty Acid intake from fish oil: a closer look at media messages versus research findings." PT. 2013 Sep; 38(9): 561–564.
- Bath‐Hextall FJ, Jenkinson C, Humphreys R, Williams HC. "Dietary supplements for established atopic eczema." Cochrane Database of Systematic Reviews 2012, Issue 2. Art. No.: CD005205.
- Wang C, Harris WS, Chung M, Lichtenstein AH, Balk EM, Kupelnick B, Jordan HS, Lau J. "n-3 Fatty acids from fish or fish-oil supplements, but not alpha-linolenic acid, benefit cardiovascular disease outcomes in primary- and secondary-prevention studies: a systematic review." Am J Clin Nutr. 2006 Jul;84(1):5-17.
- "n–3 Fatty Acids in Patients with Multiple Cardiovascular Risk Factors." N Engl J Med 2013 May; 368:1800-1808.
- National Center for Biotechnology Information. "Does fish oil lower blood pressure? A meta-analysis of controlled trials."
- McKenney JM, Sica D. "Prescription omega-3 fatty acids for the treatment of hypertriglyceridemia." Am J Health Syst Pharm. 2007 Mar 15;64(6):595-605. Review.
- Brinson BE, Miller S. "Fish oil: what is the role in cardiovascular health?" J Pharm Pract. 2012 Feb;25(1):69-74.
- Kuan-Pin Su, Yutaka Matsuoka, Chi-Un Pae. "Omega-3 Polyunsaturated Fatty Acids in Prevention of Mood and Anxiety Disorders." Clin Psychopharmacol Neurosci. 2015 Aug; 13(2): 129–137.
- Calder PC. "Marine omega-3 fatty acids and inflammatory processes: Effects, mechanisms and clinical relevance." Biochim Biophys Acta. 2015 Apr;1851(4):469-84.
- Gurzell EA, Teague H, Harris M, Clinthorne J, Shaikh SR, Fenton JI. "DHA-enriched fish oil targets B cell lipid microdomains and enhances ex vivo and in vivo B cell function." J Leukoc Biol. 2013 Apr;93(4):463-70.
- Vimont C. "Can fish oil help dry eye?" American Academy of Ophthalmology. 2016 Oct.
- Georgiou T, Prokopiou E. "The New Era of Omega-3 Fatty Acids Supplementation: Therapeutic Effects on Dry Age-Related Macular Degeneration." J Stem Cells. 2015;10(3):205-15.
- Fabian C, Kimler B, Hursting D. "Omega-3 fatty acids for breast cancer prevention and survivorship." Breast Cancer Res. 2015 May; 17(1): 62.
- Brasky TM, Darke AK, Song X, et al. "Plasma phospholipid fatty acids and prostate cancer risk in the SELECT trial." J Natl Cancer Inst. 2013 Jul 10.
- European Food Safety Authority. "Scientific Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA)." 2012 July.
- Greenberg JA, Bell SJ, Van Ausdal W. "Omega-3 Fatty Acid Supplementation During Pregnancy." Rev Obstet Gynecol. 2008 Fall; 1(4): 162–169.
- Augustsson K, Michaud DS, Rimm EB, Leitzmann MF, Stampfer MJ, Willett WC, Giovannucci E. "A prospective study of intake of fish and marine fatty acids and prostate cancer." Cancer Epidemiol Biomarkers Prev. 2003 Jan;12(1):64-7.
†Results may vary. Information and statements made are for education purposes and are not intended to replace the advice of your doctor. Global Healing Center does not dispense medical advice, prescribe, or diagnose illness. The views and nutritional advice expressed by Global Healing Center are not intended to be a substitute for conventional medical service. If you have a severe medical condition or health concern, see your physician.