12 Important Benefits of Fish Oil, Based on Science

12 Benefits of Taking Fish Oil
Fish oil is an excellent source of omega-3s, which is good for the heart and the brain. However, getting your omega-3s from fish is healthier. If you don’t eat fish, fish oil supplements are a good alternative.
Fish oil is one of the most commonly consumed dietary supplements.
It’s rich in omega-3 fatty acids, which are very important for your health.
If you don’t eat a lot of oily fish, taking a fish oil supplement could help you get enough omega-3 fatty acids.
It usually comes from oily fish such as herring, tuna, anchovies, and mackerel. However. it’s also sometimes produced from the livers of other fish, as is the case with cod liver oil.
The World Health Organization (WHO) recommends eating 1–2 portions of fish per week. This is because the omega-3 fatty acids in fish provide many health benefits, including protection against a number of diseases.
However, if you don’t eat 1–2 servings of fish per week, fish oil supplements can help you get enough omega-3s.
Around 30% of fish oil is made up of omega-3s, while the remaining 70% is made up of other fats. What’s more, fish oil usually contains some vitamin A and D.
It’s important to note that the types of omega-3s found in fish oil have greater health benefits than the omega-3s found in some plant sources.
The main types of omega-3s in fish oil are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), while the type found in plant sources is mainly alpha-linolenic acid (ALA).
Although ALA is an essential fatty acid, EPA and DHA have many more health benefits (1, 2).
It’s also important to get enough omega-3s because the Western diet has replaced a lot of omega-3s with other fats, such as omega-6s. This distorted ratio of fatty acids may contribute to numerous diseases (3, 4, 5, 6).
Your brain is made up of nearly 60% fat, and much of this fat is omega-3 fatty acids. Therefore, omega-3s are essential for typical brain function (26, 27).
In fact, some studies suggest that people with certain mental health conditions have lower omega-3 blood levels (28, 29).
Crystal HoshawTAKING FISH OIL
Peace of mind
Brain and nervous system health is super important to me. I've experienced anxiety throughout my life. In fact, it runs in my family, and so does Alzheimer’s. There’s a lot of great research out there that fish oil and the omega-3 fatty acids they contain support the brain, improve mental health, as well as help prevent a number of chronic diseases. I think the effects of fish oil are likely subtle and really going to show up long-term. It’s difficult to say whether I feel an acute effect of taking it, but I trust the evidence.
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Interestingly, research suggests that omega-3s can prevent the onset or improve the symptoms of some mental health conditions. For example, it can reduce the chances of psychotic disorders in those who are at risk (30, 31).
In addition, supplementing with fish oil in high doses may reduce some symptoms of both schizophrenia and bipolar disorder, though there is a lack of consistent data available. More study is needed in this area (31, 32).
Summary
Fish oil supplements may improve the symptoms of certain mental health conditions. This effect may be a result of increasing omega-3 fatty acid intake.
Like your brain, your eyes rely on omega-3 fats. Evidence shows that people who don’t get enough omega-3s have a greater risk of eye diseases (33, 34).
However, this positive effect was not found for dry eye disease in particular (35).
Furthermore, eye health begins to decline in old age, which can lead to age-related macular degeneration (AMD). Eating fish is linked to a reduced risk of AMD, but the results from fish oil supplements are less convincing (36, 37).
One older study found that consuming a high dose of fish oil for 19 weeks improved vision in people with AMD. However, this was a very small study (38).
Two larger studies in 2013 examined the combined effect of omega-3s and other nutrients on AMD. One study showed a positive effect, while the other found no effect. Therefore, the results are unclear (39, 40).
Summary
Eating fish may help prevent eye diseases. However, it’s unclear whether fish oil supplements have this same effect.
Because fish oil has anti-inflammatory properties, it may help treat conditions involving chronic inflammation (43).
For example, increased weight or stress can sometimes contribute to higher levels of inflammation.
In two older studies — one in people with obesity and one in people experiencing stress — fish oil was found to reduce the production and gene expression of inflammatory molecules called cytokines (44, 45).
Moreover, fish oil supplements can significantly reduce joint pain, stiffness, and medication needs in people with rheumatoid arthritis, which causes pain in the joints (46, 47).
While inflammatory bowel disease (IBD) is also triggered by inflammation, there is no clear evidence to suggest that fish oil improves its symptoms (48).
Therefore, it’s important to get enough omega-3s during pregnancy and while breastfeeding.
Taking fish oil supplements during these times may improve fetal brain development. However, it’s unclear whether learning or IQ will also be improved (53, 54).
Taking fish oil supplements during pregnancy and breastfeeding may also improve infant visual development and help reduce the risk of allergies (55).
Summary
Omega-3 fatty acids are vital for an infant’s early growth and development. Fish oil supplements in pregnant people or infants may improve hand-eye coordination, although their effect on learning and IQ is unclear.
In one study, researchers found that omega-3 supplementation increased BMD in women with no symptoms or bone pain, but it did not appear to do so in women with osteoporosis. More research is needed (81).
A number of small, older studies suggest that fish oil supplements reduce markers of bone breakdown, which may prevent bone disease (82).
Dosage
EPA and DHA dosage recommendations vary according to your age and health.
For most adults, WHO recommends a daily intake of 1.1–1.6 grams (1,100–1,600 mg) of omega-3 fatty acids. However, it may be necessary to increase the dosage if you are pregnant, nursing, or at risk of heart disease (84).
Form
Fish oil supplements come in a number of forms, including ethyl esters, triglycerides, reformed triglycerides, free fatty acids, and phospholipids.
Your body doesn’t absorb ethyl esters as well as other forms, so try to choose a fish oil supplement that comes in one of the other listed forms (85).
Concentration
Many supplements contain up to 1,000 mg of fish oil per serving but only 300 mg of EPA and DHA.
Read the label and choose a supplement that contains at least 500 mg of EPA and DHA per 1,000 mg of fish oil.
Purity
Some fish oil supplements may not contain the ingredients that they say they do (86).
To avoid these products, choose a supplement that is third-party tested or has a seal of purity from the Global Organization for EPA and DHA Omega-3s (GOED) (87).
Freshness
Omega-3 fatty acids are prone to oxidation, which makes them go rancid.
To avoid this, you can choose a supplement that contains an antioxidant, such as vitamin E. Also, keep your supplements away from light — ideally in the refrigerator.
Don’t use a fish oil supplement that has a rancid smell or is out of date.
Sustainability
Choose a fish oil supplement that has a sustainability certification, such as from the Marine Stewardship Council (MSC) or the Environmental Defense Fund.
The production of fish oil from anchovies and similar small fish is more sustainable than that from large fish.