13 Benefits of Taking Fish Oil
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.
Here are 13 health benefits of fish oil.
What Is Fish Oil?
Fish oil is the fat or oil that’s extracted from fish tissue.
It usually comes from oily fish, such as herring, tuna, anchovies, and mackerel. Yet it’s 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 omega-3s in fish oil are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), while the omega-3 in plant sources is mainly alpha-linolenic acid (ALA).
Although ALA is an essential fatty acid, EPA and DHA have many more health benefits (1Trusted Source, 2Trusted Source).
It’s also important to get enough omega-3s because the Western diet has replaced a lot of omega-3s with other fats like omega-6s. This distorted ratio of fatty acids may contribute to numerous diseases (3Trusted Source, 4Trusted Source, 5Trusted Source, 6Trusted Source).
1. May Support Heart Health
Heart disease is the leading cause of death worldwide (7Trusted Source).
Studies show that people who eat a lot of fish have much lower rates of heart disease (8Trusted Source, 9Trusted Source, 10Trusted Source).
Multiple risk factors for heart disease appear to be reduced by consumption of fish or fish oil. The benefits of fish oil for heart health include:
Cholesterol levels: It can increase levels of “good” HDL cholesterol. However, it does not appear to
reduce levels of “bad” LDL cholesterol (11Trusted Source, 12Trusted Source, 13Trusted Source, 14Trusted Source, 15Trusted Source, 16Trusted Source).Triglycerides: It can lower triglycerides by about 15–30% (16Trusted Source, 17Trusted Source, 18Trusted Source).
Blood pressure: Even in small doses, it helps reduce blood pressure in people with elevated levels (19Trusted Source, 20Trusted Source, 21Trusted Source).
Plaque: It may prevent the plaques that cause your arteries to harden, as well as make arterial plaques more stable and safer in those who already have them (22Trusted Source, 23Trusted Source, 24Trusted Source).
Fatal arrhythmias: In people who are at risk, it may reduce fatal arrhythmia events. Arrhythmias are abnormal heart rhythms that can cause heart attacks in certain cases (25Trusted Source).
Although fish oil supplements can improve many of the risk factors for heart disease, there is no clear evidence that it can prevent heart attacks or strokes (26Trusted Source).
SUMMARY
Fish oil supplements may reduce some of the
risks associated with heart disease. However, there is no clear evidence that
it can prevent heart attacks or strokes.
2. May Help Treat Certain Mental Disorders
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 normal brain function (27Trusted Source, 28Trusted Source).
In fact, some studies suggest that people with certain mental disorders have lower omega-3 blood levels (29Trusted Source, 30Trusted Source, 31Trusted Source).
Interestingly, research suggests that fish oil supplements can prevent the onset or improve the symptoms of some mental disorders. For example, it can reduce the chances of psychotic disorders in those who are at risk (32Trusted Source, 33Trusted Source).
In addition, supplementing with fish oil in high doses may reduce some symptoms of both schizophrenia and bipolar disorder (33Trusted Source, 34Trusted Source, 35Trusted Source, 36Trusted Source, 37Trusted Source, 38Trusted Source).
SUMMARY
Fish oil supplements may improve the symptoms
of certain psychiatric disorders. This effect may be a result of increasing
omega-3 fatty acid intake.
3. May Aid Weight Loss
Obesity is defined as having a body mass index (BMI) greater than 30. Globally, about 39% of adults are overweight, while 13% are obese. The numbers are even higher in high-income countries like the US (39Trusted Source).
Obesity can significantly increase your risk of other diseases, including heart disease, type 2 diabetes, and cancer (40Trusted Source, 41Trusted Source, 42Trusted Source).
Fish oil supplements may improve body composition and risk factors for heart disease in obese people (43Trusted Source, 44Trusted Source, 45Trusted Source).
Furthermore, some studies indicate that fish oil supplements, in combination with diet or exercise, can help you lose weight (43Trusted Source, 46Trusted Source).
However, not all studies found the same effect (47Trusted Source, 48Trusted Source).
One analysis of 21 studies notes that fish oil supplements didn’t significantly reduce weight in obese individuals but did reduce waist circumference and waist-to-hip ratio (49Trusted Source).
SUMMARY
Fish oil supplements may help reduce waist
circumference, as well as aid weight loss when combined with diet or exercise.
4. May Support Eye Health
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 (50Trusted Source, 51Trusted Source).
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 on fish oil supplements are less convincing (52Trusted Source, 53Trusted Source).
One study found that consuming a high dose of fish oil for 19 weeks improved vision in all AMD patients. However, this was a very small study (54).
Two larger studies examined the combined effect of omega-3s and other nutrients on AMD. One study showed a positive effect, while the other exhibited no effect. Therefore, the results are unclear (55Trusted Source, 56Trusted Source).
SUMMARY
Eating fish may help prevent eye diseases.
However, it’s unclear whether fish oil supplements have this same effect.
5. May Reduce Inflammation
Inflammation is your immune system’s way of fighting infection and treating injuries.
However, chronic inflammation is associated with serious illnesses, such as obesity, diabetes, depression, and heart disease (57Trusted Source, 58Trusted Source, 59Trusted Source).
Reducing inflammation can help treat symptoms of these diseases.
Because fish oil has anti-inflammatory properties, it may help treat conditions involving chronic inflammation (60Trusted Source).
For example, in stressed and obese individuals, fish oil can reduce the production and gene expression of inflammatory molecules called cytokines (61Trusted Source, 62Trusted Source).
Moreover, fish oil supplements can significantly reduce joint pain, stiffness, and medication needs in people with rheumatoid arthritis, which causes painful joints (63Trusted Source, 64Trusted Source).
While inflammatory bowel disease (IBD) is also triggered by inflammation, there is no clear evidence to suggest whether fish oil improves its symptoms (65Trusted Source, 66Trusted Source).
SUMMARY
Fish oil has strong anti-inflammatory effects
and can help reduce symptoms of inflammatory diseases, especially rheumatoid
arthritis.
6. May Support Healthy Skin
Your skin is the largest organ in your body, and it contains a lot of omega-3 fatty acids (67Trusted Source).
Skin health can decline throughout your life, especially during old age or after too much sun exposure.
That said, there are a number of skin disorders that may benefit from fish oil supplements, including psoriasis and dermatitis (68Trusted Source, 69Trusted Source, 70Trusted Source).
SUMMARY
Your skin can become damaged by aging or too
much sun exposure. Fish oil supplements may help maintain healthy skin.
7. May Support Pregnancy and Early Life
Omega-3s are essential for early growth and development (71Trusted Source).
Therefore, it’s important for mothers to get enough omega-3s during pregnancy and while breastfeeding.
Fish oil supplements in pregnant and breastfeeding mothers may improve hand-eye coordination in infants. However, it’s unclear whether learning or IQ are improved (72Trusted Source, 73Trusted Source, 74Trusted Source, 75Trusted Source, 76Trusted Source).
Taking fish oil supplements during pregnancy and breastfeeding may also improve infant visual development and help reduce the risk of allergies (77Trusted Source, 78Trusted Source).
SUMMARY
Omega-3 fatty acids are vital for an infant’s
early growth and development. Fish oil supplements in mothers or infants may
improve hand-eye coordination, although their effect on learning and IQ is
unclear.
8. May Reduce Liver Fat
Your liver processes most of the fat in your body and can play a role in weight gain.
Liver disease is increasingly common — particularly non-alcoholic fatty liver disease (NAFLD), in which fat accumulates in your liver (79Trusted Source).
Fish oil supplements can improve liver function and inflammation, which may help reduce symptoms of NAFLD and the amount of fat in your liver (80Trusted Source, 81Trusted Source, 82Trusted Source, 83Trusted Source).
SUMMARY
Liver disease is common in obese individuals.
Fish oil supplements may help reduce fat in your
liver and symptoms of non-alcoholic fatty liver disease.
9. May Improve Symptoms of Depression
Depression is expected to become the second-largest cause of illness by 2030 (84Trusted Source).
Interestingly, people with major depression appear to have lower blood levels of omega-3s (29Trusted Source, 85Trusted Source, 86Trusted Source).
Studies show that fish oil and omega-3 supplements may improve symptoms of depression (87Trusted Source, 88, 89).
Moreover, some studies have shown that oils rich in EPA help reduce depressive symptoms more than DHA (90Trusted Source, 91Trusted Source).
SUMMARY
Fish oil supplements — especially EPA-rich
ones — may help improve symptoms of depression.
10. May Improve Attention and Hyperactivity in Children
A number of behavioral disorders in children, such as attention deficit hyperactivity disorder (ADHD), involve hyperactivity and inattention.
Given that omega-3s make up a significant proportion of the brain, getting enough of them may be important for preventing behavioral disorders in early life (92).
Fish oil supplements may improve perceived hyperactivity, inattention, impulsiveness, and aggression in children. This may benefit early life learning (93, 94, 95, 96Trusted Source).
SUMMARY
Behavioral disorders in children can
interfere with learning and development. Fish oil supplements have been shown
to help reduce hyperactivity, inattention, and other negative behaviors.
11. May Help Prevent Symptoms of Mental Decline
As you age, your brain function slows down, and your risk of Alzheimer’s disease increases.
People who eat more fish tend to experience a slower decline in brain function in old age (97Trusted Source, 98Trusted Source, 99Trusted Source).
However, studies on fish oil supplements in older adults haven’t provided clear evidence that they can slow the decline of brain function (100Trusted Source, 101Trusted Source).
Nevertheless, some very small studies have shown that fish oil may improve memory in healthy, older adults (102Trusted Source, 103).
SUMMARY
People who eat more fish have slower
age-related mental decline. However, it’s unclear if fish oil supplements can
prevent or improve mental decline in older adults.
12. May Improve Asthma Symptoms and Allergy Risk
Asthma, which can cause swelling in the lungs and shortness of breath, is becoming much more common in infants.
A number of studies show that fish oil may reduce asthma symptoms, especially in early life (104Trusted Source, 105Trusted Source, 106Trusted Source, 107Trusted Source).
In one review in nearly 100,000 people, a mother’s fish or omega-3 intake was found to reduce the risk of asthma in children by 24–29% (108Trusted Source).
Furthermore, fish oil supplements in pregnant mothers may reduce the risk of allergies in infants (109).
SUMMARY
A higher intake of fish and fish oil during
pregnancy may reduce the risk of childhood asthma and allergies.
13. May Improve Bone Health
During old age, bones can begin to lose their essential minerals, making them more likely to break. This can lead to conditions like osteoporosis and osteoarthritis.
Calcium and vitamin D are very important for bone health, but some studies suggest that omega-3 fatty acids can also be beneficial.
People with higher omega-3 intakes and blood levels may have better bone mineral density (BMD) (110Trusted Source, 111Trusted Source, 112Trusted Source).
However, it’s unclear whether fish oil supplements improve BMD (113Trusted Source, 114Trusted Source).
A number of small studies suggest that fish oil supplements reduce markers of bone breakdown, which may prevent bone disease (115Trusted Source).
SUMMARY
Higher omega-3 intake is associated with
higher bone density, which could help prevent bone disease. However, it’s
unclear whether fish oil supplements are beneficial.
How to Supplement
If you do not eat 1–2 portions of oily fish per week, you may want to consider taking a fish oil supplement.
Below is a list of things to consider when taking a fish oil supplement:
Dosage
EPA and DHA dosage recommendations vary depending on your age and health.
WHO recommends a daily intake of 0.2–0.5 grams (200–500 mg) of combined EPA and DHA. However, it may be necessary to increase the dosage if you are pregnant, nursing, or at risk of heart disease (116Trusted Source).
Choose a fish oil supplement that provides at least 0.3 grams (300 mg) of EPA and DHA per serving.
Form
Fish oil supplements come in a number of forms, including ethyl esters (EE), triglycerides (TG), reformed triglycerides (rTG), free fatty acids (FFA) and phospholipids (PL).
Your body doesn’t absorb ethyl esters as well as others, so try to choose a fish oil supplement that comes in one of the other listed forms (117Trusted Source).
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
A number of fish oil supplements don’t contain what they say they do (118Trusted Source).
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).
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.
Timing
Other dietary fats help your absorption of omega-3 fatty acids (119Trusted Source).
Therefore, it’s best to take your fish oil supplement with a meal that contains fat.
SUMMARY
When reading fish oil labels, be sure to
choose a supplement with a high concentration of EPA and DHA and that has
purity and sustainability certifications.
The Bottom Line
Omega-3s contribute to normal brain and eye development. They fight inflammation and may help prevent heart disease and a decline in brain function.
As fish oil contains a lot of omega-3s, those at risk of these disorders can benefit from taking it.
However, eating whole foods is almost always better than taking supplements, and eating two portions of oily fish per week can provide you with enough omega-3s.
In fact, fish is as effective as fish oil — if not more so — at preventing many diseases.
That said, fish oil supplements are a good alternative if you don’t eat fish.
