Supplement Forms/Alternate Names
- Docosahexaenoic Acid (DHA)
- Eicosapentaenoic Acid (EPA)
- Omega-3 Fatty Acids
- Omega-3 Oil(s)
Other Proposed Uses
- Alzheimer’s Disease
- Ankylosing Spondylitis
- Attention Deficit and Hyperactivity Disorder (ADHD)
- Bipolar Disorder (Manic-Depressive Illness)
- Borderline Personality Disorder
- Cardiac Arrhythmia
- Cancer Treatment Support
- Canker Sores
- Chronic Fatigue Syndrome
- Congestive Heart Failure
- Crohn's Disease
- Diabetic Neuropathy
- Dysmenorrhea (Menstrual Pain)
- Eczema (Prevention)
- Enhancing Memory and Mental Function
- HIV Support
- Kidney Stones
- Liver Disease
- Macular Degeneration
- Male Infertility
- Migraine Headaches
- Multiple Sclerosis
- Pregnancy Support (including postpartum depression)
- Prevention of Premature Birth
- Prostate Cancer Prevention
- Raynaud's Phenomenon
- Retinitis Pigmentosa
- Sickle-cell Anemia
- Strokes (Prevention)
- Surgery Support
- Ulcerative Colitis
- Undesired Weight Loss Caused by Cancer
Fish oil contains omega-3 fatty acids, one of the two main classes of essential fatty acids. ( Omega-6 fatty acids are the other main type.) Essential fatty acids are special fats that the body needs for optimum health.
Interest in the potential therapeutic benefits of omega-3 fatty acids began when studies of the Inuit (Eskimo) people found that, although their diets contain an enormous amount of fat from fish, seals, and whales, they seldom suffer heart attacks. This is presumably because those sources of fat are very high in omega-3 fatty acids.
Subsequent investigation found that the omega-3 fatty acids found in fish oil have various effects that tend to reduce risk of heart disease and strokes. However, research into whether use of fish oil actually prevents these diseases remains incomplete and somewhat inconsistent. In recognition of this, the FDA has allowed supplements containing fish oil or its constituents to carry a label that states: "Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease."
Fish oil has also shown promise as an anti-inflammatory treatment for conditions such as rheumatoid arthritis, menstrual pain, and lupus. In addition, it may be helpful for various psychiatric conditions.
There is no daily requirement for fish oil. However, a healthy diet should provide at least 5 g of essential fatty acids daily.
Typical dosages of fish oil are 3 g to 9 g daily, but this is not the upper limit. In one study, participants ingested 60 g daily.
Some manufacturers add vitamin E to fish oil capsules to keep the oil from becoming rancid. Another method is to remove all the oxygen from the capsule.
If possible, purchase fish oil products certified as free of significant levels of mercury, toxic organochlorines, and PCBs (see Safety Issues).
For several other conditions, the current balance of the evidence suggests that fish oil is not effective.
What Is the Scientific Evidence for Fish Oil?
Heart Disease Prevention
cardiovascular diseaseincreases increased
Regular use of fish oil may reduce the pain of menstrual cramps .
12 12 12
The explanation for the discrepancy may lie in the differences between the women studied. The first study involved women living in nursing homes, while the second studied healthier women living on their own. The latter group of women may have been better nourished and already received enough essential fatty acids in their diet.
Fish oil appears to be generally safe. The most common problem is fishy burps. However, there are some safety concerns to consider.
If you decide to use cod liver oil as your fish oil supplement, make sure you do not exceed the safe maximum intake of vitamin A and vitamin D . These vitamins are fat soluble, which means that excess amounts tend to build up in your body, possibly reaching toxic levels. The official maximum daily intake of vitamin A is 3,000 mcg for pregnant women as well as other adults. Look at the bottle label to determine how much vitamin A you are receiving. (It is less likely that you will get enough vitamin D to produce toxic effects.)
Interactions You Should Know About
- Reviewer: EBSCO CAM Review Board
- Review Date: 08/2013 -
- Update Date: 00/22/2014 -