Natural Standard® Patient Monograph, Copyright © 2014 (www.naturalstandard.com). All Rights Reserved. Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Background

Taking cod liver oil as a source of vitamin D first became popular in 19th Century England. Fish oil has been studied for heart health since it was found that Greenland Inuit people may have a lower risk of heart disease despite eating a high-fat diet.

The main essential fatty acids in the human diet are omega-3 and omega-6 fatty acids. Foods that provide omega-3 fatty acids include fish oil and certain plant and nut oils, while omega-6 fatty acids can be found in palm, soybean, rapeseed, and sunflower oils. Omega-9 fatty acids, which are not considered essential, can be found in animal fat and olive oil.

Fish oil contains two omega-3 fatty acids called docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Some nuts, seeds, and vegetable oils contain alpha-linolenic acid (ALA), which may be converted to DHA and EPA in the body.

In the United States, percentages of DHA and EPA have been found to be lower compared to other nations with lower heart disease rates, such as Japan. High levels of omega-6 fatty acids have been linked to an increased risk of some conditions such as heart disease and depression.

Omega-3 fatty acids are thought to provide a wide range of health benefits, including a lower risk of coronary heart disease and improvement in cholesterol. There have also been promising results from studies looking at omega-3 for cancer, depression, and attention-deficit hyperactivity disorder (ADHD). Due to these potential health benefits, fish oil, which is rich in omega-3 fatty acids, has become a popular supplement.

There is evidence that recommended amounts of DHA and EPA, taken as fish or fish oil supplements, may lower triglycerides and reduce the risk of heart attack, abnormal heartbeat, and stroke in people who have heart disorders. DHA and EPA may also benefit people who have hardening of the arteries or high blood pressure. Similar effects have been found for ALA, but more evidence is needed to support its potential benefits.

High doses may have harmful effects, such as increased bleeding risk, higher levels of low-density lipoprotein (LDL, or "bad") cholesterol, blood sugar control problems, and a "fishy" odor. In some at-risk populations, such as people who have had a heart transplant, omega-3 fatty acids may affect the heart rate. Omega-3 fatty acids should be used only under medical care in people who have heart disease. Some fish such as swordfish, king mackerel, tilefish, and albacore tuna may carry a higher risk of mercury poisoning, though fish oil has not been found to carry a significant risk.

Lovaza® is a prescription drug that is approved by the U.S. Food and Drug Administration (FDA) for use in reducing very high triglycerides. It was first approved in November 2004 under the name Omacor® through Reliant Pharmaceuticals. Due to prescriptions misfilled with the drug Amicar®, the name was changed in July 2007 to Lovaza®.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

The average American consumes about 1.6 grams of omega-3 fatty acids daily. About 1.4 grams of this comes from ALA, while 0.1-0.2 grams from EPA and DHA. In Western diets, people eat about 10 times more omega-6 fatty acids than omega-3 fatty acids. These large amounts of omega-6 fatty acids come from vegetable oils such as corn oil, sesame oil, sunflower oil, and walnut oil. Because omega-6 and omega-3 fatty acids compete in the body, benefits may be reached either by decreasing omega-6 intake or increasing omega-3 intake.

The American Heart Association recommends that healthy adults eat fish at least twice weekly. Fatty fish such as catfish, halibut, salmon, striped sea bass, and albacore tuna are particularly recommended. Plant-based sources of ALA such as tofu, walnuts, and canola oil are also recommended. The World Health Organization recommends a daily EPA and DHA intake of 0.3-0.5 grams and a daily ALA intake of 0.8-1.1 grams.

To treat aggression, 1.5-1.8 grams of fish oil containing DHA plus EPA or fish oil containing 1.5 grams of DHA and 0.2 grams of EPA has been taken by mouth for 2-3 months.

To treat allergies in the infant, 1.6 grams of EPA and 1.1 grams of DHA (Bio Marin®, Pharma Nord, Vejle, Denmark) have been taken by mouth in mothers from the 25th week of pregnancy through 3-4 months of breastfeeding. Other studied doses include 3.7 grams of omega-3 fatty acids daily beginning at the 20th week of pregnancy until birth; 1.5 grams of omega-3 fatty acids daily during the first four months of breastfeeding; 0.5 grams of DHA plus 0.15 grams of EPA daily beginning at the 22nd week of pregnancy until birth; 2.7 grams of marine omega-3 fatty acids containing two milligrams per milliliter of tocopherol from the 30th week of pregnancy until birth; and 1.6 grams of EPA, 1.1 grams of DHA, and 23 milligrams of alpha-tocopherol taken by mouth daily from the 25th week of pregnancy through the end of breastfeeding.

To treat anxiety, three grams of omega-3 fatty acids have been taken by mouth daily in the form of five capsules containing 450 milligrams of EPA, 100 milligrams of DHA, and 50 milligrams of other triglyceride omega-3 fatty acids, for three months.

To treat stiff arteries, doses of one-gram capsules containing EPA plus DHA or 360-1800 milligrams of DHA plus 120-1,800 milligrams of EPA have been taken by mouth daily for 6-12 weeks. A dose of 1,800 milligrams of EPA has been taken by mouth daily for 6-12 weeks.

To treat asthma, fish oil capsules containing 2.7-3.2 grams of EPA and 1.8-2.2 grams of DHA or 0.2-1.0 gram of EPA plus DHA, 20 milliliters of fish oil, or 10-20 grams of perilla seed oil (containing ALA) have been taken by mouth daily for up to 12 months. A dose of one gram of EPA plus DHA (Liparmonyl®) has been taken by mouth daily for one year.

To improve athletic performance, eight capsules (each containing one gram of fish oil) has been taken by mouth daily for eight weeks. Fish oil capsules containing 3.2 grams of EPA plus 2.2 grams of DHA have been taken by mouth daily for three weeks.

To treat bipolar disorder, seven capsules have been taken by mouth twice daily (for a daily total of 6.2 grams of EPA and 3.4 grams of DHA) for four months along with conventional therapy. Flaxseed oil capsules containing 6.6 grams of ALA have been taken by mouth daily for 12-16 weeks. A dose of 360-6,200 milligrams of EPA plus 1,560-3,400 milligrams of DHA has been taken by mouth daily for 4-44 weeks. Seven capsules of menhaden fish body oil have been taken by mouth twice daily for four months. Fish body oil containing 6.2 grams of EPA plus 3.4 grams of DHA has been taken by mouth.

To treat weight loss in people with illness, 30 milliliters of fish oil has been taken by mouth daily, providing 4.9 grams of EPA and 3.2 grams of DHA for four weeks. A dose of 2-2.2 grams of EPA plus 0.96-1 gram of DHA have been taken by mouth daily for 3-7 weeks. A dose of 2-16 grams of fish oil has been taken by mouth daily for three months.

To treat cancer, 2.02-2.2 grams of EPA plus 0.92-1.0 grams of DHA (Prosure®, Abbott Laboratories) have been taken by mouth daily for five weeks to 60 days. A dose of 1.8 grams of EPA has been taken by mouth daily for 21 days before a bone marrow transplant and continued for 180 days afterwards. Eighteen capsules of fish oil containing 3.1-3.2 grams of EPA plus 2.0-2.2 grams of DHA have been taken by mouth daily for 14-40 days. Capsules containing two grams of fish oil have been taken by mouth daily for six weeks. Two cans of a fish oil-enriched supplement containing 1.09 grams of EPA have been taken by mouth daily for three weeks.

To prevent cancer, 4.1 grams of EPA and 3.6 grams of DHA have been taken by mouth daily for 12 weeks.

To treat abnormal heart rhythms, two grams of fish oil have been taken by mouth daily for 14-379 days. Four capsules containing two grams of fish oil composed of 0.464 grams of EPA, 0.335 grams of DHA, and 0.162 grams of other n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) have been taken by mouth daily for 12 months. A dose of 1.8 grams of fish oil containing 42% EPA plus 30% DHA has been taken by mouth daily for two years. Four one-gram capsules containing 2.6 grams of EPA plus DHA have been taken by mouth for 12 months. Two, four, or six capsules of fish oil, with 260 milligrams of DHA, and 60 milligrams of EPA per one-gram capsule, have been taken by mouth for 12 weeks. A dose of six grams of DHA-rich fish oil has been taken by mouth daily for 12 weeks; DHA-rich fish oil providing 0.36 grams of EPA and 1.56 grams of DHA daily has been taken by mouth daily in the form of Hi-DHA® from Nu-Mega Ingredients Pty. Ltd. Doses of 0.85-1.24 grams of EPA plus 1.0-1.76 grams of DHA have been taken by mouth daily beginning immediately after surgery and continuing until hospital discharge. A dose of 301.5 milligrams of ALA has been taken by mouth daily beginning four weeks before surgery and continuing for one year. Doses of 1-4 grams of omega-3 have been taken by mouth daily beginning up to one week before various heart surgeries and continuing for up to six months after electrical cardioversion, two weeks after coronary artery bypass grafting (CABG), or until discharge after open-heart surgery. Doses of 4-8 grams of PUFAs have been taken daily for 24 weeks. Doses of 850-882 milligrams of EPA plus DHA in a 1:2 ratio have been taken by mouth daily for five days prior to surgery and continuing until discharge from the hospital. A dose of two milligrams to two grams of omega-3 PUFAs containing 85-88% EPA plus DHA has been taken by mouth beginning five days before coronary artery bypass grafting and continuing until hospital discharge. A dose of two grams of omega-3 fatty acids (850-882 milligrams of EPA plus DHA in a 1.2:1 ratio) has been taken by mouth daily for five days following coronary artery bypass graft surgery. A dose of four grams of omega-3 fatty acids has been taken by mouth daily before surgery, followed by two grams daily after. A dose of 1,240 milligrams of EPA plus 1,000 milligrams of DHA has been taken by mouth beginning 5-7 days before open heart surgery and continuing until hospital discharge or two weeks after surgery. A dose of two grams of omega-3 fatty acids containing 85-88% EPA plus DHA has been taken by mouth daily for five days prior to surgery. A dose of eight grams omega-3 fatty acids containing 465 milligrams of EPA plus 375 milligrams of DHA has been taken by mouth daily for seven days, followed by four grams daily for 20 weeks. A dose of one gram of omega-3 fatty acids has been taken by mouth before direct current cardioversion. A dose of three grams of omega-3 fatty acids has been taken by mouth daily until electrical cardioversion (ECV), followed by two grams daily for six months. A dose of 301.5 milligrams of ALA has been taken by mouth daily for four weeks before and for one year after cardioversion. An infusion of 100 milligrams of fatty acids per kilogram containing a 0.9:1 ratio of EPA to DHA has been given intravenously beginning 12 hours before surgery and continuing until transfer from the intensive care unit.

To reduce the risk of heart disease, six capsules providing one gram of fish oil, containing 160 milligrams of EPA plus 100 milligrams of DHA, have been taken by mouth daily in divided doses for six months (two grams with each meal). Two capsules of Omacor® (now called Lovaza®; 460 milligrams of EPA and 380 milligrams of DHA) have been taken by mouth twice daily for 12 weeks. A dose of 2,080 milligrams of omega-3 fatty acids has been taken by mouth in four capsules, each containing 310 milligrams of EPA plus 210 milligrams of DHA, for 10 weeks. A dose of four grams (42% EPA and 25% DHA) has been taken by mouth daily for 12 weeks. A dose of two grams omega-3 fatty acids has been taken by mouth daily for 10 weeks. A dose of 250 milligrams of long-chain omega-3 fatty acids has been taken by mouth daily. Doses of 12 grams of fish oil (providing 4.0 grams of omega-3 fatty acids and 8-13 grams or 35 grams of ALA), one-gram capsules containing 0.5 grams of EPA plus DHA daily, and 0.45-4.5 grams of EPA plus DHA have been taken by mouth daily for periods ranging from 14 to 360 days. Doses of 0.2-6 grams of omega-3 fatty acids have been taken by mouth daily for 6-52 weeks. Flaxseed oil containing three grams of ALA has been taken by mouth daily for 26 weeks. Three flaxseed oil capsules or 25 grams of fat spread enriched with flaxseed oil containing 0.8-1.7 grams of EPA plus DHA or 4.5-9.5 grams of ALA have been taken by mouth daily for six months. Flax oil or fish oil containing 1.2-3.6 grams of ALA has been taken by mouth daily for 12 weeks. A dose of 4.5 grams of EPA plus DHA has been taken by mouth daily for five weeks. Doses of 2-6 grams of fish oil containing 26% DHA plus six percent EPA have been taken by mouth daily for 12 weeks. Flaxseed oil containing one gram of ALA, hempseed oil containing 0.3 grams of ALA, or fish oil containing 0.6 grams of EPA plus DHA has been taken by mouth daily for 12 weeks. Eight capsules containing a total of 9.6 grams of fish oil providing 1.728 grams of EPA plus 1.152 grams of DHA have been taken by mouth daily for 12 weeks. Six capsules containing six grams of fish oil providing three grams of n-3 LC-PUFAs have been taken by mouth daily for eight weeks.

To treat chronic obstructive pulmonary disease (COPD), an omega-3 PUFA-rich diet containing 0.6 grams of omega-3 PUFAs and 0.4 grams of omega-6 PUFAs has been used for 24 months.

To improve brain function, 0.25-0.68 grams of DHA plus 0.323-1.48 grams of EPA has been taken by mouth daily for 3-6 weeks.

To treat coronary heart disease, 10 grams of fish oil has been taken by mouth for 12 weeks. Doses of 3.4-4 grams of fish oil concentrate have been taken by mouth daily for nine months after bypass surgery. Doses of 6-7 grams of omega-3 fatty acids have been taken by mouth daily for six months. Doses of 0.23-5.4 grams of EPA and 0.15-3.6 grams of DHA have been taken by mouth for up to 6.2 years. Doses of 0.6-10 grams of omega-3 fatty acids have been taken by mouth daily for up to nine years. A dose of 0.5 grams of fish oil (MaxEPA®) has been taken by mouth daily for 24 months. For improved exercise tolerance, nine fish oil capsules containing 3.15 grams of omega-3 fatty acids have been taken by mouth for four months. A dose of 10 grams of fish oil has been taken by mouth for 12 weeks. EPA-rich fish oil (MaxEPA®, 2.8 grams of EPA) has been taken by mouth daily for three months. Doses of 0.85-6 grams of fish oil have been taken by mouth daily for up to 3.5 years, with the fish oil containing 1.08-2.24 grams of EPA plus 0.72-1.12 grams of DHA.

To treat Crohn's disease, doses of 1.2-3.3 grams of EPA and 0.6-1.8 grams of DHA have been taken by mouth daily for one year in the form of capsules.

To treat toxicity caused by cyclosporine, 3-6 grams of omega-3 fatty acids have been taken by mouth for up to six months. Doses of 9-18 grams of EPA have been taken by mouth.

To treat dementia, 700-1,940 milligrams of EPA plus DHA has been taken by mouth daily for 6-24 months. Margarine containing 400 milligrams of EPA and DHA or 400 milligrams of EPA and DHA plus two grams of ALA has been taken by mouth daily for 40 months. A dose of 4.3 grams of DHA has been taken by mouth daily for 12 months.

To treat depression, one gram of E-EPA (derived from 96% pure fish oil) has been taken by mouth two times daily for four weeks. One 1,000-milligram capsule (400 grams of EPA plus 200 milligrams of DHA) or two 500-milligram capsules (if unable to swallow the larger capsule; 190 milligrams of EPA plus 90 milligrams of DHA) have been taken by mouth daily for 16 weeks. A dose of 1.05 grams of ethylester-EPA plus 0.15 grams of ethyl-DHA has been taken by mouth daily in three divided doses for eight weeks. Four capsules (each containing 180 milligrams of EPA and 120 milligrams of DHA) have been taken by mouth daily for 12 weeks. Doses of 0.5-6 grams of omega-3 fatty acids have been taken by mouth daily for 6-8 weeks, from the third trimester until up to six months after giving birth, or for eight weeks beginning at 16-32 weeks of pregnancy. A dose of 1.1 grams of EPA plus 0.8 grams of DHA has been taken by mouth daily beginning at 12 weeks of pregnancy and continuing until six months after birth. Doses of 400-6,200 milligrams of EPA plus 150-3,400 milligrams of DHA have been taken by mouth for 4-24 weeks. Doses of 100-2,200 milligrams of EPA plus 800-1,200 milligrams of DHA have been taken by mouth daily for eight weeks or beginning at less than 21 weeks of pregnancy and continuing until birth. A dose of 4.4 grams of EPA plus 2.2 grams of DHA have been taken by mouth twice daily for eight weeks.

To treat diabetes, 0.6-4.6 grams of fish oil have been taken by mouth daily for four weeks to one year. Doses of 2-4 grams of omega-3 fatty acids have been taken by mouth daily. The following doses have been taken by mouth: 10 grams of fish oil concentrate composed of 30% omega-3 fatty acids daily for three weeks, 3.6 grams of fish oil containing n-3 LC-PUFAs daily for three months, six grams of fish oil daily, 3.6 grams of n-3 LC-PUFAs daily for three months, or 3.4 grams of ALA daily for 10 weeks. A dose of two grams omega-3 fatty acids has been taken daily for 10 weeks. A dose of one gram of omega-3 ethyl esters has been taken by mouth 2-3 times daily for 2-4 months.

To treat painful menstrual cramps, 2.5 grams of fish oil has been taken by mouth daily for 3-4 months.

To treat eczema, six grams of concentrated omega-3 fatty acids has been taken by mouth daily for four months during winter. A dose of 10 grams of fish oil has been taken by mouth for 12 weeks. The following doses have been taken by mouth: 12 capsules of fish oil daily (providing 2.0 grams of EPA plus 1.3 grams of DHA daily) or six one-gram capsules (containing 51% EPA, 32% DHA, and 3.6 international units per gram of DL-alpha-tocopherol) for 12-16 weeks. Doses of 1,800-3,060 milligrams EPA plus 1,200-1,920 milligrams of DHA has been taken by mouth. A dose of 1.6 grams of EPA plus 1.1 grams of DHA has been taken by mouth daily beginning at 25 weeks of pregnancy through 3-4 months of breastfeeding.

To improve exercise performance, 1,000 milligrams of fish oil, containing 180 milligrams of EPA plus 120 milligrams of DHA, has been taken by mouth during and after exercise for 12 weeks. Six capsules of one gram of fish oil (260 milligrams of DHA plus 60 milligrams of EPA per capsule) have been taken by mouth for five weeks.

To treat high blood pressure, 2-4 grams of omega-3 fatty acids has been used daily for up to one year.

To treat high triglycerides, doses of up to two grams of omega-3 fatty acids from EPA and DHA have been taken by mouth daily. Doses of 2-4 grams of omega-3 fatty acids taken by mouth daily have been studied. Doses of 0.3-6 grams of EPA, 0.7-3.72 grams of DHA, and two grams of ALA have been taken by mouth daily for at least six months. Doses of 0.045-15 grams of fish oil have been taken by mouth daily for six weeks to 3.5 years. Doses of 3-6.3 grams of ALA have been taken by mouth daily for 26 weeks to two years. Doses of 2-3 grams of MaxEPA® (180 milligrams of EPA plus 120 milligrams of DHA per capsule) have been taken by mouth three times daily for 4-6 weeks. A dose of five grams of Omega Rx, containing 400 milligrams of EPA plus 200 milligrams of DHA in each capsule, as well as 100 milligrams of vitamin E, has been taken by mouth for 13 weeks. Fish oil containing 180-1,750 milligrams of EPA plus 120-1,150 milligrams of DHA has been taken by mouth 1-3 times daily for 8-24 weeks. A dose of 300 milligrams of omega-3 fatty acids has been taken by mouth daily for four weeks. Doses up to 10 milligrams of EPA and DHA daily have been studied. A dose of two grams of Omacor® has been taken twice daily for 12-24 weeks. A dose of three grams of DHA (7.5 grams of DHA oil) has been taken by mouth daily for 90 days. A dose of 1.8 grams of tuna oil has been taken by mouth daily. Doses of four grams of omega-3 ethyl esters, three grams of salmon oil, six grams of fish oil, or 12.5 grams of omega-3 fatty acid liquid formulation (Omacor®, Pronova BioPharma, Norway, AS) have been taken by mouth daily for 4-16 weeks. The following doses have been taken by mouth: eight grams of marine-lipid concentrate daily for eight weeks; six grams of fish oil daily; 3.4 grams of ALA daily for 10 weeks; 0.8-1.7 grams of EPA plus DHA or 4.5-9.5 grams of ALA daily for six months; fish oil containing 180 milligrams of EPA plus 120 milligrams of DHA daily for three months; 15 milliliters of flaxseed oil containing 8.1 grams of ALA daily for 12 weeks; three grams of n-3 LC-PUFAs daily for 15 weeks; and two grams of fish oil daily for four weeks.

To treat IgA nephropathy (kidney disease in which there is a buildup of IgA antibodies), doses of 4-8 grams of omega-3 fatty acids containing 1.88-3.76 grams of EPA plus 1.47-2.94 grams of DHA have been taken by mouth daily for two years. Fish oil containing 0.85 grams of EPA plus 0.58 grams of DHA have been taken by mouth daily for four years. Doses of 4-12 grams of fish oil have been taken by mouth daily for 36 weeks to two years. Omega-3 fatty acids ranging from 1.4-5.1 grams have been taken by mouth daily for 6-48 months. Doses of 4-12 grams have been taken by mouth daily. A dose of 15 capsules of an unknown concentration taken by mouth daily for 2-12 months has been studied.

To improve appetite in people who have dementia, four one-gram capsules (1.7 grams of DHA and 0.6 grams of EPA) have been taken by mouth daily for 12 months.

To promote infant development, the following doses have been taken by mouth by mothers: 4-4.5 grams of fish oil containing 790-920 milligrams of DHA plus 620-1,280 milligrams of EPA daily beginning at 30 weeks of pregnancy and continuing until birth, or beginning at birth and continuing until the fourth month of breastfeeding; 10 milliliters of cod liver oil containing 1,183 milligrams of DHA plus 803 milligrams of EPA daily beginning at 18 weeks of pregnancy and continuing until the third month of breastfeeding; 1.5 grams of omega-3 fatty acids daily during the first four months of breastfeeding; and 10 milliliters of cod liver oil daily beginning at 18 weeks of pregnancy until three months after birth.

To promote eye and brain development in infants, 4.5 grams of fish oil have been taken by mouth daily by mothers during the first four months of breastfeeding. Mothers have taken fish oil capsules (containing DHA 200-2,200 milligrams and EPA 33-1,800 milligrams) by mouth daily beginning at 15-25 weeks of pregnancy until birth. Mothers have taken fish oil containing 1.5 grams of omega-3 fatty acids as capsules or cod liver oil containing 1.183 grams of DHA, 0.803 grams of EPA, and vitamins A, D, and E by mouth for 18 weeks. Fish oil containing 2.2 grams of DHA plus 1.1 grams of EPA has been taken by mouth daily by mothers beginning at 20 weeks of pregnancy to birth.

To treat inflammatory bowel disease, 2.4-5.6 grams of omega-3 fatty acids has been taken by mouth in one or two divided doses daily for up to two years. Omega-3 fatty acid capsules containing 1.2-2.2 grams of EPA and 0.6-0.9 grams of DHA have been taken by mouth daily for at least two months. The following doses have been taken by mouth: 5-6 grams of fish oil, 5.1 grams of fish oil capsules, or 20 milliliters of fish oil daily for 6-24 months (containing 3.2 grams of EPA plus 2.2 grams DHA), as well as doses of 6-15 grams daily or 20 milliliters daily of fish oil for 2-24 months.

To improve sensitivity to insulin, 0.138-4 grams of omega-3 fatty acids has been taken by mouth daily for eight weeks to six months.

To treat liver disease, 0.83-13.7 grams of omega-3 fatty acids has been taken by mouth daily for eight weeks to 12 months.

To treat lupus erythematosus (a chronic disease causing inflammation), doses of 15-20 grams of MaxEPA® (EPA) have been taken by mouth daily for 34 weeks. Doses of 20-440 grams have been taken by mouth daily for 12 weeks to 12 months.

To treat symptoms of menopause, 500 milligrams of E-EPA omega-3 fatty acid have been taken by mouth three times daily for eight weeks.

To treat migraine, three grams of omega-3 PUFAs have been taken by mouth twice daily for four months.

To treat muscle soreness, 324 milligrams of EPA plus 216 milligrams of DHA have been taken by mouth daily as Viva omega-3™ for 30 days before and two days following exercise.

To treat neck and shoulder pain, 1,200 milligrams of fish oil have been taken by mouth daily for one month.

To promote weight loss, six grams of tuna fish oil (approximately 1.9 grams of omega-3 fatty acids, containing 260 milligrams of DHA and 60 milligrams of EPA) has been taken by mouth for 12 weeks along with regular exercise. Five capsules of omega-3 PUFAs, with each capsule containing 1,000 milligrams of EPA plus 200 milligrams of DHA, have been taken by mouth daily for six months. The following doses have been taken by mouth: six fish oil capsules (0-3 grams of omega-3 fatty acids) daily for eight weeks, three grams of fish oil capsules containing 1.08 grams of EPA plus 0.72 grams of DHA daily for two months, six grams of tuna fish oil containing 260 milligrams of DHA plus 60 milligrams of EPA daily for 12 weeks, and five capsules containing one gram of fish oil (1.3 grams of EPA plus 2.9 grams of DHA) daily for 24 weeks.

To treat peripheral vascular disease (blocked blood flow to the limbs), a dose of 15 grams of fish oil has been taken by mouth daily for four weeks. Doses of 2-4 grams of omega-3 PUFAs have been taken by mouth daily.

To treat personality disorder, 2.1 grams of EPA plus 0.9 grams of DHA has been taken by mouth daily for 12 weeks.

To treat skin rash caused by the sun, five capsules each containing one gram of fish oil composed of 18% EPA plus 12% DHA have been taken by mouth daily for three months.

To treat high blood pressure associated with pregnancy, fish oil capsules (Pikasol®) containing 0.9-2.1 grams of DHA plus 1.3-2.9 grams of EPA have been taken by mouth daily, beginning at 20-33 weeks of pregnancy. Fish oil capsules containing 1.8 grams of EPA plus 1.2 grams of DHA have been taken by mouth daily. A dose of three grams of EPA plus some DHA has been taken by mouth daily for 27 weeks. A dose of 1.62 grams of EPA plus 1.08 grams of DHA has been taken by mouth daily for 14 weeks.

For pregnancy and labor, doses of 0.1-2.8 grams of EPA and DHA have been taken by mouth daily from week 17-27 of pregnancy until birth. A dose of 2.7 grams of omega-3 fatty acids (four one-gram capsules of Pikasol® oil) have been taken by mouth at 30 weeks of pregnancy. A dose of 2.7 grams of omega-3 fatty acids has been taken by mouth from 18-30 weeks of pregnancy until birth. Fish oil capsules (Pikasol®) containing 0.9-2.1 grams of DHA plus 1.3-2.9 grams of EPA have been taken by mouth daily, beginning at 20-33 weeks of pregnancy. Omega-3 fatty acid-enriched capsules containing three grams of EPA plus some DHA have been taken by mouth daily for 27 weeks. A dose of 1.62 grams of EPA plus 1.08 grams of DHA has been taken by mouth daily for 14 weeks. Doses of 1.10-3 grams of EPA plus up to 2.20 grams of DHA have been taken by mouth daily for 14-27 weeks.

To treat premenstrual syndrome (PMS), fish oil containing 18% EPA plus 12% DHA has been taken by mouth twice daily for three months.

To prevent graft failure after heart bypass surgery, a dose of four grams of fish oil concentrate has been taken by mouth daily.

To prevent blood vessel narrowing after coronary angioplasty, 15 capsules daily of one gram of fish oil (2.7-4.1 grams of EPA and 1.8-2.8 grams of DHA) have been taken by mouth for three weeks before surgery and continued for six months after. Doses of 0.045-5.4 grams of fish oil have been taken by mouth daily for six weeks to two years. Before surgery, 10 capsules containing three grams of fish oil composed of 1.8 grams of EPA plus 1.2 grams of DHA have been taken daily for six months.

To treat psychosis, omega-3 fatty acids containing 0.84 grams of EPA plus 0.70 grams of DHA have been taken by mouth daily. A dose of 1.2 grams of omega-3 fatty acids has been taken by mouth daily for three months.

To treat Raynaud's phenomenon (blocked blood flow to the limbs), 12 fish oil capsules (3.96 grams of EPA with 2.64 grams of DHA) have been taken by mouth daily for 17 weeks.

To treat rheumatoid arthritis, doses containing 0.5-4.6 grams of EPA and 0.2-3.0 grams of DHA, or 54 milligrams of EPA per kilogram plus 36 milligrams of DHA per kilogram, have been used daily for up to 15 months. A dose of 30 milliliters of seal oil containing two grams of EPA, 2.2 grams of DHA, and 0.9 grams of DPA has been taken in three divided doses daily for six months. A liquid nutritional supplement containing 16 milligrams of ALA, 211 milligrams of DHA, 40 milligrams of DPA, and 1.4 grams of EPA has been taken by mouth daily for four months. A dose of one gram per 10 kilograms of body weight of menhaden oil containing 245.3 milligrams of EPA and DHA has been taken by mouth daily for eight months. A dose of two grams of Neptune krill oil has been taken by mouth daily for eight days before and two days during menstruation for three months. A dose of 30 grams of flaxseed oil containing 32% ALA has been taken by mouth daily for three months. The following doses have been taken by mouth: 240 milligrams of EPA from fish oil daily, 10 capsules daily, and 18 grams daily for 10 days to 12 months. Omega-3 fatty acids have been given intravenously at doses of 0.1-0.2 milligrams per kilogram daily for seven days as add-on therapy. Omega-3 fatty acids (0.2 grams of fish oil emulsion per kilogram) have been given intravenously daily for 14 consecutive days, followed by 0.05 grams of fish oil taken by mouth daily for 20 weeks.

To prevent further heart problems in people with a history of heart disorders, 200-400 grams of oily fish has been taken by mouth each week (equal to 500-800 milligrams of daily omega-3 fatty acids). Fish oil and omega-3 supplements (containing 0.85-1.8 grams [850-1,800 milligrams] of EPA + DHA) have been taken by mouth. The following doses have been taken by mouth: 0.5 grams of fish oil (MaxEPA®) daily for 24 months, 1.8 grams of EPA plus 1.2 grams of DHA daily for seven months, 1.5 grams of omega-3 daily for 24 months, 2-4 grams of omega-3 fatty acids for 3.5-4.6 years, 0.3-4.1 grams of EPA plus 0.6-2.8 grams of DHA daily for 6-42 months, 1-5.1 grams of omega-3 fatty acids daily for 6-12 months, 400 milligrams of EPA and DHA daily for 40.8 months, three grams of fish oil (MaxEPA®) containing 0.54 grams of EPA plus 0.36 grams of DHA daily for 108 months, 2-5 grams of ALA daily for 24-46 months, 0.6-10 grams of DHA plus EPA daily for one month to nine years, 0.35 grams of DHA plus 0.51 grams of EPA daily for two years, 2.6 grams of omega-3 fatty acids daily for one year, 3.3 grams of omega-3 fatty acids daily for three months followed by 1.7 grams daily for 21 months, 0.23-2.9 grams of EPA plus 0.15-1.9 grams of DHA daily for one to 6.2 years, 1.7-6 grams of omega-3 daily for three months to 2.3 years, 0.96-2.6 grams of omega-3 fatty acids daily for 1-2 years, 0.85 grams of omega-3 daily for 3.9 years, 0.5 grams of omega-3 fatty acids daily for one year, 0.4-0.6 grams of omega-3 fatty acids daily for 4.7 years, 1-3.4 grams of omega-3 fatty acids daily for 1-1.5 years, or 0.27-4.8 grams of EPA plus DHA and 1.8-6.3 grams of ALA daily for up to five years.

To treat sepsis (shock), 7.2 grams of fish oil containing 1.1 grams of 20:5 n-3 fatty acids and 0.7 grams of 22:6 n-3 fatty acids have been taken by mouth daily for 3-4 weeks.

To treat sickle cell disease, 0.25 grams of menhaden fish oil per kilogram has been taken by mouth daily for one year.

To aid recovery from surgery, the following doses have been studied: enteral nutrition (feeding through a tube in the nose) containing 2.8-4.0 grams of EPA plus 1.4-1.9 grams of DHA daily for seven days after surgery, and 2.3 grams of EPA plus 1.0 gram of DHA taken by mouth daily five days before surgery and continuing as enteral nutrition for 21 days after surgery. Nutrition with the addition of Lipoplus™ containing omega-3 fatty acids from fish oil has been given through a feeding tube immediately after surgery until five days after surgery. Omegaven® (Fresenius Kabi) has been given through a feeding tube at a dose of one milliliter per kilogram containing 10% omega-3 fatty acids from hospital admission until discharge from the intensive care unit. A formula containing 10-20% fish oil has been given through a feeding tube for five days after surgery (Lipoplus® 20%, B. Braun; SMOFlipid®, Fresenius Kabi; Lipoplus®; olive oil emulsion containing 16.6% fish oil).

For kidney transplants, 1.9-3.0 grams of EPA plus DHA have been taken by mouth daily beginning 1-3 days after surgery and continuing for one month to one year. Doses of 1.2-5.4 grams of EPA plus DHA have been taken by mouth daily beginning 16 weeks to at least one year following surgery and continuing for three months to 26 weeks. For heart transplants, 3.0-3.4 grams of EPA plus DHA have been taken by mouth daily starting four days to 12 years after surgery. For liver transplants, 3.6 grams of EPA plus DHA has been taken by mouth.

To treat critical illness, Lipoplus® 20%, containing 90% medium-chain and long-chain triglycerides and 10% omega-3 fatty acids, has been given through a feeding tube for 12 hours. Omegaven® (Fresenius Kabi) containing 10% omega-3 fatty acids has been given through a feeding tube for seven days.

To treat inflammation of the pancreas, 0.15-0.2 grams of fish oil per kilogram has been given through a feeding tube daily for five days (Omegaven®, Fresenius, Germany). A dose of 0.2 grams of fish oil emulsion per kilogram has been given intravenously daily for two weeks.

To treat psoriasis, daily infusions with an omega-3 lipid emulsion (200 milliliters daily of 4.2 grams of EPA and DHA) have been given. A dose of 100 milliliters of omega-3 fatty acid-based lipid infusion (2.1 grams of EPA and 21 grams of DHA) has been given daily for 10 days.

Children (younger than 18 years)

Omega-3 fatty acids are used in some infant formulas, although information on effective doses is still unclear. Fresh fish intake should be limited in young children due to the risk of harmful contaminants from the environment. Fish oil capsules should not be used in children except under a healthcare professional's supervision.

To treat asthma, 84 milligrams of EPA and 36 milligrams of DHA (the daily dosages of EPA and DHA were 17-26.7 and 7.3-11.5 milligrams per kilogram of body weight, respectively) have been taken by mouth. A dose of 300 milligrams of EPA plus DHA has been taken by mouth daily for six weeks. A dose of 0.72 grams of EPA plus 0.48 grams of DHA plus ALA or 300-500 milligrams of fish oil containing 0.8-26.8 milligrams per kilogram of EPA plus 3.6-11.5 milligrams of DHA have been taken by mouth daily for up to 12 months.

To treat attention-deficit hyperactivity disorder (ADHD), 120 milligrams of ALA has been taken by mouth for seven weeks. Doses of 80-1,000 milligrams of EPA plus 2.7-558 milligrams of DHA have been taken by mouth daily for up to 30 weeks.

To treat autism, 1.3-1.5 grams of omega-3 fatty acid has been taken by mouth daily for 6-12 weeks.

To treat bipolar depression, 380-2,200 milligrams of EPA and 180-1,200 milligrams of DHA have been taken by mouth daily for 4-16 weeks. A dose of 6,600 milligrams of ALA has been taken by mouth daily for 16 weeks.

To improve brain function or treat metabolic disorders, 500 milligrams of fish oil (Ameu®, Omega Pharma, Berlin Germany) providing 18% EPA and 12% DHA has been taken by mouth daily for three months. Fish oil with final doses of 15 milligrams of DHA per kilogram has been taken by mouth daily for three months.

To treat cystic fibrosis, four one-gram capsules of fish oil have been taken by mouth twice daily for six weeks. A dose of 50 milligrams per kilogram of EPA plus DHA has been taken by mouth daily for three months.

To treat depression, 380-2,200 milligrams of EPA and 180-1,200 milligrams of DHA have been taken by mouth daily for 4-16 weeks. A dose of 6,600 milligrams of ALA has been taken by mouth daily for 16 weeks.

To treat painful menstrual cramps in adolescent girls, fish oil (1,080 milligrams of EPA and 720 milligrams of DHA) and 1.5 milligrams of vitamin E have been taken by mouth daily for two months.

To treat eczema, 1,800-3,060 milligrams of EPA plus 1,200-1,920 milligrams of DHA have been taken by mouth.

To prevent illness in children ages 9-12, fish oil (200 milligrams of EPA plus one gram of DHA), given in ultrahigh-temperature-processed (UHT) chocolate milk, has been used for five days per week for six months.

To promote infant development and motor skill development, 20 milligrams of liquid DHA has been taken by mouth daily for the first year of life.

To improve school attendance in children ages 9-12, six capsules (0.65 grams of DHA and 0.10 grams of EPA each) have been taken by mouth daily for three months.

To treat sepsis (shock), 100 milligrams of DHA (Neuromins for Kids, Martek Biosciences, Columbia, MD) has been given through stomach tube daily for 14 days.

Evidence

These uses have been tested in humans or animals.  Safety and effectiveness have not always been proven.  Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Key to grades

A
Strong scientific evidence for this use
B
Good scientific evidence for this use
C
Unclear scientific evidence for this use
D
Fair scientific evidence against this use (it may not work)
F
Strong scientific evidence against this use (it likely does not work)

Grading rationale

Evidence gradeCondition to which grade level applies
A

Coronary heart disease

Evidence suggests that people who have low levels of EPA and DHA may have a higher risk of coronary heart disease and heart failure. Clinical trials suggest that omega-3 fatty acids may have benefits in terms of reducing total and heart disease mortality (death). It is believed that omega-3 fatty acids may help lower triglycerides and inflammation. Daily intake has been linked to a reduced risk of sudden heart failure.
A

High blood pressure

Many studies report that omega-3 fatty acids may help reduce blood pressure. However, effects have generally been small, and other trials reported no benefit. Effects may be greater in people who have higher blood pressure and may depend on the dose. DHA may have greater benefits than EPA.
A

Hyperlipidemia (triglyceride lowering)

There is strong scientific evidence that omega-3 fatty acids from fish or fish oil supplements can significantly reduce triglyceride levels. Higher doses have been found to have greater effects, and a dose of four grams daily may lower triglyceride levels by up to 40%. Effects may be increased when taken with statin drugs such as simvastatin and atorvastatin.It is unclear how fish oil therapy compares to other agents used to lower triglycerides. Some studies suggest that fish oil may increase LDL levels.
A

Rheumatoid arthritis

Many studies report improvements in morning stiffness and joint tenderness with regular intake of fish oil supplements for up to three months. Benefits may increase with use of anti-inflammatory medications such as ibuprofen or aspirin. Benefits have also been seen with fish oil given through an intravenous tube. Fish oil has been found to have effects on the immune system and on fats in the blood in people with rheumatoid arthritis. However, effects beyond three months of treatment are unclear. More research is needed before a firm conclusion may be made.
A

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

Fish oil has been studied for use in protecting people who have had past heart problems from new ones, such as heart attack or sudden death.Many studies report that regularly eating oily fish or taking fish oil supplements may help reduce the risk of nonfatal and fatal heart attack, sudden death, and mortality in people with a history of heart attack. There is evidence that an increased intake of fish or omega-3 may be linked to a lower risk of heart failure. These therapies may add to the effects of other treatments, and benefits have been reported after three months of use.
C

Abnormal heart rhythms

There is promising evidence that omega-3 fatty acids may reduce the risk of abnormal heart rhythms. This effect is believed to contribute to the reduced number of heart attacks in people who regularly consume fish oil or EPA and DHA. However, not all studies have found positive results, as some reported that fish oil may be linked to abnormal heart rate in older people and people with a history of some heart problems. More studies are needed in this area before a firm conclusion may be made.
C

Acute respiratory distress syndrome (low oxygen in blood)

Early evidence suggests that taking fish oil may benefit adults who have acute respiratory distress syndrome. More research is needed to confirm this finding.
C

Age-related macular degeneration (loss of vision)

There is evidence that a diet high in omega-3 may reduce the risk of age-related macular degeneration (AMD). A combination product called Photorop, which contains omega-3, has been studied for use in people with this eye disease. DHA has been found to benefit eye health in nonsmoking older women. However, evidence on the use of omega-3 alone is limited. More studies are needed in this area.
C

Aggression

Early research suggests that fish oil may reduce stress-related aggression and help regulate mood and impulse control. More research is needed before firm conclusions can be made.
C

AIDS/HIV

Studies looking at the use of fish oil combined with other nutritional supplements in people with HIV have found conflicting results. More information is needed on the potential benefits of fish oil alone in this population.
C

Allergies

Research suggests that eating fish at least once per week may reduce the risk of eczema, an allergic condition causing dry and itchy skin, in children. However, a significant link between mother's fish intake and child eczema was lacking. Evidence is mixed in terms of whether mother's consumption of omega-3 may have effects on allergies in the infant. More research is needed in this area.
C

Antisocial personality disorder

Limited research suggests that omega-3 may help reduce some symptoms of personality disorder. However, more research is needed before firm conclusions can be made.
C

Anxiety

Omega-3 has been found to reduce tension in people attending an abuse clinic. More studies are needed in this area.
C

Asthma

There is conflicting evidence on the use of omega-3 for asthma. More research is needed before conclusions can be made.
C

Athletic performance

Research is limited on the use of fish oil for the improvement of athletic performance. Omega-3 has been found to have benefits on lung function in wrestlers and may improve muscle soreness. However, more studies are needed in this area.
C

Attention-deficit hyperactivity disorder (ADHD)

Fish oil may help increase levels of EPA, DHA, and total omega-3 fatty acids in people who have attention-deficit hyperactivity disorder (ADHD), which has been linked to lower omega-3 levels. However, significant differences were found to be lacking between healthy people and those with mental health problems such as dementia, ADHD, and depression. A combination product containing both omega-6 and omega-3 has been found to benefit people with ADHD. An Indonesian study reported that DHA-rich fish oil improved school attendance. More research is needed to determine the effect of omega-3 on learning and behavioral problems in ADHD.
C

Autism

Fish oil has been shown to help improve levels of omega-3 in people who have autism. However, conclusions are lacking in terms of benefits of omega-3 for autism. More research is needed.
C

Bipolar disorder

There is limited evidence to support the use of fish oil for bipolar disorder. One study reported longer recovery periods with use of fish oil. However, other research has produced conflicting results. More studies are needed before firm conclusions can be made.
C

Cancer

Conflicting results have been found for the effects of omega-3 on quality of life and mortality in people with cancer. More research is needed in this area.
C

Cancer prevention

Several studies report that fish oil may reduce the risk of breast, colon, prostate, or other cancers. However, results have been conflicting. Further research is needed before the use of fish oil can be supported for this purpose.
C

Chest pain

Early studies report a possible link between fish oil intake and reduced chest pain. More research is needed before further conclusions can be made.
C

Clogged arteries

Early research suggests that regular intake of fish oil supplements may lower the risk of clogged arteries. The role of supplements in preventing and treating clogged arteries has also been studied. However, more evidence is needed before the use of omega-3 can be supported for this purpose.
C

Cognition

EPA and DHA were found to lack effect on brain function in older people and healthy children. Some benefit was seen in children with metabolic disorders. More research is needed to determine the effect of omega-3 fatty acids on cognition in healthy people.
C

Critical illness

Omega-3 fatty acids in combination with other nutrients may help reduce the risk of serious complications in acutely ill people. Some studies report that omega-3 may decrease inflammation and the length of hospital stay. However, other findings are mixed, and further research is needed to support the use of fish oil in people with critical illness.
C

Cystic fibrosis (disease of the lungs and digestive system)

Limited research reports some benefit of fish oil for use in cystic fibrosis. However, evidence is still inconclusive, and more research is needed.
C

Dementia

There is some evidence that regular fish and omega-3 fatty acid consumption may help reduce dementia risk. However, results are conflicting. One review reported that firm conclusions are lacking in terms of the potential benefits of omega-3 on Alzheimer's disease. Another study found that omega-3 may help improve weight and appetite in people with Alzheimer's. Other studies found that significant differences were lacking between healthy people and those with mental health problems such as dementia and depression. While some findings are promising, more research is needed in this area.
C

Depression

There is inconclusive evidence to support the use of fish oil in people who have depression, although some early results are promising. Low levels of DHA and omega-3 have been linked to predicted suicide, and lower EPA has been linked to depressive symptoms in older people. Dietary intakes of fish and omega-3 have been found to help reduce depressive symptoms in women. Some studies report that fish and fish oil may help reduce risk of psychiatric disorders (including depression), as well as depression in people with heart disorders or type 2 diabetes. Omega-3 may benefit women who have depression in after giving birth. EPA is thought to have greater benefit than DHA. More research is needed.
C

Dialysis

Early evidence reports that fish oil may lack significant benefit in people on dialysis. People undergoing dialysis have been found to consume less omega-3 in the diet, and the possible link between omega-3 and mortality in this population has been studied. More research is needed to understand the potential benefits of fish oil use in these people.
C

Dyslexia

Early studies have found that a combination treatment containing EPA may lack benefit in dyslexic children with reading and spelling problems. More research is needed in this area.
C

Eczema

There is evidence that taking fish oil in infancy may help prevent the development of eczema, an itchy skin condition. Studies suggest that fish consumption in infancy may be more important than the mother's fish intake during pregnancy. However, results are still inconclusive at this time, and more information is needed.
C

Energy

Studies suggest that athletes who take fish oil may reduce oxygen consumption during exercise. However, other research has found a lack of effect of fish oil on energy or metabolism in healthy people. Further research is needed.
C

Epilepsy

Omega-3 supplements may help improve brain energy and health in people who have epilepsy. More research is needed to determine whether omega-3 may be an effective treatment for people with this condition.
C

Fatigue

There is limited evidence supporting the use of fish oil and other essential fatty acids for treating chronic fatigue. More research is needed before conclusions can be made.
C

Heart disease (risk)

Omega-3 fatty acids may benefit some heart disease risk factors. However, conclusive evidence is lacking. Some studies have found benefit for risk factors such as triglyceride levels, but more research is needed to determine whether the actual heart disease risk is reduced.
C

High blood pressure associated with pregnancy

There is not enough evidence to support the use of fish oil for high blood pressure during pregnancy. Further research is needed in this area.
C

High cholesterol

As discussed earlier, there is strong scientific evidence that omega-3 fatty acids from fish or fish oil supplements help reduce triglyceride levels. Some studies report that fish oil may increase LDL cholesterol, possibly by increasing the size of LDL particles. More research is needed to determine potential benefits of omega-3 for lowering cholesterol.
C

Immune function

There is evidence that fish oil may help reduce inflammation. Although not well studied in humans, fish oil may also improve survival after infection, prolong survival after an organ transplant, and benefit autoimmune disease. More human research is needed in this area.
C

Infant development / neonatal care

One study found that taking DHA during the first year of life may reduce time to the first occurrence of sitting without support. However, effects on other measures such as crawling or standing and walking alone were lacking. The use of omega-3 fatty acids has also been studied for health issues during infancy. Findings on the effects of omega-3 for later body composition of the infant are mixed. More research is needed.
C

Infant eye / brain development

Early research suggests that DHA taken by pregnant and breastfeeding mothers may reduce the body mass index of infants. However, effects are lacking on length or head size of infants. The mother's fish oil intake during pregnancy has been found to lack effect on infant language development. The effect of DHA-enriched formulas has been studied for the safety, growth, and development of preterm and term infants. More research is needed in this area.
C

Inflammation

Omega-3 fatty acids have been found to lack significant effects on inflammation and outcome in people in intensive care. Further research is needed.
C

Inflammatory bowel disease

Many studies have looked at the possible benefit of omega-3 fatty acids in people who have inflammatory bowel diseases, such as ulcerative colitis and Crohn's disease, when used with standard therapy. Although some positive effects have been found, results are conflicting, and more evidence is needed.
C

Kidney disease (IgA nephropathy)

Results are conflicting on the use of fish oil to treat IgA nephropathy, a kidney disease in which there is a buildup of IgA antibodies. More research is needed before firm conclusions can be made.
C

Kidney disorders (nephrotic syndrome)

There is not enough reliable evidence to support the use of omega-3 for nephrotic syndrome, a condition in which kidney problems lead to high protein levels in urine. More research is needed in this area.
C

Kidney stones

The effect of fish oil on kidney stones has limited clinical evidence. More research is needed before a conclusion can be made.
C

Liver disease

Early research reports that fish oil may help reduce liver disease linked to tube feeding in children. EPA has been studied for liver health in people who have nonalcoholic liver disease. A combination of both omega-3 and omega-6 used in tube feeding lacked evidence of a large benefit on recovery after a liver transplant. Further research is needed.
C

Lung conditions

Omega-3 has been found to benefit people who have chronic obstructive pulmonary disorder (COPD), a lung condition that makes it difficult to breathe. Further research is needed in order to confirm these findings.
C

Lupus (chronic disease causing inflammation)

Reliable evidence is lacking to support the use of fish oil for people who have lupus. More research is needed before a conclusion can be made.
C

Menopause

Conclusions on the potential benefits of omega-3 for symptoms of menopause cannot be drawn at this time. Further research is needed.
C

Menstrual pain

It has been suggested that omega-3 fatty acids may help manage painful menstrual cramps. Early evidence suggests that fish oil may benefit women who have menstrual pain. However, more research is needed before a firm conclusion can be made.
C

Migraine

Omega-3 supplementation has been found to lack significant effect on migraines. More research is needed before a conclusion may be made.
C

Movement disorders

Omega-3 fatty acids have been studied for use in children with dyspraxia, a movement disorder, with some benefits having been seen. However, more research is needed in this area.
C

Multiple sclerosis

One study reported that a link between fatty acid levels and depression was lacking in people with multiple sclerosis. However, some omega-3 fatty acids were lower in those with the condition, compared to healthy controls. Early research has found a lack of benefit of omega-3 in the treatment of multiple sclerosis. More research is needed before a conclusion can be made.
C

Neck/shoulder pain

Early research suggests that omega-3 supplementation may help improve neck and shoulder pain. However, more well-designed trials are needed.
C

Nerve pain

Omega-3 fatty acids may benefit people who have nerve pain caused by various conditions, including fibromyalgia, carpal tunnel syndrome, and burn injury. More evidence is needed to support the use of omega-3 for this purpose.
C

Osteoarthritis

Significant effects of fish oil were lacking on pain and functioning in people with osteoarthritis. Larger clinical trials are needed before a conclusion may be made.
C

Osteoporosis

Some studies report a decreased risk of osteoporosis with fish intake and benefits of fish oil supplementation on bone health. Omega-3 intake has been linked to better bone density in older people, although there are some conflicting results. More well-designed clinical trials are needed in this area.
C

Overall well being

One study found that children who drank chocolate milk supplemented with fish oil had fewer illnesses. However, more research is needed in this area.
C

Pancreatitis (inflammation of the pancreas)

Fish oil given with nutrition through tube feeding has been found to reduce the inflammatory response in people with pancreatitis. More research is needed in this field.
C

Peripheral vascular disease (blocked arteries in the legs)

Some evidence suggests that fish oil may improve blood pressure in the legs of people who have peripheral vascular disease and improve the ability to walk long distances. However, more research is needed to better understand this effect.
C

Phenylketonuria (inability to break down the amino acid phenylalanine)

Low DHA levels are common among children with phenylketonuria (PKU) during the first year of life due to dietary restrictions. Early research suggests that supplementing with omega-3 during the first year of life may help improve fatty acids so that they are similar to those of healthy, breastfed infants. Effects of omega-3 fatty acids on brain function in children with PKU are still unclear. More clinical research is needed.
C

Pregnancy and labor

Early evidence suggests that fish oil may lack effect on the timing of spontaneous delivery. Fish intake in the third trimester has been linked to birthweight. Some studies report that intake of omega-3 fatty acids may reduce the risk of preterm (early) birth. However, there is some conflicting evidence. The effect of fish oil supplementation on labor and delivery is still uncertain at this time.
C

Premenstrual syndrome (PMS)

Early studies suggest that fish oil may help reduce emotional symptoms and menstrual cramps. More research is needed in this area.
C

Prevention of graft failure after heart bypass surgery

There is limited research on the use of fish oils in people undergoing coronary artery bypass grafting. Early studies suggest small benefits in reducing blood clot formation in vein grafts. One review found that using EPA before the operation may have benefit. More research is needed before a firm conclusion can be made.
C

Prevention of restenosis after coronary angioplasty (PTCA)

Several studies have looked at whether omega-3 fatty acid intake reduces restenosis, or blood vessel narrowing, after coronary angioplasty. Some research has reported small, significant benefits, while others have not found positive effects. The evidence in this area is still inconclusive at this time.
C

Primary cardiovascular disease prevention (alpha-linolenic acid [ALA])

Research has found a reduced risk of fatal or nonfatal heart attack in people who regularly eat foods high in ALA. However, other studies have found conflicting evidence. More research is needed before a conclusion may be made in this area.
C

Prostate disorders

There is limited evidence in support of the use of fish oil for prostate disorders. Clinical research suggests that EPA may lack significant effect. More research is needed to understand the effect of fish oil in people who have prostate disorders.
C

Psoriasis (autoimmune disease causing flaky, scaly skin)

Several studies looking at psoriasis and fish oil do not provide enough reliable evidence to form a clear conclusion. Further research is needed before conclusions can be made.
C

Psychosis (loss of contact with reality)

People who are at risk of psychosis may benefit from consuming omega-3 fatty acids. However, available information is based on limited research, some of which included people taking antipsychotic medications. More research is needed.
C

Quality of life

Omega-3 fatty acids do not appear to improve quality of life in elderly people. More research is needed.
C

Raynaud's disease (blocked blood flow to the limbs)

Early clinical evidence suggests that omega-3 fatty acids may benefit people who have Raynaud's disease. More research is needed to better understand and confirm this finding.
C

Schizophrenia

There is promising early evidence suggesting that EPA may benefit symptoms of schizophrenia. Clinical trials looking at omega-3 fatty acids that contain a mixture of EPA and DHA are limited, as most studies have looked at EPA alone. DHA levels may change in people who have schizophrenia. Further research is needed before a conclusion can be made.
C

Secondary cardiovascular disease prevention (alpha-linolenic acid [ALA])

Several studies have looked at the effects of ALA in people with a history of heart attack. Although some studies suggest benefits, others do not. More research is needed before a conclusion may be made in this area.
C

Shock

Early research found that omega-3 fatty acids may reduce mortality, antibiotic use, and length of hospital stay in people with sepsis, or shock. DHA was found to increase body fat and length in infants following sepsis. However, further research is needed in this area.
C

Sickle cell disease

Limited evidence suggests that fish oil may benefit people who have sickle cell disease. More research is needed to determine dosing, side effects, and benefits on other sickle cell symptoms.
C

Stroke prevention

Several large studies have looked at the effects of omega-3 fatty acid intake on stroke risk. Some studies suggest benefits, while others do not. Very large intakes of omega-3 fatty acids may actually increase the risk of stroke. It is unclear if there are benefits in people with or without a history of stroke, or if effects of fish oil are comparable to other treatments.
C

Sun protection

Treatment with fish oil may help reduce inflammation caused by the sun in people who have polymorphic light eruption, a condition in which sunlight causes skin rashes. Further research is needed.
C

Surgical recovery

A combination product containing omega-3 fatty acids has been shown to improve inflammation and immune responses before and after surgery. However, in early research, the effects of omega-3 fatty acids were mixed on reduced mortality (death), antibiotic use, and length of hospital stay after stomach surgery. More research is needed.
C

Tardive dyskinesia (uncontrolled, repetitive movements)

Evidence of a link between fatty acid levels, schizophrenia, and movement disorders is inconclusive. Further research is needed in this area.
C

Toxicity

Many studies have looked at the effects of fish oil supplements on toxicity in people who are given drugs that affect the immune system, such as cyclosporine (Neoral®). Most trials report improved kidney function. Although more recent studies report a lack of kidney benefits, the weight of scientific evidence supports the positive effects of fish oil.
C

Vasodilator (widens blood vessels)

In early research, omega-3 fatty acids increased forearm blood flow in people with chronic heart failure. Fish oil appeared to have more significant effects in younger men, compared to older men. More information is needed in this area.
C

Weight loss

Dietary fish has been found to increase the effects of a weight loss program in improving metabolism and cholesterol in obese people. One study reported that fish oil supplementation helped lower fat mass, but combined studies found a lack of effect on weight loss. Research has looked at the effect of omega-3 on weight gain, due to the calorie content of omega-3 fatty acids. When taken with fenofibrate for up to 16 weeks, there was a lack of weight gain. Further research is needed to understand the potential benefits of omega-3 for weight loss.
C

Wound healing

Although it has not been well studied in humans, some research suggests that applying fish oil to the skin may increase wound healing. Early human research reports that omega-3 fatty acids may lack this benefit. More well-designed studies are needed to determine the potential effects of omega-3 for this purpose in humans.
D

Appetite / weight loss in cancer patients

There is mixed evidence in support of fish oil use for improving appetite or preventing weight loss in people with cancer.
D

Diabetes

Available evidence suggests that significant long-term effects of fish oil in people with diabetes are lacking. The effects of fish oil on high triglycerides were similar in people with or without diabetes. Higher consumption of omega-3 fatty acids and fish did not appear to lower the risk of type 2 diabetes in some studies but did modestly increase its risk in others. Dietary intake of omega-3 fatty acids has been studied in children at genetic risk for type 1 diabetes.
D

Transplant rejection prevention

Many studies have looked at the effects of fish oil in people who received a heart or kidney transplant and were taking cyclosporine (Neoral®). The majority of trials reported improved kidney function and less high blood pressure, compared to people not taking fish oil. However, several recent studies reported no benefits to kidney function, and no changes have been found in rates of rejection or graft survival.

Uses based on tradition or theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Agoraphobia (fear of crowds), antioxidant, bacterial infections, blood clotting disorders, blood thinner, breast pain (mastalgia), breast cysts, breast tenderness, central nervous system disorders, chemotherapy side effects (from anthracycline, isotretinoin, methotrexate), common cold, deficiency (omega-3 fatty acid), dermatomyositis (muscle disease causing rash and inflammation), ear infection, fibromyalgia (long-term joint and muscle pain), gallstones, glaucoma, gout, gum disease, hearing loss (age-related), hepatorenal syndrome (liver disease causing kidney failure), hypoxia (lack of oxygen), ichthyosis (skin disorder), increasing lifespan, infertility, kidney disease (polycystic), kidney inflammation (nephritis), leprosy, malaria, male infertility, memory enhancement, mental retardation, metabolic disorders, muscle weakness, musculoskeletal problems, neurological disorders (Refsum's syndrome), night vision enhancement, panic disorder, Parkinson's disease, psychiatric disorders (childhood), retinal protection, Reye's syndrome (sudden brain damage and liver problems), Sjögren's syndrome (dry eyes and mouth), stomach disorders, substance abuse, suicide prevention, tennis elbow, vasculitis (blood vessel inflammation), vision enhancement.

Interactions

Interactions with Drugs

Omega-3 may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin®) or heparin, antiplatelet drugs such as clopidogrel (Plavix®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).

Omega-3 may affect blood sugar levels. Caution is advised when using medications that may also affect blood sugar. People taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.

Omega-3 may cause low blood pressure. Caution is advised in people taking drugs that lower blood pressure.

Omega-3 may also interact with agents that may affect the immune system, agents that may affect the nervous system, agents that may be toxic to the liver, agents that may treat abnormal heart rhythms, agents that may treat arthritis, agents that may treat asthma, agents that may treat gout, agents that may treat heart disorders, agents that may treat retrovirus infections (HIV), antiallergic agents, antiandrogens, anticancer agents, antidepressants (SSRIs), antiestrogens, anti-inflammatories, antipsychotics, aspirin, bone agents, cholesterol-lowering agents, cyclosporine, dexamethasone, eye agents, hormonal agents, paclitaxel, skin agents, and stomach agents.

Interactions with Herbs and Dietary Supplements

Omega-3 may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.

Omega-3 may affect blood sugar levels. Caution is advised when using herbs or supplements that may also affect blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.

Omega-3 may cause low blood pressure. Caution is advised in people taking herbs or supplements that lower blood pressure.

Omega-3 may also interact with antiallergic agents, antiandrogens, anticancer herbs and supplements, antidepressants (SSRIs), antiestrogens, anti-inflammatories, antioxidants, antipsychotics, bone agents, cholesterol-lowering herbs and supplements, conjugated linoleic acid, evening primrose oil, fat-soluble vitamins, folate, gamma-linolenic acid, glucosamine, herbs and supplements that may affect the immune system, herbs and supplements that may affect the nervous system, herbs and supplements that may be toxic to the liver, herbs and supplements that may treat abnormal heart rhythms, herbs and supplements that may treat arthritis, herbs and supplements that may treat asthma, herbs and supplements that may treat heart disorders, hormonal herbs and supplements, hormone replacement therapy, lycopene, medium-chain triglycerides, phosphatidylserine, phytosterols, policosanol, selenium, skin agents, stomach agents, and vitamin E.

Methodology

This information is based on a systematic review of scientific literature and was peer-reviewed and edited by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Monograph methodology

Related terms

Aceite de pescado (Spanish), ácido alfa-linolénico (Spanish), ácidos grasos omega-3 (Spanish), ALA, alpha-linolenic acid (ALA, C18:3 n-3), cod liver oil, coldwater fish, DHA, docosahexaenoic acid (DHA, C22:6 n-3), docosapentaenoic acid (DPA, 22:5 n-3), DPA, eicosapentaenoic acid (EPA, C20:5 n-3), EPA, fish body oil, fish extract, fish liver oil, fish oil, fish oil fatty acids, halibut oil, krill oil, Lipoplus®, Lipoplus® 20%, long-chain polyunsaturated fatty acids, Lovaza®, mackerel oil, marine oil, MaxEPA®, menhaden oil, n-3 fatty acids, n-3 polyunsaturated fatty acids, Omacor®, omega fatty acids, Omega Rx, omega-3 fatty acids, omega-3 oils, Omegaven®, polyunsaturated fatty acids (PUFAs), salmon oil, seal oil, shark liver oil, SMOFlipid®, w-3 fatty acids.

Note: This patient monograph is based on a search of omega-3 fatty acids in general, not the individual omega-3 fatty acids. Additional professional monographs are available on DHA, EPA, fish oil, and alpha-linolenic acid (ALA). Omega-3 fatty acids should not be confused with omega-6 fatty acids.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Avoid fish-derived omega-3 supplements if allergic or sensitive to fish, fish oil, or omega-3 fatty acid products derived from fish. Avoid plant-derived omega-3 supplements if allergic or sensitive to nuts, seeds, or plants from which they are derived.

Skin rash and allergic response have been reported.

Some studies suggest that fish exposure during infancy and childhood may help reduce the risk of allergy in childhood.

Side Effects and Warnings

Omega-3 is considered likely safe when taken as a supplement in recommended doses for up to 2-3.5 years, or when included in the diet (1-2 fish meals per week). The U.S. Food and Drug Administration (FDA) has ruled that the use of EPA and DHA, the primary omega-3 fatty acids found in fish, as dietary supplements is safe and lawful, as long as daily intakes do not exceed three grams per person daily from food and supplement sources.

Omega-3 is considered possibly safe when taken by mouth in amounts found in foods during pregnancy and breastfeeding. There is not enough information at this time regarding the safety of fish oils when used in amounts greater than those found in foods during pregnancy and breastfeeding. Up to 20 grams of fish may be well tolerated by most adults, although some experts warn that high doses may cause bleeding complications.

Omega-3 may increase the risk of bleeding, particularly at doses of three grams daily or greater. Caution is advised in people with bleeding disorders or those taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.

Omega-3 may affect blood sugar levels. Caution is advised in people with diabetes or hypoglycemia and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist, and medication adjustments may be necessary.

Omega-3 may cause low blood pressure. Caution is advised in people taking drugs or herbs and supplements that lower blood pressure.

Use cautiously in all people, as omega-3 may affect levels of cholesterol and may cause vitamin E deficiency.

Use cautiously in people who are at risk for hormone imbalance or those undergoing hormone replacement therapy.

Use cautiously in people who have abnormal heart rhythms, asthma, and inflammatory bowel disease, as worsened outcomes have been reported with omega-3 use.

Use cautiously in people with liver disease or those using agents that may be toxic to the liver. Changes in liver function tests have been reported with omega-3 use.

Use cautiously in people who are at risk for colon cancer. Fish oils may increase the risk of colon cancer.

Use cautiously in large amounts, as vitamin A and D toxicity may occur.

Use cautiously in children and in pregnant or breastfeeding women, due to the potential that fish meat may contain mercury.

Avoid fish-derived omega-3 supplements if allergic or sensitive to fish, fish oil, or omega-3 fatty acid products derived from fish. Avoid plant-derived omega-3 supplements if allergic or sensitive to nuts, seeds, or plants from which they are derived.

Omega-3 may also cause abnormal heart rhythm, abnormally high urination, acid reflux, anemia, anorexia, bad breath, bad taste in the mouth, bloating, bloody urine, blurred vision, burping, cancer, changes in energy and physical activity (in infants whose mothers received supplementation), changes in homocysteine levels, the common cold, constipation, diarrhea, dizziness, excess fat in the stool, fainting (in pregnant women at birth), a feeling of ants crawling on the skin, a feeling of burning or prickling, a feeling of lifelessness, fever, fishy hiccups, gas, headache, heart attack, hospitalization (chest pain, congestive heart failure, or nervous system problems), increased risk of stroke, indigestion, intolerance to capsule number or size, mania, memory problems, muscle pain or swelling, nausea, the need for surgery (coronary revascularization), nervous system toxicity, nosebleed, restlessness, sleep problems, sudden cardiac death, skin problems (irritation, itching, rashes), stomach pain, throat pain, tiredness, vomiting, and weight gain.

Pregnancy and Breastfeeding

High DHA intakes have been reported in healthy pregnant women in Spain, Germany, and Hungary, ranging from 119 to 155 milligrams.

Fertility research suggests that fertile men may have higher levels of omega-3 compared to infertile men.

There are concerns that some species of fish may contain contaminants that may be harmful to pregnant or breastfeeding women. Mercury tends to build up in fish meat more than in fish oil, and fish oil supplements appear to contain almost no mercury. As a result, safety concerns may apply to eating fish, but likely not to taking fish oil supplements.

The U.S. Environmental Protection Agency recommends that pregnant and breastfeeding women limit sport-caught fish intake to one six-ounce meal per week. For farm-raised, imported, or marine fish, the FDA recommends that pregnant and breastfeeding women avoid eating types with higher mercury levels (such as mackerel, shark, swordfish, or tilefish) and less than 12 ounces per week of other fish types. Women who might become pregnant are advised to eat up to seven ounces per week of fish with higher mercury levels or up to 14 ounces per week of fish types with lower mercury content (such as marlin, orange roughy, red snapper, or fresh tuna). Some experts recommend more than one weekly portion of oily sea fish, or a DHA supplement, for pregnant women.

Omega-3 fatty acid levels of mother and infant may be related. Taking fish oil during pregnancy may promote higher DHA concentration in the newborn. DHA supplementation of the mother may increase DHA in the mother's blood and breast milk.

It is still unclear whether omega-3 supplementation during pregnancy and breastfeeding may benefit infants. Although it has been suggested that omega-3 during pregnancy may increase the birthweight and length of the baby, high doses may not be advisable due to a potential bleeding risk. Some studies report that DHA supplementation of mothers may affect infants' body mass index, fat mass, and weight. DHA may be important in the growth and development of the infant brain and has been studied for potential benefits in preventing respiratory illnesses during the first year of life. However, more research is needed.

Omega-3 has been studied for its potential effects in reducing the risk of preterm birth.

Fish oil supplementation of the mother during breastfeeding may cause decreased physical activity level and increased energy, starch intake, and blood pressure in infant boys.

Selected references

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  2. Aranceta J and Perez-Rodrigo C. Recommended dietary reference intakes, nutritional goals and dietary guidelines for fat and fatty acids: a systematic review. Br.J.Nutr. 2012;107 Suppl 2:S8-22.
  3. Caspar-Bauguil S, Montastier E, Galinon F, et al. Anorexia nervosa patients display a deficit in membrane long chain poly-unsaturated fatty acids. Clin.Nutr. 2012;31(3):386-390.
  4. Dekker LH, Fijnvandraat K, Brabin BJ, et al. Micronutrients and sickle cell disease, effects on growth, infection and vaso-occlusive crisis: a systematic review. Pediatr.Blood Cancer 2012;59(2):211-215.
  5. Delgado-Lista J, Perez-Martinez P, Lopez-Miranda J, et al. Long chain omega-3 fatty acids and cardiovascular disease: a systematic review. Br.J.Nutr. 2012;107 Suppl 2:S201-S213.
  6. Gil-Campos M and Sanjurjo Crespo P. Omega 3 fatty acids and inborn errors of metabolism. Br.J.Nutr. 2012;107 Suppl 2:S129-S136.
  7. Khawaja O, Gaziano JM, and Djousse L. A meta-analysis of omega-3 fatty acids and incidence of atrial fibrillation. J.Am.Coll.Nutr. 2012;31(1):4-13.
  8. Klingler M and Koletzko B. Novel methodologies for assessing omega-3 fatty acid status - a systematic review. Br.J.Nutr. 2012;107 Suppl 2:S53-S63.
  9. Kwak SM, Myung SK, Lee YJ, et al. Efficacy of omega-3 fatty acid supplements (eicosapentaenoic acid and docosahexaenoic acid) in the secondary prevention of cardiovascular disease: a meta-analysis of randomized, double-blind, placebo-controlled trials. Arch.Intern.Med. 5-14-2012;172(9):686-694.
  10. Mahady SE and George J. Management of nonalcoholic steatohepatitis: an evidence-based approach. Clin.Liver Dis. 2012;16(3):631-645.
  11. Morris MC. Nutritional determinants of cognitive aging and dementia. Proc.Nutr.Soc. 2012;71(1):1-13.
  12. Ries A, Trottenberg P, Elsner F, et al. A systematic review on the role of fish oil for the treatment of cachexia in advanced cancer: an EPCRC cachexia guidelines project. Palliat.Med. 2012;26(4):294-304.
  13. Sarris J, Mischoulon D, and Schweitzer I. Omega-3 for bipolar disorder: meta-analyses of use in mania and bipolar depression. J.Clin.Psychiatry 2012;73(1):81-86.
  14. Wanden-Berghe C and Sanz-Valero J. Systematic reviews in nutrition: standardized methodology. Br.J.Nutr. 2012;107 Suppl 2:S3-S7.
  15. Wong CY, Yiu KH, Li SW, et al. Fish-oil supplement has neutral effects on vascular and metabolic function but improves renal function in patients with Type 2 diabetes mellitus. Diabet.Med. 2010;27(1):54-60.

This evidence-based monograph was prepared by The Natural Standard Research Collaboration

www.naturalstandard.com