The Benefits of Fish Oil
Fish oil is high in two
kinds of omega-3 fatty acids, EPA and DHA (eicosapentaenoic and
docosahexaenoic acids). EPA and DHA are polyunsaturated fats, the "good" fats, as opposed to the "bad" fats, which are saturated fats. The body can manufacture both EPA and DHA from another essential fatty acid, alpha-linolenic acid (ALA) -- found in flaxseed oil, canola oil, soy oil and walnut oil -- but only to a limited extent.
Omega-3 fatty acids are thought to:
- Reduce cardiovascular disease risk. The cardiovascular effects of Omega-3 fatty acids have been the most widely studied subject to date. Evidence from several studies has suggested that amounts of DHA and EPA in the form of fish or fish oil supplements lowers triglycerides, slows the buildup of atherosclerotic plaques ("hardening of the arteries"), lowers blood pressure slightly, as well as reduces the risk of death, heart attack, dangerous abnormal heart rhythms, and strokes in people with known heart disease.(13, 30)
- Lower blood pressure Multiple human trials report small reductions in blood pressure with intake of omega-3 fatty acid although it appears necessary to take high amounts of omega-3 fatty acids per day to obtain these health benefits, and high doses may increase the risk of bleeding. Therefore, a qualified healthcare provider should be consulted before starting treatment with fish oil supplements (30).
- Help rheumatoid arthritis Many studies report improvements in morning stiffness and joint tenderness with the regular intake of fish oil supplements for up to three months. Fish oil has been shown to increase the effects of anti-inflammatory medications, such as NSAIDs (such as ibuprofen). However, more research is needed before a strong favorable recommendation about RA can be made.(24, (26, 30)
- Improve depression, bipolar disorder, and schizophrenia. This is according to a limited number of double-blind trials and more research is needed to confirm these findings.(27, 30)
- Reduce dementia and slow cognitive decline Several recent studies have found neuroprotective benefits of omega-3 fatty acids with respect to mental decline. In one trial from Tufts in Boston, patients with higher plasma levels of DHA, had a 47% reduction in the risk of all-cause dementia and a 39% reduced risk of Alzheimer's. In a separate study by Columbia University researchers, a Mediterranean-style diet appeared to help fend off Alzheimer's. A Mediterranean diet is low in red meat and high in fruits, vegetables, and olive oil. And in another study, Swedish researchers found evidence that dietary supplements containing omega-3 fatty acids appeared to reduce the rate of cognitive decline in people with the mildest Alzheimer's disease. Omega-3 didn't seem to slow the progression of more advanced forms of the dementia, however.(28)
- In pets, improves the coats and skin.
Omega-3s in Foods
For healthy adults with no history of heart disease, the American Heart Association recommends eating fish at least twice weekly. In particular, fatty fish are recommended, such as anchovies, bluefish, carp, catfish, halibut, herring, lake trout, mackerel, pompano, salmon, striped sea bass, tuna (albacore), and whitefish. It is also recommended to consume plant-derived sources of α-linolenic acid, such as tofu/soybeans, walnuts, flaxseed oil, and canola oil. Potentially harmful environmental contaminants such as mercury, dioxins, and PCBs are a significant consideration.
Amounts of EPA and/or DHA in fortified foods and beverages usually contain only very small amounts, about 50 to 100 mg per serving which is much lower than that found in a serving of fish or in a traditional fish oil supplement.
Omega-3 fatty acids are used in some infant formulas, although effective doses are not clearly established. Ingestion of fresh fish should be limited in young children due to the presence of potentially harmful environmental contaminants. Fish oil capsules should not be used in children except under the direction of a physician.
The Benefits of Fish Oil Supplements
Fish are known to accumulate toxins such as mercury, dioxins, and PCBs. Fish oil supplements, if manufactured with quality controls, do not contain these toxins.
Prescription Fish Oil Supplements
Recently a prescription fish oil supplement, Lovaza, has been tested and approved by the FDA. Lovaza is for adults and is to be used along with a low-fat and low-cholesterol diet to lower very high triglycerides (fats) in the blood. It is called a lipid-regulating medicine and is made of omega-3 fatty acids.
One capsule yields more than twice the concentration of both EPA and DHA than most brands available over-the-counter. Each 1-gram capsule of LOVAZA contains at least 900 mg of the omega-3 fatty acids. The usual therapeutic dose of LOVAZA is 4 capsules to be taken all at once or divided into two doses, two capsules two times daily, which is the equivalent of 3,600 mg of Omega-3 fatty acids per day.
Lovaza is not for women who are pregnant or breastfeeding. If you are allergic to fish, you should not take LOVAZA.Talk to your doctor about any medications you are taking, especially those that may increase your risk of bleeding. Possible side effects include burping, infection, flu-like symptoms, and upset stomach. The Lovaza website lists more about side effects and precautions.
Over-the-Counter Fish Oil Supplements
There are many fish oil supplements available over-the-counter, but the problem is that most herbs and supplements have not been thoroughly tested by the FDA for purity and quality and unfortunately there is a lack of consistency in dose and quality of many of these products that appear on the market. In fact, what appears on the label may not necessarily be in the bottle.
Contamination can also been an issue, because fish can accumulate toxins such as mercury, dioxins, and PCBs. One independent company, that is used by many health care professionals, is ConsumerLab.com. It provides independent testing results online about vitamins, supplements, and nutrition products to consumers and healthcare providers. They have apparently recently completed testing of 57 different fish oil products sold in the U.S. claiming to contain EPA and/or DHA and tested them for their levels of omega-3 fatty acids, mercury, lead, PCBs, and signs of decomposition. They found varying levels of quality and these results are available online for an annual subscription fee.
Precautions about Fish Oil Supplements
Taking fish oil supplements should be done in consultation with your physician. High intakes could cause excessive bleeding in some people. Of particular concern are people expecting to undergo surgery, or those with bleeding disorders such as hemophilia, and those taking blood thinners, such as Coumadin (warfarin) heparin, Lovenox, anti-platelet drugs, such as Plavix (clopidogrel); and nonsteroidal anti-inflammatory drugs, such as ibuprofen (Motrin, Advil) or naproxen (Naprosyn, Aleve), or even aspirin.
Small reductions in blood pressure (2-5 millimeters of mercury) with intake of omega-3 can occur. Caution is warranted in patients with low blood pressure or in those taking blood-pressure lowering medications.(30)
Fish oils are best tolerated when taken with meals, and, if possible, should be taken in divided doses such as dividing the total dose in half and taking it twice daily.
How much is enough?
In the U.S., optimal intake levels for EPA and DHA are still not defined, and a Daily Value (DV) has not been established for these nutrients. Various expert recommendations range from 500 mg to 3,600 mg per day, depending on the health status of each individual.
The World Health Organization and governmental health agencies of several countries recommend consuming 0.3-0.5 grams of daily EPA + DHA and 0.8-1.1 grams of daily α-linolenic acid.(30)
A daily dose, (four capsules of the prescription fish oil, Lovaza) provides 3,600 mg of Omega-3 fatty acids per day, but this is a therapeutic dose intended to lower very high triglycerides (fats) in the blood.