Fish oil is generally considered safe, however as with all supplements, it is best to seek the advice of a pharmacist or GP before commencing. High doses of fish oil may increase the risk of blood thinning especially if taken with blood-thinning medications such as warfarin or used in individuals with a history of bleeding. Fish oils are also known to cause a variety of digestive problems such as flatulence, bloating, reflux and nausea. It is also important to not confuse fish oils with fish liver oils (eg. Cod liver oil) as these oils contain Vitamin A, which in large doses can cause serious side effects, particularly during pregnancy.
Fish Oils & Omega-3 Fatty Acids
Fish oil is a natural product derived from the tissues of oily fish such as sardines and salmon. It contains high proportions of two nutritionally important omega-3 fatty acids, eicosapentanoic acid (EPA) and docosahexanoic acid (DHA), also known as ‘long chain omega-3s’. Omega-3s are a polyunsaturated fat which is an essential nutrient required for cell membrane health, and cellular communication. EPA has been found to be beneficial in reducing inflammation and also in supporting a healthy cardiovascular system. DHA is particularly important in brain growth and visual development of the unborn baby, as well as playing a role in reducing triglycerides in the blood thereby promoting healthy cardiovascular function. Research has shown that omega-3s protect against heart rhythm disorders and support blood vessel function.
Anti-inflammatory properties of omega-3s may help in certain conditions such as rheumatoid arthritis, back and neck pain. Studies have shown that using regular intake of fish oil have significantly improved pain control and quality of life. Fish oil works primarily by reducing various pro-inflammatory mediators such as cytokines and leukotrienes, which are responsible for transmitting pain signals. Several studies show that a regular intake of fish oil supplements decreased the patient’s requirement of medicinal pain killers. It is recommended that up to 5000 mg of fish oil should be taken per day in 3 divided doses in order to provide adequate pain relief. Furthermore, it is important that fish oil is taken on a continuous basis for a period of at least 2-3 months to obtain beneficial effects.
Some of the strongest evidence for the use of fish oil is in the prevention and management of cardiovascular disease. Several large-scale studies indicate beneficial effects on cholesterol, platelet function, and blood pressure. Although the exact mechanism of action is unknown, it is understood that the anti-inflammatory properties of fish oil help relax artery walls and prevent the formation of blood clots in these arteries. Three large, controlled trials showed a 19 percent to 45 percent reduction in cardiovascular events when participants were supplemented with omega-3 oils. In a particular study, it was found that in patients with triglyceride levels above 500 mg/dL, approximately 4000 mg per day of omega 3 fish oil reduced triglyceride levels by 45 percent. Data from these trials indicate those without cardiovascular disease should consume at least 500 mg of fish oil daily and those with existing disease should have a daily intake of at least 1 g.
Several recent studies in 2010 suggest that EPA is the chemical component that may also improve symptoms of depression. Essential fatty acids are critical for proper functioning of the brain and reduced levels of EPA and DHA are often observed in patients with bipolar disorder and depression. While the exact mechanisms are unknown, one pathway is based on the knowledge that cell membranes are partially comprised of omega-3 oils. Omega-3 oils appear to soften these cell membranes, making it easier for brain chemicals such as serotonin to regulate mood. Findings from recent studies show that an intake of 3000 mg of fish oil daily may lead to reduced levels of chronic depression, especially in women. Furthermore, a Cochrane Review reveals fish oil’s positive role in mood and psychiatric conditions.
There are concerns that many Australians are not consuming sufficient amounts of fish to obtain the maximum benefits of omega-3s. The National Health and Medical Research Council recommend a daily intake of 610mg of omega-3s for men and 430mg for women. This is approximately equivalent to 2-3 serves (150g) of oily fish per week. For individuals who do not eat a lot of fish, fish oil supplements may be ideal. Oily fish rich in omega-3s include Australian and Atlantic salmon, blue-eye trevalla, blue mackerel and gemfish.
Tips on ways to reach the recommended daily intake of omega-3s include: