Fish and fish oils are the main dietary sources of omega-3 polyunsaturated fatty acids. Omega-3 fats are known as essential fatty acids. Since we cannot make them in our body, it is important that we get them from our diet.
The problem is, most North Americans don’t get enough of these omega-3 foods. To make matters worse, you are consuming an excess of omega-6 fats, which are found in vegetable oils and many processed foods. This high omega-6 to omega-3 imbalance leads to inflammation, which is linked to many chronic diseases and is believed to be a major driver of the aging process.
In the 1970s, Danish epidemiologists found that heart disease was virtually non-existent in Inuit populations who consumed high amounts of omega-3 fats from cold water fish.
This led to extensive research on the role of fish oils in heart disease and other diseases. The two best-studied omega-3 fats are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both of which have anti-inflammatory properties and help promote healthy aging and disease prevention.
Conditions That Can Benefit From Fish Oils
1. Joint health and arthritis
There is a common belief that fish oils “lubricate” the joints, and while this is a somewhat oversimplified explanation, omega-3 fatty acids appear to be beneficial for joint health. Osteoarthritis is a chronic inflammatory disease that increases with age. Fish oils can reduce pain and inflammation. In one study, eight weeks of EPA and DHA supplementation significantly improved knee function in people with knee osteoarthritis.
The most common and well-researched uses of fish oils are in the prevention and treatment of cardiovascular disease. EPA and DHA have been shown to help lower blood pressure, reduce triglycerides, and decrease blood clotting. While both omega-3 fats are essential, DHA appears to be particularly beneficial for cardiovascular disease and arteriosclerosis (hardening and narrowing of the arteries).
The brain is heavily focused on EPA and DHA, and it appears that consuming adequate DHA mitigates age-related cognitive decline. One study found that supplementing with DHA for 12 months significantly improved short-term memory in the elderly with mild cognitive impairment, while a separate study concluded that supplementing with EPA and DHA improved mood in adults over 65 with mild cognitive impairment improved.
When we think of strong bones, calcium is the nutrient that first comes to mind. However, there is more to bone health than our mineral stores, and it turns out that chronic inflammation is a leading cause of osteoporosis. Therefore, it makes sense that the anti-inflammatory effects of omega-3 fatty acids can help protect against osteoporosis and low bone mass. Research in this area is still limited, but studies have shown that higher omega-3 intake is linked to higher bone mineral density and grip strength, and may increase muscle protein synthesis, which is useful in the prevention and treatment of sarcopenia.
5. Aging and telomere length
Telomere length is a marker of biological aging, and slowing down this process may be one of the keys to slowing down the aging process. The researchers found that those with the highest EPA and DHA blood levels had the slowest rate of telomere shortening. Another study found that those with the lowest EPA and DHA blood levels had smaller brain volumes and vascular patterns of cognitive impairment.
How to choose the right fish oil
It can be overwhelming to choose between the myriad of options offered by omega-3 supplements. Since not all fish oils are made equal, here are some common questions and considerations to help you decide which type is best for you.
Although more research is needed to determine specific dosages, men and women 60 and over should aim for at least 500 mg EPA and 500 mg DHA as part of a healthy aging plan.
Fish oil against cod liver oil
Although both are derived from fish, fish oil and cod liver oil have some key differences. Fish oil is made from the body of fish and is a highly concentrated source of EPA and DHA. Cod liver oil doesn’t contain as much EPA and DHA, but it does contain fat-soluble vitamins D and A.
Krill oil is touted as a better absorbed form of omega-3 fats and contains the natural antioxidant astaxanthin. The downside is that it contains significantly less EPA and DHA than other fish oils, and the cost tends to be much higher. Added to this are concerns about the sustainability of the krill harvest and it is difficult to choose krill oil over other forms of fish oils.
Fish oils and blood clotting
Because fish oils are known to reduce blood clotting, there is concern for those taking blood thinners or known bleeding disorders. However, one study showed that the use of high-dose fish oils (4 g / day) did not affect bleeding in patients taking aspirin or warfarin. Another smaller study reported that fish oil supplements did not affect clotting time in patients on long-term therapy with warfarin. There is a case report of fish oils interacting with warfarin therapy. So, if you are taking anticoagulants, it is a good idea to speak to your doctor before taking any fish oils.
Fish oil quality and purity
One problem with fish oil supplements is heavy metal contamination. When choosing a fish oil, it is imperative that the company provide a certificate of analysis (preferably from an independent third party) that checks for contaminants such as heavy metals, dioxins and polychlorinated biphenyls (PCBs).
Metals accumulate more often in larger fish such as tuna and salmon, less in small fish such as anchovies and sardines. Since polyunsaturated fats are prone to oxidation, fish oils can easily go rancid. A strong “fishy” taste or smell is a sign of rancidity. To ensure high quality control standards, verify that your fish oil has been tested by the IFOS (International Fish Oil Standards) program or a similar independent third party laboratory.
If you look closely at a fish oil label, you will likely see the totals for omega-3, EPA, and DHA listed. A higher quality product will be high in EPA and DHA compared to omega-3. Since most of the research is done on EPA and DHA, we’d like to get this out of a fish oil supplement.
Food sources for omega-3 fatty acids
Those who eat cold water fish (e.g., salmon, tuna, sardines) two to three times a week are likely to meet their omega-3 quota. You may also have heard that flaxseed oil and other vegetarian foods are good sources of omega-3 fats, and while this is true, most plant sources are high in alpha-linolenic acid (ALA), which does not easily convert to EPA as well DHA in our body.
While flaxseed and other herbal sources can have additional health benefits, they’re not the best source of EPA and DHA.
Research shows that the omega-3 fats EPA and DHA are essential for healthy aging and are particularly beneficial for cardiovascular health, cognition, and memory. For healthy adults who don’t consume cold-water fish at least twice a week, a quality supplement containing at least 500 mg of EPA and DHA appears to be beneficial.
Those at higher risk of cardiovascular disease or cognitive impairment may benefit from a higher dose. However, it is best to discuss this with a licensed healthcare practitioner.
Dr. Tomah Phillips is a licensed naturopath at Kinetic Patterns Medical Clinic in Vancouver, BC. In addition to clinical practice, Dr. Tomah Biomedicine at the Boucher Institute of Naturopathic Medicine. He has a BSc. in Physiology from McGill University and a naturopathic degree from the Boucher Institute of Naturopathic Medicine.
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