What are they?
Fish oil contains two important omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The other group of essential fatty acids are omega 6s.
Omega-3s and Omega-6s are fatty acids that the human body must get from diet. Small amounts of EPA and DHA can be made from another essential fatty acid: Alpha Linolenic acid (ALA). ALA is a true “essential” omega-3 because the human body cannot produce ALA on its own.
Vegetarian sources, such as walnuts, flaxseeds, and spinach contain ALA. Sources of omega-3 fatty acids include salmon, sardines, herring, mackerel, black cod, bluefish, and algae.
Omega 6s, however, are numerous in modern diets. They are found in seeds and nuts and the oils extracted from them. Refined oils are used in cookies, crackers, many packaged foods, and fast foods. Soybean oil alone is now so ubiquitous in fast foods and processed foods that it comprises an astounding 20 percent of the calories in the American diet.
Over time, the American diet has had a much higher ratio of omega 6s to omega 3s, potentially the cause of many health issues.
Why do we need Omegas?
EPA and DHA are the building blocks for hormones that control immune function, blood clotting, and cell growth as well as components of cell membranes.
Omega-3s are known for supporting heart, brain and eye health at all stages of life. In fact, our heart, brain and eyes contain the highest content of omega-3s compared with other parts of the body.
The body does also make hormones from omega 6 fatty acids. In general, hormones derived from these two classes of fatty acids have opposite effects. Those from omega-6 fatty acids tend to increase inflammation (an important component of the immune response), blood clotting, and cell proliferation, while those from omega-3 fatty acids decrease those functions. Both families of hormones must be in balance to maintain optimum health.
With our modern diet, we get far too much of the omega-6s and not enough of the omega-3s, which is essentially pro-inflammatory. This dietary imbalance may explain the rise of such diseases as asthma, coronary heart disease, many forms of cancer, autoimmunity and neurodegenerative diseases, all of which are believed to stem from inflammation in the body. Omega 3s are also thought to reduce swelling and pain.
Are they really effective?
Fish oil is likely effective for treating:
High triglycerides. The effects of fish oil appear to be the greatest in people who have very high triglyceride levels.
Heart disease. Research suggests that eating fish can be effective for keeping people with healthy hearts free of heart disease. People who already have heart disease might also be able to lower their risk of dying from heart disease by eating fish or taking a fish oil supplement. However, for people who already take heart medications such as a “statin” and those who already eat a decent amount of fish, adding on fish oil might not offer any additional benefit. Data are conflicting on this.
They are possibly effective for improving the following conditions, though studies are conflicting:
Dry eye. Some clinical research shows that eating more fish oil is linked to a lower risk of getting dry eye syndrome in women.
Menstrual pain (dysmenorrhea). Research shows that taking fish oil, alone or with vitamin B12, can improve painful periods and reduce the need for pain medications in women with menstrual pain.
High blood pressure. Fish oil seems to slightly lower blood pressure in people with moderate to very high blood pressure. Some types of fish oil might also reduce blood pressure in people with slightly high blood pressure, but results are inconsistent. Fish oil seems to add to the effects of some, but not all, blood pressure-lowering medications. However, it doesn’t seem to reduce blood pressure in people with uncontrolled blood pressure who are already taking blood pressure-lowering medications.
Osteoporosis. Research suggests that taking fish oil alone or together with calcium and evening primrose oil slows the rate of bone loss and increases bone density at the thigh bone (femur) and spine in elderly people with osteoporosis.
Rheumatoid arthritis (RA). People who take fish oil can sometimes reduce their use of pain medications. Also, administering fish oil intravenously (by IV) reduces swollen and tender joints in people with RA.
Stroke. Moderate fish consumption (once or twice weekly) seems to lower the risk of having a stroke by as much as 27%. Eating fish does not lower stroke risk in people who are already taking aspirin for prevention.
Fish oil has been thought to be effective for many other conditions, including age-related vision loss, seasonal allergies, memory loss/dementia, improvement of asthma symptoms, eczema, prevention of cataracts, and improvement of depression symptoms. There is conflicting evidence with regard to many of the benefits of fish oil for these conditions. The jury is still out.
Are there safety concerns with taking Omega-3s?
Fish oil is likely safe for most people when taken in low doses (3 grams or less per day). There are some safety concerns when fish oil is taken in high doses. Taking more than 3 grams per day might keep blood from clotting and can increase the chance of bleeding. High doses of fish oil might also reduce the immune system’s activity, reducing the body’s ability to fight infection. This is a special concern for people taking medications that are designed to reduce their immune system’s activity and the elderly.
Fish oil can cause side effects including belching, bad breath, heartburn, nausea, loose stools, rash, and nosebleeds. Taking fish oil supplements with meals or freezing them can often decrease these side effects.
Some fish (especially shark, king mackerel, and farm-raised salmon) can be contaminated with mercury and other industrial and environmental chemicals. Fish oil supplements typically do not contain these contaminants. However, eating fish twice a week maybe better absorbed than in supplement form.
What do Omega-3s interact with?
Fish oil supplements can interact with common medications such as birth control pills, medications for treating high blood pressure, and blood thinners. Fish oil can increase the effects of both blood pressure medications (causing a drop in blood pressure) and blood thinners (possibly increasing bleeding risk).
Since Fish oil can lower blood pressure, be careful when using supplements and herbs, such as coenzyme Q10, casein peptides, L-arginine and others that also decrease blood pressure. Same goes with herbs and supplements that can slow blood clotting, such as garlic, ginger, gingko, Panax ginseng, red clover, turmeric, and others.
Remember, not all fish oil supplements are created equally. Make sure to get high quality, pure supplements. Check with your health care provider on whether (and which) fish oil supplements are right for you!
Patt Internal Medicine- A part of your health and wellness team!!
Madhavi Patt, MD