Fish oil: Separating fact from fiction

Albert Barber | posted June 28, 2012 |

Fish oil from food sources, or in supplements, is widely touted to cure or prevent many human ailments. Unlike prescription drugs, vitamins and other supplements do not require FDA approval for effectiveness.

Therefore, it is very important to understand how the benefits of these products compare to risks for individual patients. One of the best sources, in my opinion, is the Natural Medicines Comprehensive Database published by Therapeutic Research Faculty.

Fish oil, also known as marine fish oil and omega-3 fatty acids, is used to treat high cholesterol, high triglycerides, rheumatoid arthritis, osteoporosis, psoriasis and many other conditions. Omega-3 supplements are generally well tolerated, but can cause a fishy aftertaste, heartburn, nausea, loose stools and rash. Taking with meals or freezing the capsules seems to reduce these side effects for some people. Total daily dose should be limited to 3 grams per day. Higher doses can increase the risk of bleeding and suppress the immune system.

Fish oil has been determined to be EFFECTIVE for:

• High triglycerides – a 20-50% reduction has been shown for fish oil from dietary sources or supplements.

• However, fish oil supplements in doses up to 4 gm/day do not seem to be as effective as the prescription drug, gemfibrozil (Lopid) 1200mg/day. 

• A specific fish oil preparation, Lovaza, is a prescription drug and is FDA-approved for treating high triglycerides (levels of 500mg/dL and above) in conjunction with dietary modifications.

Fish oil has been shown to be LIKELY EFFECTIVE for:

• Cardiovascular disease – Consuming fish oil from dietary sources, two servings of fatty fish per week, seems to reduce the risk of developing cardiovascular disease (primary prevention). A 23% reduction in overall mortality and a 32% reduction in death from cardiovascular causes has been shown. 

• This benefit appears to be limited to broiled and baked fish but not fried fish or fish sandwiches.

Fish oil has been shown to be POSSIBLY EFFECTIVE for:

• Asthma, diabetic nephropathy, elevated lipids, heart failure, hypertension, osteoporosis, psoriasis, rheumatoid arthritis and stroke risk.

Like many nutritional supplements, fish oil from dietary sources (i.e. fatty fish like herring, mackerel, salmon, sardine and trout) is preferred, but omega-3 fatty acids in oral supplements are a reasonable alternative for primary prevention (prevention of disease). If you have already suffered a cardiovascular event (i.e. stroke or heart attack), contact your physician to see what treatment is best for you for secondary prevention.