I’ve written previously about fish oil (see here and here). The preponderance of evidence suggests to me no benefit from taking fish oil (or its main ingredient, n-3 fatty acids). Fish oil does lower blood levels of triglycerides (harmful fats, somewhat similar to bad cholesterol). However, the purpose of doing this is to try to make you healthier. If the sole effect is to change a lab value (blood triglyceride levels) without having any impact on health, there isn’t any value.
As of today, there is more evidence that fish oil is no better than placebo. A study published in the New England Journal of Medicine evaluated 12,513 patients who were at high risk for cardiovascular disease. These individuals were randomized to take either n-3 fatty acids of placebo/olive oil. They were subsequently followed to determine the rates of death or hospitalization for cardiac reasons. The rates were 11.8% in the n-3 fatty acid group and 11.9% in the placebo group – essentially no difference at all. (For those interested in the statistics, the p value was 0.58).
This article in the NEJM is just one of several. By my count, this is the third large, well-done study to be published recently that shows the same thing: no benefit.
Selling fish oil is big business. There are two public companies (Omthera and Amarin) that are solely dedicated to developing or selling omega fatty acids. Glaxo sells the market leading fish oil product, Lovaza, with US sales of almost $1 billion per year. At what point do patients and/or insurance companies ask why they are paying $180 per month for something with no proven medical benefit? That is one expensive placebo.
source: n–3 Fatty Acids in Patients with Multiple Cardiovascular Risk Factors (NEJM)