A recent study in Japan resulted in EPA (a fatty acid found in fish oil) being approved for the treatment of hyperlipidemia and peripheral artery disease, and in Europe, for reduction of mortality after a heart attacks.
The study mentioned above, included over 18 though individuals with the mean age of 61 and whose average total cholesterol was 251. Individuals received 600mg of EPA three times per day or a popular lipid lower medications (a statin such as lipitor or crestor). Most of these individuals had no history of cardiovascular disease.
After nearly 5 years of observation, the group taking the EPA had significantly fewer cardiovascular events.
Note: this study did not look at prevention of primary cardiovascular disease. It did not study individuals in the US where fish and fish oil products are consumed less and where lifestyle differs significantly. In other words, it is difficult to say this is significant for those of us in the US.
That said…I do eat fish, and will continue to take EPA.