Many of us already take fish oil for its heart benefits, but here is another reason to consider taking it:
I've seen research going back to 2008, so this is not a recent discovery. However, there are now clinical trials recruiting to test a combination of Vitamin D and Fish Oil. Preliminary information indicates a 32% reduced rate of invasive ductal cancer (so I am assuming either they're not measuring other types or it has no effect).
Fish Oil is a fairly safe supplement. You might not want to wait for the results of the clinical trial as that can take years. Alas, the article doesn't say how much to take. I think I'll stick with 1 gram a day for now.