Originally posted by twhitehead
I get: 152.0 per 100,000 men
So with fish oil it becomes: 217 per 100,000 men.
Considering that the study had under 2000 men, of which about 3 would have normally had prostate cancer I wonder if the sample size was large enough. Anyone know enough statistics?
Look up "power (statistics)" on Wikipedia. It's not simple to calculate, and depends on details of how they did their study. The effect is fairly small, but 2,000 is fairly big by the standards of studies, some phase II trials have as few as 15 people in each arm. They've probably got enough power to make the claim. I'll see if I can access the original paper or not.
Edit: The paper is free to download here: http://jama.jamanetwork.com/data/Journals/JAMA/5009/JRV50027.pdf
I'll tell you what I think when I've read it.
Edit 2: This is not the right paper. (But has good methods and finds no evidence that omega-3 either prevents or causes cancer).
Edit 3: Here is the correct reference: http://jnci.oxfordjournals.org/content/early/2013/07/09/jnci.djt174.abstract?sid=4283f806-047c-4f33-9646-cbaa88c24e65
It costs $32 for 1 days access to the paper. So I'm only reading the abstract.
Edit 4: This is back to front. They found 863 people with prostate cancer and looked at their blood serum. More people who had cancer had high levels of omega-3. They've shown an association, but it could be that people with prostate cancer are at high risk of having omega-3 in their blood rather than the other way round. I'd avoid reading too much into this study. A better design would be to put 10,000+ people on a long term trial where one lot take omega-3 pills and the rest take smarties, and see who does better.