Many observational studies associate prostate cancer with markers of metabolic syndrome. Which gives us the omega3/trans fat paradox, well discussed in several places around the net.
Here's a similar prostate paradox.
How come these two exceptions buck the trend? Here's a random thought:
Let's assume prostate cancer is related to chronic hyperinsulinaemia, a reasonable idea, ie it is "metabolic syndrome of the prostate".
Conversely, castration is a component of conventional prostate cancer treatment.
Getting to the chemical-castration stage of metabolic syndrome might well be prostate cancer protective.
Omega 3 fats probably slow progression of metabolic syndrome, trans fats probably accelerate it.
If you want to get to the castration level of metabolic syndrome as fast as possible, to maximise this prostate benefit, never forget to ask for your favourite lipotoxin by name.
For metabolic castration you should always ask for Crisco.
Alternatively I have a couple of bricks available. It's an old anaesthetist's joke:
Surgeon: "I don't need to use anaesthesia for castration."
Anaesthetist: "Really, what's your technique?"
Surgeon: "I have these two bricks and I smash them together on the testicles."
Anaesthetist (aghast): "Doesn't that hurt?"
Surgeon: "Only if you get your thumbs in the way."