Strong correlation vs. causation vibes here. It could well be that ejaculation helps prevent prostate cancer, but it could just as well be that men who are by

Strong correlation vs. causation vibes here. It could well be that ejaculation helps prevent prostate cancer, but it could just as well be that men who are by nature more likely to get prostate cancer also need less frequent ejaculation and that ejaculation has nothing to do with causing the cancer.