I think that the important thing is to distinguish between two distinct types of medical research.
Firstly there is an awful lot of research reported in the media, looking at why certain races and cultures experience more or less of particular types of cancer. This often focuses on diet and lifestyle.
For example, I think it is Okinawa, or some other offshore Japanese island where most people live to be 90+ maybe 100+, and they have a diet of fish and vegetables, they of course also have a different gene pool but the media often ignore that.
Then there is the apparent link with vitamin D, focusing upon the fact that there is a greater risk of Scandinavian and Canadian men getting prostate cancer than men in more southerly latitudes, suggesting lack of sunshine causes prostate cancer.
The thing that these lines of research have in common is that they are looking at lifestyle since birth, and while they may be very interesting they don't help you or me now, because we have already completed most of our lives, drinking beer, eating fish and chips etc, we can't turn the clock back.
So you have to ask yourself what can I do now, what dietary changes will effect my health at this late stage?
When I was first diagnosed, I hit on Dr Jane Plant's diet, dairy free, indeed vegan seemed to make a lot of sense. But the root of her diet is the observation that Chinese women who have spent their entire lives dairy free don't get breast cancer. In fairness to her, God rest her soul, Jane Plant's research went well beyond that point, and she provided a logical theory to justify us going dairy free even at this late stage in our lives.
The problem I found with sticking rigidly to the Jane Plant diet is that, it is high in carbs, and there is lots of sugar in bread, potatoes, rice etc. It might be a coincidence but I was diagnosed diabetic when I was on that diet.
The other thing to consider is that many men on HT find that if they are not careful they put on weight, I certainly did initially.
So I have now sort of developed my own crazy diet which is a sort of marriage between Jane Plant and the Atkins diet. I drink lots of green tea, I eat meat and fish, I need plenty of green veg, beans and onions to avoid constipation. Most days I try and be carb free, certainly I rarely eat bread, potatoes, rice or pasta.
But I am not by any sense a purist, a couple of years ago there was a thread on here about the ideal breakfast, Lyn Eyre and I shared the ultimate, low calorie, low fat, low sugar, low salt, low carb breakfast, it's called black coffee and a cigarette!
So my advice is to take notice of all this research, but still have a little of what you fancy. If you or I emigrated to that Japanese island and changed to a diet of fish and veg, we still wouldn't live as long as the locals, because it is already too late for us, we should have been doing that all of our lives.