I am very interested in diet and science and base what I eat mostly on what is recommended to BRCA1 women since my gene mutation is very similar. I hit pubmed on a daily basis. However I know that you can find an association with cancer risk or the opposite, benefit for most food ingredients.
Take this study
Is everything we eat associated with cancer? A systematic cookbook review
Ingredients were randomly selected from a cookbook, they were veal, salt, pepper spice, flour, egg, bread, pork, butter, tomato, lemon, duck, onion, celery, carrot, parsley, mace, sherry, olive, mushroom, tripe, milk, cheese, coffee, bacon, sugar, lobster, potato, beef, lamb, mustard, nuts, wine, peas, corn, cinnamon, cayenne, orange, tea, rum, and raisin. , so a mix of animal, plant, spice
For each the authors could find studies that show an increased risk and its opposite.
academic.oup.com/ajcn/article/97/1/127/4576988
or the big war between types of diet, the low carb agains the low fat. Every study compares a crappy diet against a healthy low something. But when they compared a healthy low carb vs a healthy low fat, no difference whatsoever
Bottomline, you can manipulate pubmed to your flavour.
Which makes my every day complicated, especially when my oncologist doesn't believe at all in diet preventing cancer, and her words " eat what you want, it doesn't make any difference" .
And people don't like to change their beliefs and opinion, be it on diet, vaccine, Trump, ....