To be certain one risk factor is real, you need to know that there isn't another explanation for an apparent link between one food (or drug, or other lifestyle factor) and a disease. The completely discredited hysteria over MMR and a possible link with autism is a case in point. Autism was rising, something had to be to blame and a group of maverick scientists, ably abetted by the media, chose MMR as the scapegoat.
This is a companion discussion topic for the original article at https://patient.info/news-and-features/how-much-red-meat-should-you-eat