for a long time the medical community has said to limit the amount of red meat you eat b/c it's linked to heart disease and cancer. the reality is that fresh red meat is good for you, even necessary. the myth evolved out of bad science in the 50's that lumped red meat in with processed meats (deli meats) and didn't consider other dietary factors as well.
it's a great read if you're interested. if not, go have a steak anyways.
http://www.westonaprice.org/food-features/its-the-beef
The only claim that can be made against beef as a cause of heart disease is that some studies have shown beef consumption to temporarily raise cholesterol levels in short term feeding experiments. Other studies have shown that beef consumption, including beef fat consumption, lowers cholesterol levels. But even if all studies show that beef consumption raises cholesterol levels, the only conclusion you can draw isso what? There is no greater risk of heart disease at cholesterol levels of 300 than at 180, and people with cholesterol levels below 180 are at greater risk of death from other causes, such as cancer, intestinal diseases, accidents, violence and suicide.5 In other words, it's much more dangerous to have cholesterol levels that are too low than cholesterol levels that are too high
We don't know what our limits are, so to start something with the idea of being limited actually ends up limiting us.
Ellen Langer