How about iron overload??? I love red meat, but I recently read an article by Ray Peat mentioning how iron overload could be a precursor to many diseases, especially in men. I know donating blood can help, but I am not to fond of doing it often.
The only things that my body has problems with and the list of things that are bad for you- only come from grains and industrial agriculture, not from red meat or animal products. I eat a lot of veggies, more than so-called vegetarians who load up on grains and junk food (watch them eat chips, crackers and cakes).