We know that because when healthy people move to countries that have poor diets, they take on the diseases of the country they move to.
This video comes from the 2009 VegSource Healthy Lifestyle Expo.
Cornell University professor T. Colin Campbell Phd presents the overwhelming evidence showing that animal protein is one of the most potent carcinogens people are exposed to.
You paid for the research. The government and the food industry with an assist from the Cancer Society has kept this information under wraps.