A vegan diet can reduce pain, reverse or prevent disease and lower health costs, while eating animal protein can raise the risk of cardiovascular disease and some cancers, says T. Colin Campbell, a professor emeritus of nutritional sciences at Cornell University. Nancy Rodriguez, a nutrition professor at the University of Connecticut, says a balanced diet that includes dairy and protein is healthier overall than a vegan plan that can lead to nutrient deficiencies. The Wall Street Journal (9/18)