“There’s also some indication that replacing carbohydrate with plant rather than animal foods has special health benefits. Among approximately eighty thousand women in the Nurses’ Health Study consuming lower-carbohydrate diets, high consumption of vegetable protein and fat was associated with a 30 percent lower risk for heart disease over twenty years, whereas high consumption of animal protein and fat appear to provide no such protection.

One explanation for this finding is that the relative amounts of amino acids in animal protein stimulate more insulin and less glucagon release than those in plant protein – a hormone combination that has detrimental effects on serum cholesterol and fat-cell metabolism. Other possible downsides of a modern, animal-based diet include a less healthful profile of dietary fats, excessive iron absorption (especially for men), and chronic exposure to hormones, preservatives, and environmental pollutants.”