"Suppressing the engine-of-aging enzyme TOR (Target of Rapamycin) by reducing intake of leucine–rich animal products, such as milk, may reduce cancer risk."

One amino acid in particular, leucine, appears to exert the greatest effect on TOR. In fact, just cutting down on leucine may be nearly as effective as cutting down on all protein. Where is leucine found? Predominantly animal foods: eggs, dairy, and meat (including chicken and fish). Plant foods, such as fruits, vegetables, grains, and beans, have much less.

“In general, lower leucine levels are only reached by restriction of animal proteins.” To reach the leucine intake provided by dairy or meat, we’d have to eat nine pounds of cabbage—about four big heads—or 100 apples. These calculations exemplify the extreme differences in leucine amounts provided by a conventional diet in comparison to a plant-based diet. The functional role of leucine in regulating TOR activity may help explain the extraordinary results reported in the Cornell-Oxford-China Study, “since quasi-vegan diets of modest protein content tend to be relatively low in leucine.”