When combined with smoking, these risks skyrocket. Not surprisingly, vegetarians, whose diets easily meet these requirements, are at the lowest risk for cancer. Vegetarians also have stronger immune systems. German researchers recently discovered that vegetarians have more than twice the natural killer cell activity of meat-eaters.12 Natural killer cells are specialized white blood cells that attack and neutralize cancer cells. Also, vegetarians tend to eat more soy products than meat-eaters.
Soybeans contain many substances that are anticarcinogens, including lignans and phytoestrogens.
A diet that is rich in soybeans may be one reason for the lower incidence of breast cancer in Asia. It also minimizes or excludes alcohol. The best diets are pure vegetarian diets. Risch HA, Jain M, Choi NW, et al. Dietary factors and the incidence of cancer of the stomach.