Foster has calculated that the amount of cancer can be predicted by the following equation. His use of equations also illustrates an attempt to give each of the causal factors proper weight. According to Foster, main factors are deficiency of calcium and a deficiency of selenium. Evidence favoring this hypothesis is fairly extensive and described in this chapter. More striking is the evidence coming from China where the introduction of jiangshi into the drinking water has substantially decreased the incidence of throat cancer.
Breast cancer is now epidemic.
The latest figure shows that one out of nine women will develop breast cancer. The mortality is about one-third. There are the usual genetic factors but this can not explain the rapid increase in incidence over the past 20 years. Nutrition plays a major role. It has been shown that a high fat diet causes an increase in blood estrogen levels.