The China Study: The Most Comprehensive Study of Nutrition Ever Conducted and the Startling Implications for Diet, Weight Loss and Long-Term Health

by T. Colin Campbell

higher levels of blood hormones such as estrogen. These hormone levels remain high throughout the reproductive years if consumption of a diet rich in animal-based food is maintained. Under these conditions, age of menopause is deferred by three to four years,I thus extending the reproductive life from beginning to end by about nine to ten years and greatly increasing lifetime exposure to female hormones. Other studies have shown that an increase in years of reproductive life is associated with increased breast cancer risk.35, 36 This network of relationships becomes still more impressive. Higher fat consumption is associated with higher blood levels of estrogen during the critical years of thirty-five to forty-four yearsIII and higher blood levels of the female hormone prolactin during the later years of fifty-five to sixty-four years.III These hormones are highly correlated with animal protein intakeIII and milkIII and meat.II