From Dr. Fuhrman's book Disease-Proof Your Child:
Worldwide, there is a linear relationship between higher-fat animal products, saturated fat intake, and breast cancer.1 However, there are areas of the world even today where populations eat predominantly unrefined plant foods in childhood and breast cancer is simply unheard of. Rates of breast cancer deaths (in the 50-to-70 age range) range widely from 3.4 per 100,000 in Gambia to 10 per 100,000 in rural China, 20 per 100,000 in India, 90 per 100,000 in the United States, and 120 per 100,000 in the United Kingdom and Switzerland.2
Experimental evidence suggests that the susceptibility of mammary tissue to carcinogens is greatest in the childhood and teenage years. The time during breast growth and development is a particularly sensitive period in a woman’s life, affecting the later development of breast cancer in adulthood. Teenagers who eat more high-fiber, high-antioxidant foods such as fruits, vegetables, and nuts have less occurrence of benign breast disease, the precursor marker of breast cancer.3
Of particular concern is the pattern linking breast cancer to the early age of puberty we are witnessing in modern times. The average age of onset of menstruation in the nineteenth century was seventeen, whereas in the last fifty years in Western industrialized countries, such as the United States, the average age of onset of menstruation is twelve. The over-nutrition and heightened exposure to animal products, oils, and saturated fats4 earlier in life induces a rapid earlier growth and an earlier puberty. Earlier age of puberty increases one’s lifetime exposure to estrogens and is associated with a higher incidence of breast cancer years later.
Cohort studies, which follow two groups of children over time, have shown that the higher consumption of produce and protein-rich plant foods such as beans and nuts is associated with a later menarche, and the higher consumption of protein-rich animal foods—meat and diary—is associated with an earlier menarche and increased occurrence of adult breast cancer.5
Early puberty is strongly associated with breast cancer, and the occurrence of breast cancer is three times higher in women who started puberty before age twelve.
A recent intelligently devised study investigated all twin sisters in northern Europe and England where on developed breast cancer and the other did not. The researchers found 400 cases of breast cancer in only one twin occurring before the age of fifty. They concluded that childhood growth before puberty (the twin with cancer was most often taller at age ten) and developing breasts before her cancer-free sister was the primary marker of the increased risk.7
Another recent study published in the New England Journal of Medicine looked at 1,811 sets of twins and reported that for identical twins with cancer, the first twin to reach puberty was five times more likely to develop cancer at an earlier age.8 The link was even stronger when menstruation began before the age of twelve. Jo Ann Mason, M.D., of Harvard’s Brigham and Woman’s Hospital said the implications of the study are worrisome given the gradual decline in the age of puberty in the United States and the rise in childhood obesity.
Physicians are seeing more and more girls with precocious sexual development, even before today’s average age of twelve, and medical studies confirm that the trend is real and getting worse. How early are our children developing today? At age eight, almost half black girls and 15 percent of white girls start developing breasts or pubic hair. At age nine, those numbers change to 77 percent of black girls and a third of white girls.9
The critical questions, which our nation generally ignores, are how harmful is this and what can be done about it? Obviously, this anomaly in human history where girls mature so young is threatening. We will undoubtedly see breast cancer occurrence continue to climb as today’s children reach adulthood. Cancer occurrence has been shown to occur many years after dysplastic changes occur to the breast, and these changes are often viable in teenagers.
It is of particular importance to note the most significant age range where dietary intake most critically affects the age of puberty. A 1999 study published in the American Journal of Epidemiology followed children since birth and reported that the girls who consumed more animal products and fewer vegetables between ages one and eight were prone to early maturation and puberty, but the strongest predictor was a diet rich in animal protein before age five.10