The science of endocrinology has taught us that organs whose growth and function are under hormonal control will become malignant from excessive hormone stimulation. Based on the science of endocrinology, breast cancer is defined as a hormonal imbalance involving the over stimulation of cells by growth and reproductive hormones, and usually develops in women in their middle ages or older. A time at which, both growth hormones and reproductive hormones should be declining.
Since, breast cancer is not inherited nor the result of an infection it is most probable that breast cancer more accurately reflects the total accumulation of hormone stimulating dietary habits over one’s lifetime.
With respect to dietary sources, dairy is unique because it contains substantial amounts of both growth and reproductive hormones.
In 1986 a study of 1,010 breast cancer cases in France reported a positive association between the risk of breast cancer and the daily consumption of whole milk. In 1989 a study in Italy set out to investigate the association between breast cancer and the intake of animal fat. A considerable reduction in the risk of breast cancer was found in women who were consuming total fat intake below 28% of the total calories.
In this article the word dairy was not used in the title, or in the author’s introductory abstract of the article, or in the author’s summary of the article, since a study of dairy was not the purpose of the experiment. However, the author could not keep from commenting that the data results from his study reveals a positive association exist between breast cancer and the consumption of dairy.
In 2002 a study in Uruguay investigated an association with dairy intake and cancer. Out of 311 women studied 111 women had breast cancer. In this study whole milk was associated with a significant increase in the risk of breast cancer, whereas non-fat yogurt was not.
In 2003 a large population study took place in Boston. Premenopausal women were found to have an association between the intake of fat and the risk of breast cancer. The authors consider the risk of breast cancer to be only slightly increased. Nevertheless, among the food items studied it was dairy and red meat that was associated with an increased risk.
During this time, parallel research groups were focusing on what components in dairy might be contributing to the disease. In one study, 1,893 women were treated for invasive breast cancer and followed for 11 years. During this period, 349 women experienced a recurrence and 189 women died from breast cancer. Dairy was associated with higher risk of mortality from breast cancer; and elevated estrogen hormone levels could be a contributing factor.
In 1995 the first epidemiological confirmation of a link between estrogen and breast cancer took place in New York City. This study group set out with the sole purpose of assessing the risk of breast cancer in relation to the blood levels of estrogens in women. All women who developed breast cancer had higher blood levels of estrogen compared to those women who remained cancer free.
In 2006, 418 breast cancer patients are found to have higher levels of estrogens compared to women without cancer. Interestingly, the risk of breast cancer was not dependent of a family’s history of breast cancer, but more dependent on a women’s overall lifetime exposure to estrogens and dietary habits.
Subsequent to these earlier studies, biochemists and geneticists have identified estrogen binding receptor sites on cell membranes from specimens’ of breast cancer tissues. The mere presence of these estrogen receptors can generally be taken as a strong indication that breast cancer must be estrogen dependent. Indeed, DNA damage from estrogen is now considered to be the silent source of breast cancer and estrogen has been defined as a cancerous agent.
Any dietary habits that could decrease intake of estrogens, decrease blood levels of estrogens, or decrease endogenous production of estrogens could reduce the risk of developing breast cancer.