As I discuss in detail in my recent book, A Cancer Prevention Guide for the Human Race, there are several important lifestyle and dietary factors that have been linked to cancer risk by numerous high-level research studies. Moreover, breast cancer risk, as well as the risk of several other hormone-responsive cancers in particular, appears to be especially associated with potentially modifiable lifestyle and dietary factors, including obesity, alcohol intake, smoking, lack of physical activity, high-fat diets (and diets rich in animal-based foods, specifically), as well as other modifiable risk factors.
While certain lifestyle and dietary risk factors linked to breast cancer risk have been confirmed by numerous research studies, the underlying mechanisms whereby these risk factors increase breast cancer risk has not been entirely clear. Now, a comprehensive new review of 13 prospective breast cancer public health studies sheds important light on the important topic of breast cancer prevention, and provides much-needed insight into how our own personal habits may directly increase our risk of developing breast cancer. The findings of this new cancer prevention study are scheduled to appear in the next issue of the British Journal of Cancer.
Of the 13 prospective clinical research studies that were analyzed in this report, 7 were performed in the United States, 1 was performed as part of a multinational European study, and 1 each was performed in Australia, Italy, Japan, Sweden, and the United Kingdom. Altogether, 6,291 women were evaluated in these 13 prospective public health studies.
As has been shown in many previous studies, this report confirmed that women with high levels of the sex hormones estrogen and testosterone in their blood are 2 to 3 times more likely to develop breast cancer when compared with women who have low circulating levels of these hormones.
Among postmenopausal women, who make up the great majority of all new breast cancer cases, the single most significant risk factor for having elevated levels of estrogen in the blood was obesity, in this study. Although obesity has long been known to be a risk factor both for developing breast cancer and for experiencing a recurrence of a prior breast cancer, it has not been entirely clear how excess body weight actually causes breast cancer risk to increase. (Aromatase, an enzyme that is manufactured by fat cells, is known to increase the production of estrogen in overweight and obese women and men, and has long been suspected to contribute to breast cancer risk in obese women.) Perhaps the most important finding of this new report, therefore, is to confirm the long-suspected linkage between excess weight and elevated levels of estrogen in the blood. Increased estrogen levels, in turn, are known to increase a woman’s risk of developing breast cancer.
The findings of this report also indicate that, second only to obesity, regular alcohol intake and smoking were the next most significant lifestyle-related factors associated with an increased circulating level of estrogen and other sex hormones. (Both alcohol and smoking have previously, and consistently, been linked to breast cancer risk. Indeed, as I discuss in A Cancer Prevention Guide for the Human Race, women who consume 2 or more alcoholic beverages per day have been shown, by multiple studies, to experience a significant increase in breast cancer risk, as well as an increased risk of several other cancers.)
While some breast cancer risk factors (such as gender, age, and family history) cannot be changed, this new report, and the research studies which it analyzes, confirms that women can significantly reduce their risk of developing breast cancer by making evidence-based changes in their lifestyle and diet. When it comes to cancer, an ounce of cancer prevention really is worth a ton of cancer treatment or cancer cure.
For a comprehensive guide to living an evidence-based cancer prevention lifestyle, order your copy of my new book, A Cancer Prevention Guide for the Human Race. For the price of a cheeseburger, fries, and a shake, you can purchase this landmark new book, in both paperback and e-book formats, and begin living an evidence-based cancer prevention lifestyle today!