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| Vol. 22, No. 18 |
| October 1, 2000 |
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Research Indicates that Exercise Plays a Key Role in Reducing Breast Cancer Besides looking fit and feeling better, there is another reason why women should exercise. A recent study confirms there are benefits from exercise when it comes to breast cancer. Findings, published in the Journal of the National Cancer Institute, show that recreational physical activity actually reduces a woman's risk of breast cancer by 30 percent. This is not the first study to find an association between exercise and breast cancer, however, it is the first study that actually tracked a woman's exercise habits over a lifetime. Past research had also documented that exercise lowers a woman's risk of breast cancer, but the findings were inconsistent due to how the physical activity was assessed and the evaluation of the exercise time. In fact, an earlier study published in the New England Journal of Medicine, cites that the risk of breast cancer is only reduced if a woman exercises regularly prior to menopause. In the recent Journal of the National Cancer Institute study, researchers evaluated data collected from extensive interviews of 918 women ranging in age from 20 to 54 years of age. Information from the women was compared with data obtained from another 918 age-matched population of control subjects. Researchers evaluated the physical activity that took place when the women were 10 to 12 years of age, 13 to 15 years of age, and over their lifetimes. This information, as well as the title of the study participant's longest held job, was analyzed for any association to the risk of breast cancer. The results of the study found that the women who had been routinely physically active during the ages of 10 and 12 had a lower risk of breast cancer. Likewise, there was a reduced risk of breast cancer in women who had ever participated in some form of physical activity, in comparison to women who had never participated in any form of physical activity. The researchers also found that it was never too late to reap the benefits of exercise, in relation to reducing the risk of breast cancer. Regardless of when a woman started exercising regularly, researchers found that the risk of breast cancer was consistently reduced. When comparing body weight with exercise, and its association with breast cancer, the researchers determined that it was the lean women who faithfully exercised versus the larger women who regularly exercised that had the lower breast cancer risk. The researchers concluded that women who maintain a routine habit of exercise and a healthy weight, no matter what age they started, can actually lower their risk of breast cancer. Many researchers agree that there are physiological reasons why routine exercise may make a difference when it comes to breast cancer risk. Medical experts believe that the more estrogen surges a woman experiences, the higher her risk of breast cancer. Research from the New England Journal of Medicine study shows that strenuous, regular exercise reduces the number of ovulation cycles, which ultimately reduces the number of estrogen surges during all phases of a woman's life. For example, when a young girl is regularly active, she often postpones the start of menstruation. Adult women who exercise regularly are also more likely to ovulate less regularly, regardless of if they have regular monthly cycles. Postmenopausal women who faithfully exercise reduce their fat stores, where a version of estrogen is produced. Another reason why exercise may lower the chances of developing breast cancer, is because those who routinely exercise typically have a lower fat mass, as well as maintain a healthier diet. Research has shown that in countries where the typical diet is low in fat, the numbers of breast cancer victims are low, compared to countries where high fat diets are common. The American Cancer Society follows in this belief by listing diet as a breast cancer risk factor. The organization recommends limiting the intake of high fat foods, and maintaining a healthy weight. What is breast cancer? According to the American Cancer Society, there are several types of breast tumors. Benign, or non-cancerous, tumors are often caused by changes in the connective tissue or scar tissue formation. These changes create cysts, which are fluid filled sacs. The following is a list of some of the most common types of breast cancer: Ductal carcinoma in situ - This is the earliest stage of breast cancer. Nearly 100 percent of women who discover cancer at this stage can be cured. Lobular carcinoma in situ - Although this is not a true cancer, this condition increases a woman's risk of developing cancer. Infiltrating ductal carcinoma - Starting in a milk passage or duct, this cancer spreads to the fatty tissue of the breast and then on to other parts of the body. It is the most common type of breast cancer. Infiltrating lobular carcinoma - Starting in the milk glands of the breast, this cancer can also spread to other parts of the body. The chances of developing breast cancer Statistics from the National Cancer Institute show that as women age, their risk of breast cancer is greater. By the age of 30, the chance of a woman getting cancer is one out of 2,525. By the age of 50, the chance of a woman getting cancer is one out of 50. By the age of 80, the chance of a woman getting cancer is one out of 10. According to the American Cancer Society, breast cancer in women is the most common form of cancer. Breast cancer causes the second highest number of deaths in women, after lung cancer. The organization also estimates that in 2000, there will be 184,200 new cases of breast cancer in the U.S., and approximately 41,200 deaths.
©2006 Texas Medical Center E-Mail: tmcinfo@texmedctr.tmc.edu URL: http://www.tmc.edu/tmcnews/10_01_00/page_13.html |