HEALTH AND FITNESS: Exercise and breast cancer
Many local and national organizations are promoting breast cancer awareness, sharing information about the disease and celebrating survivors as a part of Breast Cancer Awareness month. These are all worthy goals that deserve our full attention and support.
Each year more than 200,000 women are diagnosed with breast cancer, and 40,000 die from this disease. Between 20 to 30 percent of cases occur in women who have a family history of breast cancer. A woman with a first-degree relative (mother, sister or daughter) who has had breast cancer has nearly twice the risk of being diagnosed herself. However, most women who are diagnosed with breast cancer have no family history, so there are other factors that can increase or decrease the risk. Among these is regular exercise.
Regular activity and exercise can lower breast cancer risk by as much as 30 percent, according to a recent study of more than 3,000 women. The intensity of the activity didnít seem to matter, so participation in light activity such as housework and gardening was as effective as walking. What did matter was the amount of time spent being active. Women who reported even low amounts of activity showed a 6 percent reduction in breast cancer risk, but the greatest benefits was seem in women who were active for more than 10 hours per week.
Women who exercise regularly also have a lower chance of recurrence of breast cancer. As many as 1 in 5 of breast cancer survivors experience a recurrence within 10 years. Even relatively low levels of exercise can reduce the risk by 25 percent, but women who are very active have a greater reduction in the recurrence of breast cancer. The amount of exercise needed to realize these benefits is equivalent to 45 to 60 minutes of brisk walking five days per week.
Exercise is effective for reducing breast cancer risk because it lowers levels of the hormone estrogen. This is important because estrogen is linked with the majority of breast cancers and is especially relevant for women with estrogen receptor-positive cancers.
Exercise can also reduce the risk of breast cancer by helping with weight control. Excess body fat increases levels of estrogen, resulting in a higher risk of breast cancer diagnosis and recurrence. Regular physical activity is essential for losing weight and keeping it off. Exercise can also help reduce the increased risk of breast cancer that comes with weight gain, something that is common as women get older.
Women who have been active their whole lives have the lowest risk of breast cancer, but it is never too late to start. Women who exercise also tend to handle breast cancer treatment better than women who arenít active. In fact, post-cancer exercise programs are becoming more common as a way to help women recover from cancer treatment and prevent recurrence.
Other lifestyle changes that can reduce the risk of breast cancer include maintaining a healthy body weight, consuming alcohol in moderation, not smoking and eating a diet rich in fruits and vegetables. The good news is that these changes also reduce the risk of other cancers, cardiovascular disease and most other chronic diseases.
Brian Parr, Ph.D., is an associate professor in the Department of Exercise and Sports Science at USC Aiken where he teaches courses in exercise physiology, nutrition and health behavior. He is a member of the American College of Sports Medicine and is an ACSM certified clinical exercise specialist; his research focuses on physical activity in weight management and the impact of the environment on activity and diet. Parr lives in Aiken with his wife, Laura, and sons Noah, Owen and Simon.