February 01, 2012

Weight Loss and Exercise May Improve Your Odds Against Developing Breast Cancer

SIOUX FALLS (Feb. 1, 2012) – If exercise and weight loss are your goals in 2012, you won’t only improve your heart health, or look better in your favorite jeans. You will improve your odds against developing breast cancer and other types of cancer.

“We’ve known for a long time that obesity lowers life expectancy by contributing to diabetes, high blood pressure, heart disease and stroke,” said Dr. Amy Krie, oncologist with Avera Medical Group Oncology & Hematology, who specializes in treating breast cancer. “More recently, ties between obesity and cancer have become evident.” Dr. Krie says there is solid research tying obesity with post-menopausal breast cancer, endometrial or uterine cancer, and other cancers, including those of the kidney, colon, esophagus, ovary and pancreas.

Obesity is an epidemic across the United States that is only getting worse. Over one-third of the adult population in the U.S. is considered to be obese – another one-third of adults are overweight, but not yet obese. Obesity is measured by body mass index. You can calculate your own body mass index using this online tool.

The tie between obesity and breast cancer is particularly striking, Dr. Krie says. Research shows:

• Obese women are 30 to 50 percent more likely to develop breast cancer than women of a healthy weight.
• Women who walk 30 minutes per day lower their rate of breast cancer by 20 percent.
• Women who gain 20 to 30 pounds after age 18 are 40 percent more likely to develop breast cancer than those women who stay within five pounds. Women who gain 70 pounds double their risk of breast cancer.

Research also shows that breast cancer survivors who do not gain weight after their diagnosis and maintain a healthy weight are less likely to have a recurrence of breast cancer.

“Certainly, the connection between obesity and cancer is one we’re still unraveling,” Dr. Krie said. The reasons why obesity is linked to breast cancer are complex. Simply put, being overweight means you have higher levels of hormones in your bloodstream, because fat cells produce estrogen. Also, being overweight can cause insulin resistance, leading to higher levels of insulin in the bloodstream. This causes inflammation and also prevents cancer cells from dying.

“In order for a cancer cell to grow, it needs to have the right microenvironment. If your microenvironment is healthy, it is harder for cancer cells to set up shop,” Dr. Krie said.

Exercise is one key to cancer prevention. “Exercise lowers estrogen and insulin levels, decreases inflammation, relieves stress and improves your immune system,” Dr. Krie said. “Exercise helps you set up a very healthy environment so that tumors can’t grow.”

“We also recommend a diet that’s lower in carbohydrates, and one that’s higher in fish and low-fat meats, vegetables and especially leafy green vegetables, and whole grains. An ideal diet would be more like an Asian or Mediterranean diet,” Dr. Krie said.

A research study is underway at Avera to determine if a diet that is adequate in protein and lower in carbohydrate has a positive impact on breast cancer recurrence. Other current research is studying whether drugs commonly used to control diabetes and high blood pressure can also prevent cancer recurrence.

“Statistics show that one in eight women will experience breast cancer within their lifetime. We all want to improve our odds, and there are lifestyle changes we can all make to reduce our risk of cancer,” Dr. Krie said.

To learn more about breast cancer prevention and early detection, go to www.AveraThinkPink.org