August 19, 2011
Dear Mayo Clinic:
I am a two-year breast cancer survivor. What lifestyle choices will actually make a difference as far as preventing a recurrence?
As a breast cancer survivor, you can take steps to help reduce the risk of recurrence. They include maintaining a healthy weight, exercising regularly and limiting the amount of alcohol you drink. Not only will these lifestyle changes decrease the chances that breast cancer will return, they can lower your risk of other serious illnesses, too.
Among the most important steps is maintaining a healthy weight, especially in the years following menopause. Research suggests that fat (adipose) tissue is a source of estrogen. Many breast cancers are hormone sensitive and can grow faster in the presence of estrogen and progesterone. So, carrying extra fat tissue may increase the possibility that breast cancer will develop, particularly in women with a history of breast cancer.
Staying at a healthy weight, or losing weight if necessary, reduces fat tissue, decreasing the amount of estrogen in the body and in turn lowering your risk of an estrogen-sensitive cancer. Research estimates are that a healthy weight can reduce your breast cancer risk by about 26 percent. Although there are no specific dietary guidelines for breast cancer survivors, a well-balanced diet rich in fruits, grains and vegetables and low in fats and sugars can help maintain a healthy weight.
A formula called the body mass index (BMI), which compares weight to height, can help determine if you are in a healthy weight range. BMI is calculated by dividing weight in kilograms by height in meters squared. For most people, a BMI between 18.5 and 24.9 is considered normal.
Closely linked to staying at a healthy weight is exercising regularly. Exercise has been shown to decrease estrogen levels, lower insulin levels and help boost the immune system. There is good evidence that starting to exercise regularly before menopause has long-term benefits against breast cancer. If exercise isn't part of your daily routine, starting slow is fine. Aim for at least 30 minutes of exercise three times a week. Remember, you don't have to train for a marathon. Brisk walking, bicycle riding and swimming are good ways to get the exercise your body needs.
The benefits that come with staying at a healthy weight and exercising regularly extend far beyond reducing your breast cancer risk. They can also help prevent colon cancer and other types of gastrointestinal cancers, as well as gynecologic cancers such as endometrial cancer. Being overweight is a risk factor for these types of cancer.
In addition, weight loss and exercise have clearly been shown to help prevent heart disease — the number one cause of death for women in the U.S. Finally, regular exercise is known to help prevent bone loss that can lead to osteoporosis. That's particularly significant for women who are in menopause and critical for those who are taking anti-estrogen therapies to reduce breast cancer recurrence risk, because these therapies can speed the development of osteoporosis.
The other important change you can make is limiting how much alcohol you drink. Research suggests that the more alcohol consumed, the greater the risk of developing breast cancer. The general recommendation is that women limit their alcohol intake on average to no more than one alcoholic beverage a day (8 ounces of wine, 16 ounces of beer, or 1.5 ounces of hard liquor).
By following these lifestyle recommendations, you can play a key part in decreasing your risk of recurrent breast cancer. For details on a weight-loss or exercise program that's right for you, or for strategies on how to limit your alcohol intake, talk to your doctor.
— Sandhya Pruthi, M.D., Breast Diagnostic Clinic, Mayo Clinic, Rochester, Minn.