The 'Real Skinny' On Breast Cancer - What Women CAN Do
Author: Virginia M. Herrmann, M.D.
A number of factors increase a woman’s risk of developing breast cancer. Last year in CH2, I spoke about risk factors not in our control, to include: Early age at first menstruation, late age at menopause, never having children, or having a first child after age 35, a prior history of breast cancer, family history of breast cancer, and/or a genetic mutation or abnormality associated with an increased risk of developing breast cancer.
Although we have no control over most of these, recognizing the risk factors allows a breast surgeon to follow women more closely and offer strategy to reduce the risk.
Risk factors women can control include the following:
WEIGHT GAIN AND BODY MASS INDEX
Over the last two decades, the incidence of breast cancer in the United States and Europe has increased; it is significantly higher in well-developed countries than in developing nations. A number of risk factors associated with a “western lifestyle” have been studied, to include diet, food intake, body weight, and age at menstruation, which is earlier in well-developed, industrialized countries.
Surprisingly, breast cancer risk has not been definitively linked to diets high in animal fat or rich in dairy products. In fact, diets low in animal fat and high in fruits and vegetables, while good for your heart, do not lower the risk of breast cancer. So how do we explain the increased incidence of breast cancer in well-developed countries? One answer is breast cancer is associated with an increase in weight, or body mass index.
In the United States, over two-thirds of all adults are overweight. This is important to our discussion since breast cancer risk is associated with body weight, body mass index, and weight to hip ratio. Body Mass Index (BMI) is defined as a person’s weight in kilograms, divided by the square of height in meters. You can calculate your BMI by accessing the formula on many Internet sites. Normal BMI for women is between 18.5 and 24.9. Anything over 25 is considered overweight, and over 30 is obese. The risk of developing breast cancer, especially in post-menopausal women, is higher if the BMI is above 25 and significantly higher if over 30.
Interestingly, BMI and body weight affect women differently depending on their menopausal status. Women who are pre-menopausal and obese have a lower risk of developing breast cancer than women of normal weight. However, if a woman gains weight after age 18, and carries this weight with her until she is post-menopausal, her risk of breast cancer is increased. Studies show being overweight after menopause increases the risk of breast cancer by as much as 30 to 60 percent. Weight gain after menopause is also associated with an increase in breast cancer, independent of the BMI. Additionally, the risk of dying from breast cancer is also higher in post-menopausal women who are obese. In summary, it is likely the total amount of food we eat is more important than what we eat.
The good news is that women who lose weight after menopause can decrease their risk of breast cancer. Researchers have shown that even losing 4 to 10 pounds can decrease a woman’s risk by as much as 20 percent.
Women who gain weight around their waist have a slightly greater risk of breast cancer compared to women who gain weight in their hips and thighs. Weight to hip ratio looks at a woman’s weight divided by her hip circumference. As this value increases, so does the risk of breast cancer. When women gain weight after menopause, levels of other hormones related to insulin change, and these hormonal changes have been associated with an increase in breast cancer.
WOMEN CAN REDUCE THEIR RISK OF BREAST CANCER BY:
- Maintaining a normal BMI (18.5-25)
- Avoiding weight gain, especially after menopause
- Trying to shed even a few pounds if needed.
EXERCISE AND BREAST CANCER RISK
There is increasing evidence that exercise may decrease the risk of breast and other cancers, independent of body mass index or body weight. Exercise changes the “Metabolic Syndrome,” defined as the presence of obesity, hypertension (high blood pressure), glucose intolerance (or early diabetes), high triglycerides, and low levels of HDL cholesterol (the “good cholesterol”). This syndrome is increasingly diagnosed in U.S. women and causes an increased risk of breast cancer. A low HDL presents a significant increased risk. This risk can be reduced by weight loss, but sometimes weight loss is not enough.
Regular exercise or physical activity helps as it reduces insulin levels in the body which, in turn, lowers the risk of breast cancer. Even brisk walking 30 minutes a week can reduce a woman’s insulin level.
The data regarding exercise and breast cancer is even more impressive in women who have already been diagnosed. The Journal of the American Medical Association published a study of over 3,000 women who had been diagnosed with breast cancer. The women who engaged in a few hours of walking or other exercise each week were less likely to die of breast cancer when compared to women who had engaged in less than one hour of exercise or physical activity per week. Beneficial exercise included walking, hiking, running, jogging, cycling, swimming, tennis, aerobics, squash, racquetball, or a rowing machine. The women who exercised also reported better mood, improved body image, and higher self-esteem.
In summary, although American women are busy caring for others, we can and should reduce our risk of breast cancer by regular exercise.
Since World War II, there has been a notable increase in the number of women who drink as well as the amount of alcohol they consume. While moderate alcohol intake in men has been shown to decrease the risk of heart attack, this data may not apply to women. Even moderate alcohol intake in women may have more risk than benefit. Women metabolize alcohol differently than men do and are more susceptible to cirrhosis as well as breast cancer.
Women are smart consumers in every aspect of their lives, and should be smart when it comes to nutrition, and in particular, alcohol. Women should keep in mind the following:
- Even moderate alcohol consumption (more than 4 to 7 drinks per week) in women has been associated with an increased risk of breast cancer.
- The risk of breast cancer increases in direct proportion to the amount of alcohol consumed, regardless of the type of drink (e.g. beer, wine or mixed drink).
- This increased risk is seen primarily in women who are post-menopausal.
- The risk of breast cancer is increased further in women who take hormone replacement therapy and drink alcohol.
It is certainly reasonable for women to enjoy a glass of wine, or other alcoholic beverage. However, women who drink should keep in mind:
- If you drink, do so in moderation. If you have a couple of glasses on weekend evenings, try skipping a few days, or decrease your intake to one glass per evening.
- Women who drink should take a daily multivitamin. Folate has been shown to be helpful in protecting women from some of the effects of alcohol on cancer risk. Most daily multivitamins contain sufficient folate (300-400 ug). However, taking more folate than the recommended 300-400 ug is of no benefit.
In summary, every woman should try to maintain a healthy weight and BMI. If you have gained weight, especially after menopause, work on trying to lose a few pounds every month until you reach your goal. Find an enjoyable physical activity that suits you, and your schedule.
Dr. Herrmann is Professor of Surgery at the Medical University of South Carolina and a member of the Hollings Cancer Center Comprehensive Breast Program. She serves as Medical Director of the Hilton Head Hospital Breast Health Center. The Hilton Head Hospital Breast Health Center one of its kind in Beaufort, Jasper and Hampton County and now designated a fully accredited program by the National Accreditation Program for Breast Centers (NAPBC).
The program, administered by the American College of Surgeons, awarded the Hilton Head Hospital Breast Health Center, a three-year, full accreditation in September 2011. Accreditation by the program ensures that patients will have access to:
• Comprehensive care, including a full range of services right here at home.
• Multidisciplinary team approach to coordinate the best treatment options
• Information about ongoing clinical trials and new treatment options
For more information about the Hilton Head Hospital Breast Health Center call 843-682-7377.