Diet and lifestyle changes may reduce the risks
By Heather Hatfield
WebMD Weight Loss Clinic - Feature
Reviewed By Cynthia Dennison Haines, MD
Breast cancer is the disease most feared by many women, even though both heart disease and lung cancer kill more women in the U.S. One reason may be that it's still not clear exactly what causes breast cancer. So is there anything you can do to help prevent it?
While many of the factors that influence whether you're at risk for breast cancer are outside your control, experts say there are things you can do to improve the odds. Just as diet, weight, and exercise have a big influence on your overall health, they may make a difference in your breast cancer risks as well.
Many studies about diet and health do little more than confuse you. But when it comes to cancer, the advice is consistent: A healthy diet and active lifestyle can help improve your chances.
By following the WebMD Weight Loss Clinic's advice, you will not only lose weight, but you will also boost your health and help prevent chronic diseases.
When choosing foods on your individualized eating plan, pick a rainbow of colorful fruits and vegetables, along with low-fat dairy, whole grains, heart-healthy salmon, and other lean protein. Couple these super-nutritious foods with regular physical activity to wage your own personal war against cancer.
"There are a lot of factors that contribute to breast cancer risk that you have no control over: what age you started your period, what age you had children, what age you began menopause, and family history of breast cancer," says Colleen Doyle, MS, a registered dietitian and nutrition and physical activity director for the American Cancer Society. (Having your first child after age 30 or never having children puts you at higher risk; so do getting your first period before age 12, starting menopause after age 50, or having family members who got the disease.)
"You can't do anything about these risk factors,'' says Doyle, "but you can do something about your diet and weight, and you can do something about your level of physical activity."
A Weighty Matter
Research has consistently shown a link between obesity and breast cancer in postmenopausal women, experts say. Consider a recent study of more then 62,000 women, published in Cancer Epidemiology, Biomarkers & Prevention.
"For women who gained 21-30 pounds throughout their adult lifetime, meaning since the age of 18, they were at a 40% increased risk for breast cancer, post-menopause," says Heather Spencer Feigelson, PhD, MPH, co-author of the study. "Women who gained 70 pounds in adult life were at twice the risk, compared to women who stayed within five pounds of their weight." (None of the women in the study were taking hormone replacement therapy.)
Why the increased risk with the increase in weight?
The more fat a woman has, the more estrogen she will produce, explains Spencer Feigelson, who is also a senior epidemiologist with the American Cancer Society. After menopause, the more estrogen a woman's body produces, the higher her risk of breast cancer. So having lots of body fat increases estrogen levels, and therefore, breast cancer risk.
The Nutrition Connection
Aside from keeping calories at a reasonable level to avoid weight gain, what can you eat to help ward off breast cancer?
As complex as nutrition is, it boils down to simple rules that have a ripple effect across your entire body, explains Susan Moores, RD, a spokeswoman for the American Dietetic Association.
"Everything that I tell you now is very much the same as that you would hear for any other health condition," Moores says. "If you are doing some or all of these things, it might lower your risk for breast cancer, but it can also do great things for your heart, osteoporosis, and other cancers."
As for specific foods, "there is interesting research around the possible beneficial impact of omega-3 fatty acids, which are found in fish," says Moores. Fish high in omega-3 fatty acids include coldwater fish such as salmon, tuna, herring, mackerel, sturgeon, and anchovies. Walnuts and flaxseed are plant-based sources of omega-3.
Preliminary studies have also indicated that "vitamin D and calcium ... particularly in low-fat dairy food, could reduce tissue changes in the breast," Moores says. And women who have changes in breast tissue are thought to be at a greater risk for breast cancer.
Again, says Moores, vitamin D and calcium go beyond breast cancer -- they also help prevent osteoporosis.
"Talk about a population that needs both of these, for more reason than one," says Moores. "Ninety to 95% of girls and women aren't getting enough calcium. And for women over 19, just about 80% are not getting enough vitamin D. So these are sorely lacking in many women's diets."
And then there are fruits and vegetables. "The more the better," says Moores. "Especially those really colorful fruits and veggies. ... Pull in as much color as possible and get those lycopenes [found in red produce like tomatoes] and beta-carotenes [found in orange produce like carrots]."
As much as we love those morning cups of coffee, they might not be helpful when it comes to improving the odds.
"Too much caffeine isn't linked directly with breast cancer, but it is linked with a change in breast tissue," says Moores. "Women that have changes in breast tissue are at a greater risk for breast cancer. Now, that's a huge leap, but it does seem that in high amounts, 4-5-plus caffeinated beverages a day, breast tissue could be altered, and that possibly could increase your risk for breast cancer."
Your evening cocktails could also increase your risk.
"Women who have too much alcohol are at a higher risk for breast cancer," Moores tells WebMD.
A 2003 study in the Journal of the National Cancer Institute showed that women aged 49 to 54 may be most at risk from alcohol. Researchers found that one to two drinks a day in these women increased levels of the hormone leptin by 24%. Leptin has been linked to an increased breast cancer risk.
The American Cancer Society recommends that women have no more than one alcoholic drink a day -- one drink being a five ounce glass of wine, one 12 ounce beer, or one ounce of liquor.
Exercise, of Course
As with most issues related to your health, exercise plays a role in breast cancer risks. And it's not just because working out helps keep your weight down.
"There is convincing evidence that increasing physical activity reduces risk of breast cancer, not only because of weight control but also by helping to reduce circulating hormones that are associated with breast cancer -- primarily estrogen and insulin," says Doyle.
But to get these benefits, you'll need to do more than take a stroll in the park. The exercise you should aim for is aggressive.
"The overall recommendation for physical activity is at least 30 minutes, five or more days a week," says Doyle. "For breast cancer, it's even more vigorous -- 45 minutes of moderate or vigorous exercise five or more days a week."
A Healthy Lifestyle
Of course, even if you do all of these things, there's no guarantee you won't get breast cancer. The good news, says Doyle, is that making healthy lifestyle changes will benefit you in countless other ways.
"The message we are trying to get across is that, hey, the things we are saying for breast cancer will help with diabetes, heart disease, and other conditions, as well: Eat a healthy, well-balanced diet, maintain a healthy weight, and exercise regularly."
Originally published Oct. 4, 2004.
Medically Updated Sept. 16, 2005.
SOURCES: Cancer Epidemiology, Biomarkers & Prevention. February 2004. Colleen Doyle, MS, RD, nutrition and physical activity director, American Cancer Society, Atlanta. Susan Moores, RD, spokeswoman, American Dietetic Association, St. Paul, Minn. Heather Spencer Feigelson, PhD, MPH, senior epidemiologist, American Cancer Society, Atlanta. WebMD Medical News: "Alcohol May Increase Breast Cancer Risk."
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