FRIDAY, Sept. 14, 2001 (HealthDayNews) -- So, you thought the only thing sweeping accomplished was a cleaner kitchen floor? Guess again. A new study says doing housework may decrease your risk of breast cancer in the post-menopausal years.
But before you swap that high powered CEO job for pots, pans, vacuums and brooms, note that the study also found occupational activity is good for you, as well.
"The main result of the study is that total lifetime activity is important for reducing breast cancer risks," says lead study author Christine Friedenreich, research scientist on the Alberta Cancer Board, the Canadian group that did the research.
While the idea that physical activity can affect breast cancer is not new, the study is the first to document specific types of regular activity that can provide at least as many health benefits as a vigorous exercise program.
Indeed, Friedenreich says the study shows that, at least for post-menopausal women, housework beats recreational fun, including all exercise and sport activities, as a way to reduce breast-cancer risks. She says one reason may be that women simply do more housework than they do Jane-Fonda-style bumps and grinds.
Because "women do a lot of their activity in a day around their home and less of it through organized exercise or sports activity," Friedenreich says the study result may be "a reflection of where they were actually obtaining most of their activity."
Breast-cancer expert Dr. Bonnie Reichman of Weill Cornell Medical College, says, "I wouldn't say that exercise, in and of itself, is not as helpful in reducing risks as vacuuming; I just think this particular group of women probably didn't do a lot of formal fitness activities, which is what may have swayed the results."
Work outside the home also yielded results worth noting, Friedenreich says.
"We recorded all jobs, whether paid or volunteer work, and we included walking and bicycling to work," and the study shows this group also experienced a reduction in breast cancer risks, Friedenreich says.
While researchers aren't certain how activity reduces cancer risks, Friedenreich cites several theories.
"There are several hypothesized biologic mechanisms whereby physical activity may influence breast cancer risks [including] an influence on sex and metabolic hormonal levels, on obesity or on immune function," says Friedenreich.
However, she says there is still little direct evidence for these mechanisms, and more research is needed.
Reichman says, "What we do know right now is that breast cancer risks go down when physical activity goes up, and that gives women the opportunity to control at least one risk factor for a major disease, and that is significant."
The study involved more than 2,000 women, including 1,233 diagnosed with breast cancer and 1,237 in a healthy control group. The study population was further divided into two groups -- pre- and post-menopausal.
All the women were interviewed on a wide range of subjects. Medical questions included menstrual and reproductive history, hormone use, mammography history and personal history of breast disease. Lifestyle questions focused on diet, alcohol consumption, smoking and lifetime physical activity.
Physical activity was then further divided into three categories: occupational, recreational and household. The frequency and duration of the activities were assessed by recording the number of years, months-per-year, weeks-per-month, days-per-week and hours-per-day for each activity.
Activities also were rated by intensity, including sedentary (for occupational activities only), light, moderate or heavy. The definition of occupational activity included all work outside the home, including volunteer work and walking or bicycling to work; recreational activity included all sports and exercise activities; household activity included all housekeeping work.
The result: A 30 percent risk reduction in breast cancer for post-menopausal women with the highest rate of total lifetime activity, and that the decrease was directly related to both occupational and household activity. No activity-related decrease risk was seen in pre-menopausal women.
"What is positive about our research is that there is now even better evidence that being physically active can reduce our risk of breast cancer," says Friedenreich. The findings appear in the August issue of the American Journal of Epidemiology.
Reichman says, "It's another piece of data in support of what we already know -- exercise is good for you."
What To Do
For an overview of the links between breast cancer and exercise, visit the Women's Sports Foundation.
Check the American Cancer Foundation to learn more about cancer prevention strategies.
To find the diet and activity factors that affect the risks of all types of cancers, click here.
