Can Walking Ward Off Bone Loss?
Study Shows Walking Builds Bone Mass in Men Getting Prostate Cancer Treatment
Oct. 29, 2007 (Los Angeles) -- Brisk walking may reverse the severe bone
loss associated with a common prostate cancer therapy, curbing the risk of
fractures and osteoporosis, researchers report.
In a small study of men undergoing androgen deprivation therapy (ADT) and
radiation for prostate cancer, strolling at a rapid pace for 30 minutes five
days a week for eight weeks built bone strength.
In contrast, men who didn't exercise lost bone mass, says researcher Paula
Chiplis, PhD, RN, a clinical instructor and senior research assistant in the
department of nursing at Johns Hopkins Hospital in Baltimore.
"With exercise, prostate cancer patients gained bone density at a time
in life when even healthy men are starting to lose bone density. This is really
exciting," Jennifer Wenzel, PhD, RN, a researcher at Johns Hopkins who also
worked on the study, tells WebMD.
The findings were reported at the American Society for Therapeutic Radiology
and Oncology's annual meeting.
Men with localized cancer that is confined to the prostate gland can be
treated with radiation therapy along with ADT. Radiation is used to kill
the cancer cells. ADT inhibits the production of hormones called androgens that
feed cancer cells, slowing tumor growth and improving the odds of survival.
But androgens also help build bone strength, so suppressing them results in
a form of "male menopause," which weakens the bones and increases the
risk of fractures and osteoporosis, Chiplis says.
Radiation is also thought to weaken bones, although the reasons are less
clear, she adds.
Brisk Walking Builds Bones
But exercise can change all that, Chiplis says. In the study, brisk walking
led to a 0.49% gain in bone mass in just eight to 10 weeks.
Men who didn't exercise lost 2.21% of their bone mass in the two-month study
period; placed in context, healthy men lose between 0.5 to 1% of their bone
mass per year, beginning in middle age, she says.
And men undergoing ADT lose 4% to 13% of their bone density annually,
Chiplis tells WebMD. "Given these benchmarks, the effect of exercise is
Exercise May Help
The findings grew out of a larger project designed to look at the effects of
exercise on fatigue in 70 men with localized prostate cancer undergoing
radiation therapy with or without ADT. Half agreed to take brisk 20 to 30
minute walks five days a week during ADT treatment.
Every two weeks, a nurse called all the participants, asking how they were
feeling. Those in the exercise group were also urged to hold back or step up
their exercises, depending on how they were feeling.
Having a nurse involved probably helped get the men motivated and out of
bed, says Phillip M. Devlin, MD, a cancer specialist at Harvard Medical School
and a spokesman for ASTRO.
He urges men with prostate cancer to get moving. While the study was small
and needs confirmation, "there is no danger in walking and it could
possibly be helpful," Devlin tells WebMD.
How fast do you need to walk to reap the benefits? "As briskly as you
can and still carry on a conversation," Chiplis says.