Exercise
Plus Calcium Helps Keep Bones Strong
Bone
Density May Improve For Some
Women
who have stopped taking hormone replacement therapy (HRT) often worry
about losing the protective effect that estrogen had on their bone density.
But
a new study reported in the medical journal Osteoporosis International
suggests that performing regular weight-bearing and resistance exercise,
and consuming calcium in foods and supplementation, can help maintain
bone density, especially in the hip.
Researchers looked at the effect of exercise and calcium
in two groups of women, those already on HRT and those who were not,
says study author Dr. Timothy Lohman, a researcher at the University
of Arizona.
The effects on bone were better with HRT, especially
in the spine area, Dr. Lohman concedes, but adds, "In the hip area,
it looks good just with exercise and calcium."
The study reported
by Dr. Lohman is known as The Bone, Estrogen and Strength Training
(BEST) study, and is supported by the National Institutes
of Health (NIH).
Women
Look for Alternatives to HRT
When the Women's
Health Initiative was halted last year after unacceptably increased
risks of breast cancer and heart attack were found among women on HRT
compared to those not on the regimen, many women decided to discontinue
the daily treatment and many others opted not to start it.
But one potential downside was losing the known protective
effect estrogen has on maintaining bone density and decreasing the risk
of osteoporosis, the gradual loss of bone density that can lead to fractures
of the hip, spine, and wrist.
In the most recent evaluation, researchers looked at
159 women who were on HRT and 161 who had not used it, dividing those
two groups into an exercising group or a non-exercising group, for a
total of four groups.
The exercise regimen, performed three days each week,
included 20 to 25 minutes of resistance training (two sets of six to
eight repetitions) and six exercises (back extension, leg press, squats,
the lateral pulldown, dumbbell press, and seated row).
Women also performed seven to 10 minutes of cardiovascular
weight-bearing activity, such as jumping rope, jogging, or skipping,
during each session.
All women took a total of 800 milligrams of calcium
citrate daily, with two pills spaced at least four hours apart.
Those who took HRT, calcium, and who exercised increased
their bone density in more body sites, increasing it by 1 percent to
2 percent in the hip and spine, Dr. Lohman says.
In those women who exercised and took calcium but did
not take HRT, bone density in the hip increased about 1 percent, the
study reports.
"HRT was critical for improving spine bone density,
but not hip density," says Linda Houtkooper, another member of
the research team. And, she stresses, it was the combination of both
types of exercise and getting calcium from both food and supplements
that appeared critical.
As a woman ages, just maintaining the bone mass she
has can be good news.
Maintaining
Bone Density a Must
"If a woman
in her 50s can just maintain her bone mass, she goes a long way toward
warding off osteoporosis," Dr. Lohman says. "Exercise helps
you whether you are on HRT or not."
The study "confirms what we have known," says
Dr. Robert P. Heaney, an osteoporosis researcher at Creighton University
in Omaha. "It shows that if you exercise and are given adequate
calcium and are on hormones, you will preserve bone."
He views the preservation of bone as a "three-legged
stool. One is hormones, one is nutrition, one is exercise," he
says.
"I think hormones are still important," Dr.
Heaney adds, although he recommends that estrogen be given by patch
rather than orally to preserve bone after menopause.
Women who use weight-training must progress to heavier
weights to achieve the benefit, Dr. Lohman says. And he advises them
to check in first with their physician and with a physical therapist.
The physical therapist can alert women to any physical limitations and
instruct them on the proper way to do the exercises.
Dr. Lohman also recommends that all women get a baseline
bone density test in their 40s or 50s, then repeat it annually.
Depending on age,
a daily calcium intake of 1,000 mg to 1,300 mg is recommended, according
to the National Osteoporosis Foundation. If women have
trouble taking in that much from calcium-rich foods such as dairy products,
supplements are recommended.
Always consult your physician for a diagnosis.
Online
Resources
Centers
for Disease Control and Prevention (CDC)
HealthierUS.Gov
National
Institute of Arthritis and Musculoskeletal and Skin Diseases
National
Institutes of Health (NIH)
National
Osteoporosis Foundation
National
Women's Health Information Center
Osteoporosis
and Related Bone Diseases - National Resource Center
Office
of Research on Women's Health |
