Exercise Works to Protect Bones; Black Cohosh Doesn’t
JUNE 2010
Postmenopausal women can protect
their bones by exercising, but adding
black cohosh—an herbal supplement
thought to have estrogen-like effects—to
exercise confers no extra protection. That’s
the conclusion of a year-long clinical trial
involving 128 women who recently went
through menopause.
Michael Bebenek of the University of
Erlangen and colleagues randomly assigned
86 women to a vigorous exercise program
that interspersed six weeks of high-impact
aerobics and strength training with 10-week
intervals of more moderate activity such as
brisk walking and step aerobics. The rest of
the women joined a “wellness” group that
performed only less-strenuous activities
including light walking and balancing and
stretching exercise for one hour a week;
this 10-week regimen alternated with 10
weeks of no exercise at all.
Half of the exercise group also received
daily 40-milligram doses of black cohosh
(Cimicifuga racemosa), an herb touted as a
“natural” form of hormone replacement
therapy. Black cohosh has been promoted
for relief of hot flashes and other meno -
pause symptoms. Last year, an evidence
review found mixed results in seven trials of
black cohosh for menopause symptoms, but
warned that women using it should be
aware of the potential risk of liver toxicity.
Bebenek and colleagues stated that they
believe theirs is the first clinical trial to test
black cohosh for benefits on bone density.
After a year, women in the exercise
group showed no significant decline in bone
density at the spine and a slight increase in
bone mass at the hip; those in the black
cohosh subgroup saw no added benefit
from the herb. Women in the wellness
group, by comparison, saw declines in both
measures of bone density.
Researchers also measured changes in
the women’s estimated risk of suffering a
heart attack or dying of heart disease.
“Our exercise program favorably affected
bone, menopausal symptoms, lean body
mass, and, to a smaller extent, 10-year
coronary heart disease risk in early postmenopausal
women,” Bebenek and colleagues
concluded.
Supplementation with black cohosh,
they added, did not enhance these benefits.
TO LEARN MORE: Menopause, online before print;
abstract at dx.doi.org/10.1097/gme.
0b013e3181cc4a00.