Once bone density is lost, it is difficult if not
impossible to
restore.
SPEAKING AT a symposium at Stanford University in
Stanford, Calif., held in conjunction with the national conference on
advances in perinatal and pediatric nutrition, which ended on
Wednesday, Dr.
Laura Bachrach said that prevention of the bone-thinning disease
osteoporosis “must begin from the first day of life.”
“We know that peak bone mass is gained between the ages
of 20 and 30 and that this serves as a bone bank for the remainder of
your
life. The larger the bone bank account, the longer you can withstand
withdrawals before you get into trouble,” said Bachrach, who is a
professor
of pediatric endocrinology at Stanford University.
SEVERAL RISK GROUPS
According to the Washington, D.C.-based National
Osteoporosis Foundation, one in two women and one in eight men older
than 50
will have an osteoporosis-related fracture in their lifetime. Common
sites
for osteoporosis fractures are the hip, spine, wrist and ribs. One in
four
hip-fracture patients older than 50 die within one year of diagnosis.
Teens at high risk of osteopenia, a precursor of
osteoporosis, include girls who exercise too rigorously, a factor that
can
cause a decline in the production of estrogen, a hormone implicated in
healthy bones. Other high-risk youngsters include anorexics, whose
low-calorie intake weakens bones, and asthmatics treated with steroids,
a
class of drugs that can interfere with the production of a key bone
matrix
protein.
While osteoporosis is marked by
thin, fragile bones that
can easily fracture, people diagnosed with osteopenia typically have no
history of fracture despite reduced-bone density.
LIFESTYLE FACTORS
Although 60 to 80 percent of an individual’s
susceptibility to osteoporosis is genetic, Bachrach believes it’s
important
that physicians focus on the 20 to 40 percent factor that is
lifestyle-related.
For teens, “deposits” in the
bone bank should be made by
consuming a calcium quota of 1,200 to 1,500 milligrams per day, the
equivalent of four to five glasses of milk, said Bachrach. Consuming
food
and beverages with a high salt content increases the amount of calcium
lost
in urine and stools. A teen who eats a ham sandwich and pickle, for
example,
would need to drink an additional glass of milk to compensate for
calcium
loss.
Weight-bearing exercise also
strengthens bones, but it’s
important to differentiate between activities like swimming that
benefit
cardiovascular health and those that maximize bone acquisition.
Running,
jumping and gymnastics are optimal exercises for bone health, said
Bachrach.
Once bone density is lost, it is difficult if not
impossible to restore. In a study published last year in the European
Journal of Endocrinology, Japanese researchers led by Dr. Mari Hotta of
the
Tokyo Women’s Medical College found that anorexics who gained weight
did not
experience a parallel increase in bone density.
Other studies have found that prescribing estrogen to
athletes and anorexics with estrogen-deficiency had little or no effect
on
reversing osteopenia.
