Bones are the framework for your body. Bone is living tissue
that changes constantly, with bits of old bone being removed and replaced by
new bone. You can think of bone as a bank account, where you make “deposits”
and “withdrawals” of bone tissue.
During childhood and adolescence, much more bone is deposited
than withdrawn, so the skeleton grows in both size and density. Up to 90
percent of peak bone mass is acquired by age 18 in girls and age 20 in boys,
which makes youth the best time to “invest” in your bone health.
For years, we've thought we understood osteoporosis: it's a disease in
which the bones become more and more fragile as they lose density, usually due
to aging, menopause, and other factors like lack of calcium and
vitamin D in the diet.
But today, advances in research are shedding new light on osteoporosis,
which is predicted to affect as many as half of all Americans over age 50 by
the year 2020. From diagnosis to prevention to osteoporosis treatment, new research is turning our old
The amount of bone tissue in the skeleton, known as bone mass,
can keep growing until around age 30. At that point, bones have reached their
maximum strength and density, known as peak bone mass. In women, there tends to
be minimal change in total bone mass between age 30 and menopause. But in the
first few years after menopause, most women experience rapid bone loss, a
“withdrawal” from the bone bank account, which then slows but continues
throughout the postmenopausal years. This loss of bone mass can lead to
osteoporosis. Given the knowledge that high peak bone density reduces
osteoporosis risk later in life, it makes sense to pay more attention to those
factors that affect peak bone mass.
Factors Affecting Peak Bone Mass
Peak bone mass is influenced by a variety of genetic and
environmental factors. It has been suggested that genetic factors (those you
were born with and cannot change, like your gender and race) may account for up
to 75 percent of bone mass, while environmental factors (like your diet and
exercise habits) account for the remaining 25 percent.
Gender: Peak bone mass tends to be higher in
men than in women. Before puberty, boys and girls acquire bone mass at similar
rates. After puberty, however, men tend to acquire greater bone mass than
Race: For reasons still not known, African
American females tend to achieve higher peak bone mass than Caucasian females.
These differences in bone density are seen even during childhood and