Bone health is a relevant issue for women, regardless of age, health status, physique and level of activity—and a well-known feminizing hormone called estrogen has a unique role in it.
Studying the scaffolding
To understand bone health, it would be helpful to know just what makes up our skeletons. Like buildings under construction, bones also have their own internal scaffolding, made up of collagen that has been mineralized—or to use our construction analogy, cemented—with calcium and phosphate.
Once formed, bones don’t stay unchanged. In fact, they are regularly broken down or resorbed by cells called osteoclasts, and formed again by bone-depositing osteoblasts. This allows its adaptation to stress loads, and the replacement of old, brittle bones.
The delicate balance between bone degradation and formation is influenced by hormones, including estrogen. Estrogen tips the scale in favor of bone growth, which explains the surge in height and bone mass during puberty. The reverse is also true: At menopause, when the ovaries stop producing estrogen, there is a shift towards faster bone degradation and slower bone formation.
The female athlete triad
Sports often requires players to maintain a lean physique, so athletes are kept on low-calorie diets. Coupled with enormous energy expenditure during training, inadequate calorie intake stresses the body to a point that the hormonal triggers for estrogen production are hindered. With such low levels of estrogen, females cannot menstruate. Since estrogen cues for bone growth, lack of this hormone leads to brittle bones. The combination of eating disorder, no menstruation and low bone density is known as “female athlete triad.”
To compound the problem, the skeletons of these athletes are stressed or exposed to various forces like shearing, compression and torsion, making them easy candidates for fractures. Quite often, their muscles are also fatigued due to excessive training and can no longer serve as the soft tissue support system of long bones.
Osteoporosis and fractures
In Current Medical Diagnosis and Treatment, osteoporosis is defined as “a decrease in the amount of bone present to a level below which it is capable of maintaining the structural integrity of the skeleton.” Its main cause, as in women who have reached menopause, is estrogen deficiency. The World Health Organization also lists other risk factors such as smoking, excessive alcohol intake, parental history of hip fracture, and intake of corticosteroids.
The main problem with osteoporosis is that it’s only when brittle bones develop fractures that some patients find out about their low bone mineral density—making vigilance and prevention crucial.
For any female at any age, it’s prudent to invest in bone health. Load up on calcium. Female adolescents require 1,000 mg of calcium per day; beyond age 20, women can get by with 750 to 800 mg a day. Milk packs approximately 1,150 mg of calcium per liter—two glasses of milk a day should suffice.
You can also get your daily dose through bread and other dairy products except butter and cream. Mustasa, malunggay, pechay, saluyot, and gabi leaves are excellent sources; cook them before eating to release the calcium. Sardines, salmon and oysters contain more calcium than red meats. Don’t take your iron tablets with calcium-rich foods; these two minerals compete for absorption. Drink tea and coffee in between meals, since these inhibit calcium absorption.
For more on bone health for ladies, grab a copy of the October issue of HealthToday, out now in bookstores and newsstands.