One quarter of all women will break a bone as a result of osteoporosis. Experts say the answer lies in building a calcium “bank” while we are young. Imagine turning over in bed and breaking an arm; or sneezing and breaking several ribs; or leaning against a wall and cracking your spine. Such spontaneous fractures, caused by a deficiency of mineralized bone, are a consequence of osteoporosis.
Osteoporosis is a disease that thins the bones and can reduce life expectancy in 20 percent of sufferers. Bones provide scaffolding for muscles and tendons and protect vital organs. When they break, the consequences can be extreme and costly.
As the number of elderly women in the community increases, so does the incidence of osteoporosis. It is a disease that affects 25 percent of women and seven percent of men. A precise costing has never been undertaken, but osteoporosis is estimated to cost the community between $250-$500 million a year.
Now it has become the focus of new research based on the young. A study has just begun in Melbourne to find links between the diet, exercise and bone density of 90 young girls. Conducted by the Austin Hospital’s bone density unit and Melbourne University’s department of medicine, the three-year study will compare two groups of girls. Supported by the Dairy Research Council, the study will compare 30 elite gymnasts, aged eight to 16 years, from the Victorian Institute of Sport and 60 girls, aged six to 10, from a girls’ grammar school.
Ms. Shona Bass, who is conducting the study, said the gymnasts were chosen because of their homogeneity—the fact they have similar diets and the same 30 hour-a-week exercise program. The comparison group had varied diets and lifestyles. The early studies already indicate that the pre-pubescent girls among the gymnasts appear to have greater bone density than sedentary children of a similar age.
Ms. Bass, who is working with Ms. Karen Inge, a dietitian with the Victorian Institute of Sport, said she was concerned that children and teenagers were exchanging dairy products for caffeine-based drinks, including tea, coffee and soft drinks. Her sentiments are echoed by Dr. Kong Wah Ng, of the metabolic bone disorder clinic at St. Vincent’s Hospital, who is experimenting with a new drug called tildronate to prevent more fractures in patients with osteoporosis.
Dr. Ng believes the prevention of osteoporosis depends on parents ensuring their children have high-calcium diets and regular exercise. He advocates that people under 20 drink three glasses of milk a day, eat more dairy products, exercise regularly and expose themselves to 15 minutes of sunlight (providing vitamin D) daily. He is concerned that all the negative publicity given to the fat content in dairy foods is influencing children to adopt imbalanced diets at an age when they need a high calcium intake to build their bones.
For years it was considered a natural sign of growing old: a woman with a hump back and walking stick. It was not until the 1940s that osteoporosis was defined as a bone mass deficiency that affected women as they entered menopause and stopped producing estrogen—a key hormone that assists calcium absorption. Women can lose half their bone mass in the first six years following menopause. One in three women who make it to age 90 will fracture a hip. Vertebral fractures can cause severe deformity, chronic pain and disability, and loss of independence. In rare cases, respiratory obstruction due to collapse of the spine can cause death. One in six ageing men also contract some form of osteoporosis and come to rely on calcium supplements and special exercise.
Until recently, treatment for women has centered on hormone replacement therapy, calcium supplements (up to 1000 milligrams a day) and weight- bearing exercises. The effects of oral drugs to prevent further bone loss in middle age are still being researched in Australia and such drugs are not yet available. Doctors are divided about the benefits of calcium supplements in middle age, many arguing that an adequate daily diet that provides around 700 milligrams of calcium will suffice. Research has also shown mixed results on the benefits of exercise in preventing bone loss in older people.