Study Shows Caffeine Is Not A Risk Factor
For Bone Loss In Women

5-28-97
Hershey, Pa. -- Caffeine is not a risk factor for bone density and osteoporosis in postmenopausal women, according to a study by researchers at Penn State's College of Medicine in Hershey. The study appears in the June issue of The American Journal of Clinical Nutrition. Principal investigator Tom Lloyd, Ph.D., professor of obstetrics and gynecology at Penn State, and colleagues measured bone density of both total body and hips in 138 healthy women ages 55-70. All of the women had histories of no or minimal hormone replacement therapy and tobacco usage. Their caffeine intake was measured from their personal diet records and by chemical assessment of the caffeine in each woman's brewed caffeinated beverage. "More than 90 percent of the women's caffeine came from coffee and tea," says Lloyd.

The study, conducted in 1993-95, included similar numbers of low-, moderate- and high-caffeine consumers. Low-caffeine intake was defined as 0-2 caffeinated cups of coffee per day, moderate as 3-4 cups per day and high as 5 or more cups daily. Within these groups, women with low, moderate and high exercise patterns were recruited.

Even adjusting for age and weight, in addition to activity level, Lloyd says, "Caffeine intake was not associated with any bone mineral measurements."

High caffeine consumption has been both proposed and denied as a risk factor for decreased bone density and increased chance of osteoporotic fractures in postmenopausal women. In many of the studies, however, says Lloyd, factors affecting bone loss, like smoking, body weight, physical activity, calcium and nutrient intake and hormone replacement therapy, have not been adequately considered.

Lloyd believes that because the Penn State study specifically recruited healthy, postmenopausal women with known, historic caffeine consumption and because caffeine was measured by chemical analysis, the data are more definitive.

According to Lloyd, some studies have relied solely on self-reporting by women as a measurement of their caffeine intake, e.g. number of cups of coffee they consume currently versus several years ago. Those studies do not consider errors in judgment nor the amount of caffeine in each woman's average cup of coffee.

Lloyd says that other commonly suspected links to bone loss in postmenopausal women are inactivity, smoking and low calcium intake. Bone loss can lead to osteoporosis and bone fractures. Hormone replacement therapy has been proven an effective treatment for bone preservation.

*CAFFEINE*

Contacts:
M. Steven Bortner (o) (717) 531-8607 (h) (717) 838-5910 e-mail: msb3@psu.edu
Deborah Steele Saline (o) (717) 531-8606 (h) (717) 761-5160