T. Lloyd et al., Bone status among postmenopausal women with different habitual caffeine intakes: A longitudinal investigation, J AM COL N, 19(2), 2000, pp. 256-261
Objective: Caffeine consumption has been proposed as a risk factor for bone
loss in postmenopausal women. past epidemiologic studies on caffeine and b
one have been confounded by covariates including cigarette and alcohol use.
differing levels of physical activity and hormone replacement therapy. The
purpose of the study was to use a longitudinal design to determine the rel
ationship between habitual dietary caffeine intake and postmenopausal bone
status.
Methods: Data were collected at two time points separated by two years; 138
women with little or no exposure to tobacco or to drugs known to affect bo
ne status were seen at Visit 1, and 112 returned for Visit 2. Ninety-two of
these subjects had received no drugs known to affect bone status over the
two-year interval and were kept in the sample. Nutrient and caffeine intake
were assessed from three-day dirt records. Bone measurements were made by
dual energy x-ray absorptiometry (DSA).
Results: Correlation analyses indicated no association between dietary caff
eine intake and total: body or femoral neck bone density or bone mass. Simi
larly, no associations were found between caffeine consumption and longitud
inal changes in total body or femoral neck bone measurements. These results
held true both with and without statistical adjustment for calcium intake.
Conclusions: This study does not support the idea that caffeine is a risk f
actor for bone loss in healthy postmenopausal women.