Coffee consumption and bone mineral density in korean premenopausal women.
Although Asian people are known to have lower bone mass than that of Caucasians, little is known about coffee-associated bone health in Asian. This study aimed to assess the relationship between coffee consumption and bone mineral density (BMD) in Korean premenopausal women.
Data were obtained from the Fourth Korea National Health and Nutrition Examination Survey 2008-2009. The study population consisted of 1,761 Korean premenopausal women (mean age 36 years) who were measured for lumbar spine and femoral neck BMD and who completed a standardized questionnaire about coffee intake frequency. We excluded the participants who took hormone replacement therapy or medication for osteoporosis. The cross-sectional relationship between coffee consumption and impaired bone health (osteopenia or osteoporosis) was investigated by bone densitometry.
Coffee consumption showed no significant association with BMD of either femoral neck or lumbar spine, independent of other factors. The adjusted odds ratios for BMD for those who consumed once in a day, twice a day and three times a day were 0.94 (0.70-1.26), 0.93 (0.67-1.28), and 1.02 (0.69-1.50), respectively (P for trend = 0.927).
This study does not support the idea that coffee is a risk factor for impaired bone health in Korean premenopausal women.
This study shows that high consumption of coffee is not associated with increased risk for impaired bone health. Our results are in agreement with some recent cross-sectional studies showing no association between caffeine and impaired bone health, and in disagreement with others which focused on BMD of various skeletal sites.22-26) Habitual dietary caffeine intake was found not to be associated with impaired bone health in healthy postmenopausal women in a longitudinal study in Pennsylvania (USA), on the basis of self-reported questionnaires collected in 2000.23) In elderly men and women from the population-based Framingham Osteoporosis Study, the same results were found.24) These studies are in agreement with our study. Although the frequency consumed and the species of coffee could be significantly affected by cultural differences and socioeconomic status, and the metabolism of caffeine and other constituents can be affected by genetic predisposition, our results in Korean premenopausal women did not appear to contradict those of previous studies.
The role of coffee intake in bone health, however, seems controversial. There are several studies showing a negative association between caffeine and bone health. Daily intake of 330 mg of caffeine, equivalent to 4 cups (600 mL) of coffee, or more may be associated with a modestly increased risk of osteoporotic fractures, especially in women with a low intake of calcium, as shown in a study on Swedish women aged 40 to 76 years.4) Also, in a cohort study, Men consuming 4 cups of coffee or more per day had 4% lower BMD at the proximal femur (P = 0.04) compared with low or non-consumers of coffee. This difference was not observed in women, suggesting that rapid metabolizers of caffeine may constitute a risk group for bone loss induced by coffee.24)