Diet and lifestyle associated with increased bone mineral density: cross-sectional study of Japanese elderly women at an osteoporosis outpatient clinic

Background. Several studies have already demonstrated that lifestyle characteristics, such as physical activity, smoking, and alcohol intake, are associated with bone mineral density (BMD). Coffee intake was shown to be negatively associated with BMD, whereas tea drinking was reported to be associated with increased BMD. A review of the literature, however, revealed that few studies have described the association between BMD and lifestyle, including characteristic Japanese foods such as fish, natto, and Japanese green tea. The aim of this study was to identify lifestyle factors associated with BMD. Methods. A total of 632 women age >= 60 years were enrolled in this study. Subjects were interviewed about their lifestyle by means of a questionnaire regarding the consumption pattern of dietary items. BMD was measured at the lumbar spine by dual energy X-ray absorptiometry. Results. The BMD was higher in subjects with the habits of alcohol drinking, green tea drinking, and physical activity and lower in those with the habits of smoking and cheese consumption. Multiple regression analysis showed that factors associated with BMD were smoking, alcohol consumption, green tea drinking, and physical activity after adjusting for age and body mass index (BMI). Conclusions. In this cross-sectional study at an osteoporosis outpatient clinic, patients with the habits of alcohol drinking, green tea drinking, and physical activity had significantly higher BMD, and those who smoked had significantly lower BMD than patients without each habit after adjusting for age, BMI, and other variables regarding lifestyle.