In a study of 489 post-menopausal women, moderate drinkers had significantly higher bone mineral density (BMD) than their nondrinking counterparts, according to research by Rapuri et al. published in The American Journal of Clinical Nutrition. Although the bone-protective effects of alcohol have been noted in previous research, this study provides new evidence that moderate alcohol consumption appears to decrease the rate of bone turnover. This effect may result from reduction in the level of parathyroid hormone which regulates the ongoing process of bone remodeling. The maximum positive effect of alcohol consumption on bone was seen in postmenopausal women who ingested >28.6 to 57.2 grams of alcohol per week, about the equivalent of 2-4 mixed drinks, glasses of wine, or cans of beer. The women had 16% greater BMD in the spine, 12% greater total body BMD, and 14% greater forearm BMD than did nondrinking women.
Information on smoking history, past use of estrogen, present use of medications or a history of fractures was adjusted in statistical analysis. Dual X-ray absorptiometry was used to measure BMD at the hip, lumbar spine, whole body, and forearm skeletal sites. Blood levels of several bone marker chemicals and the parathyroid hormone were also obtained. Women identified as moderate drinkers (>28.6 to 57.2 g/wk) were found to have the highest BMD at every skeletal site, though the difference at the hip was not as significant as at the other sites. Serum parathyroid hormone (PTH) was 25-30% lower in moderate drinkers than in nondrinkers.
Serum levels of PTH are the principal determinants of bone remodeling. The significantly lower PTH concentration found in subjects who were moderate drinkers was one cause of a reduction in bone resorption and resultant greater BMD. After adjustments for age at menopause, which occurs about two years later in drinkers than in nondrinkers, a further explanation for the increase in BMD was hi
Contact: Beth M. Wettergreen
American Journal of Clinical Nutrition