The effect of moderate alcohol consumption on bone mineral density: a study of female twins.

BACKGROUND Osteoporosis is associated with morbidity and mortality, particularly in postmenopausal women. The effect of moderate alcohol intake on bone mineral density (BMD) and fracture risk remains unclear. OBJECTIVE To carry out a twin study to investigate this effect while controlling for genetic effects and other confounding variables. METHODS BMD was determined at the hip and lumbar spine in 46 pairs of monozygotic twins discordant for alcohol consumption. Biochemical evidence of altered bone metabolism was sought. RESULTS A positive association between alcohol consumption and BMD was shown, in contrast to the negative effect of smoking on BMD. Markers of bone turnover were not associated with alcohol or BMD. CONCLUSIONS Moderate alcohol consumption is not harmful to bone health in women and may even be beneficial. Beneficial effects do not appear to be mediated through an action on bone metabolism.