The diverse effects of alcohol on health can be confusing, Tucker said, noting that consuming alcohol has been found to both benefit the heart and promote breast cancer. Still, she added, moderate drinking’s promotion of bone health in her research was “larger than what we see for any single nutrient, even for calcium. It’s not ambiguous. It’s very clear.”
In the study, the researchers selected 1,182 men, 1,289 postmenopausal women and 248 premenopausal women – all from 29 to 86 years of age – participating in the Framingham Offspring study to investigate how different types of alcoholic beverages affect bone density.
The results indicated that male drinkers who had just one or two glasses of wine or beer a day had better bone mineral density (BMD) than teetotalers. Those men who drank two or more shots of hard liquor a day, however, had considerably lower BMD than those who had one or two shots daily.
For women, drinking more than two glasses daily of alcohol or wine actually seemed to increase BMD. Tucker, however, said she’s skeptical of the scientific validity of this result, because of the tiny number of women in the study who indulged in more than two drinks a day.
She speculated that at least part of the BMD-building effect of alcohol in men was due to beer’s richness in silicon, which is crucial for bone-building and which has become rare in today’s American diet. She said there weren’t enough beer-drinking women to draw conclusions about how silicon affects female BMD.
Spirits had a negative effect on bone health, Tucker suggested, because they have most beneficial plant substances distilled away – such as red wine’s resveratrol, which contributes to heart health. She conjectured that alcohol may improve BMD by increasing estrogen levels – the same mechanism that has been suggested to account for the higher breast cancer risk seen for women who drink even moderately.