Bone loss is an often-overlooked consequence of heavy drinking, but recent research has illuminated how alcohol takes a toll on the bones.
In a review of cell, animal and human studies, Dr Dennis A. Chakkalakal of the Omaha VA Medical Center in Nebraska describes how heavy drinking leads to bone loss, higher risk of fractures and slower healing of bone breaks.
The main problem appears to be that alcohol inhibits the normal formation of new bone, Chakkalakal reports in the journal Alcoholism: Clinical & Experimental Research.
Though excessive drinking has been shown to promote bone thinning and fractures, some studies have suggested that moderate drinking may help protect bone mass — possibly because small amounts of alcohol promote new bone formation.
The opposite appears true of high amounts of alcohol, according to Chakkalakal's review.
Throughout adulthood, bone undergoes a process of "remodeling," whereby cells called osteoclasts break down small portions of old bone, and cells called osteoblasts form new bone. In healthy, younger adults, this process is usually balanced, so that bone mass is maintained.
Too much alcohol, however, appears to inhibit osteoblasts from doing their job, and heavy drinkers may start to lose bone mass in just a few years, according to Chakkalakal. The potential for bone loss climbs in tandem with drinking, evidence shows, but it's not clear where the risk threshold lies.
Most studies on alcohol and bone loss have defined "heavy" drinking as roughly six or more drinks per day. But, the review points out, there's some evidence that bone loss is a risk for people who have closer to three or more drinks a day, Reuters reports.