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Excessive alcohol consumption can affect bone health

Terrence Donohue Jr., Ph.D., UNMC professor of internal medicine, is an expert on the effects of alcohol on the liver. He and colleague, Dennis Chakkalakal, Ph.D., associate professor in the Department of Surgery at Creighton University, say chronic consumption of excessive alcohol can inhibit the formation and function of new bone cells called osteoblasts.

The result is decreasing new bone formation required for maintenance of bone health and healing after bone injuries.

Dr. Chakkalakal is author of a review published in the December issue of “Alcoholism: Clinical & Experimental Research.” The review, “Alcohol-Induced Bone Loss and Deficient Bone Repair,” was funded by the Department of Veterans Affairs and by Creighton University Medical Center.

The two scientists work at the Omaha Veterans Affairs Medical Center and have studied the relationship of alcohol on health for several years. They receive funding from agencies including the VA and the National Institute of Health Alcohol Abuse and Alcoholism.

Chronic and heavy alcohol consumption is known to contribute to low bone mass, decreased bone formation, an increased incidence of fractures and delays in fracture healing. A review of human, animal and cell-culture studies of alcohol’s detrimental effects on bone has determined that osteoblast development and function are particularly at risk.

“Many people know about alcohol’s effects on the liver and the damage it can cause to this organ after years of heavy drinking,” said Dr. Donohue, an expert on alcohol and the liver. “Considerably fewer people know about alcohol-induced bone disease.”
It is not known exactly how alcohol affects bone thinning and fractures, nor how long or how much alcohol consumed would affect bone health.

“Each type of alcoholic beverage (i.e. beer, wine or distilled spirits, such as whiskey) has a different gram quantity of alcohol in the form of ethyl alcohol or ethanol. Both the amount of alcohol and the duration of its consumption are very important in producing liver disease,” Dr. Donohue said. “That’s been shown in the liver. It also has been shown epidemiologically, because during the years of prohibition, the liver cirrhosis rate declined, which means that people were drinking less and therefore the incidence of liver disease was less. Then, when prohibition was repealed, the rate of liver cirrhosis went back up as drinking increased.”

“The maintenance of healthy bone in human adults occurs through a process called ‘bone remodeling,’ ” said Dr. Chakkalakal, author of the review. “At any given time during adult life, and in various parts of the skeleton, small portions of the ‘old bone’ are removed by cells called ‘osteoclasts’ and new bone is formed by cells called ‘osteoblasts.’ In a healthy person, the two activities are in balance so that there is no net loss of bone.”

However, chronic and heavy drinking can disrupt the balance by suppressing new bone formation.

“The empty space created by normal bone-removing activity is inadequately filled by newly formed bone,” Dr. Chakkalakal said. “This process continues at other skeletal sites during the next remodeling cycle.

“The cumulative effect of this process during several remodeling cycles is manifested as measurable bone loss over a period of just a few years. The few studies that have been done on the effects of both the amount of alcohol consumed daily and the duration (years) indicate that bone loss may be seen within 3 to 10 years in alcoholics who consume 100 grams of alcohol (roughly, eight beers, nine glasses of wine or seven mixed drinks) daily.”

He said alcohol-induced bone loss weakens the bones and predisposes alcoholics to a greater frequency of fractures from falls.

In order to heal properly, bone cells must first form a ‘matrix’ that later hardens or ossifies to form new bone, said Drs. Chakkalakal and Donohue. Alcohol consumption changes the composition of this matrix by suppressing the formation of osteoblasts and/or decreasing their ability to respond to signals that normally trigger bone formation after a fracture.

The evidence also supports the choice of abstinence from alcohol. “The review underscores the importance of abstinence from alcohol consumption by patients with fractures and who may want to drink during their convalescence,” Dr. Donahue said.