Alcohol's harmful effects on bone

Abstract

Long-term alcohol consumption can interfere with bone growth and replacement of bone tissue (i.e., remodeling), resulting in decreased bone density and increased risk of fracture. These effects may be exerted directly or indirectly through the many cell types, hormones, and growth factors that regulate bone metabolism. Alcohol consumption during adolescence reduces peak bone mass and can result in relatively weak adult bones that are more susceptible to fracture. In adults, alcohol consumption can disrupt the ongoing balance between the erosion and the remodeling of bone tissue, contributing to alcoholic bone disease. This imbalance results in part from alcohol-induced inhibition of osteoblasts, specialized cells that deposit new bone. Some evidence suggests that moderate drinking may decrease the risk of fracture in postmenopausal women.

Figure 1

A section of the upper end of the long bone of the thigh (i.e., the femur). The ball at the upper left forms part of the hip joint. The walls of the shaft (C) are mainly cortical bone; the bone nearer the ends (T) is cancellous bone.

Figure 2

The effect of alcohol on the microscopic structure of long bones in the rat. The sections show the upper end of the tibia, the lower leg bone that forms part of the knee joint. Compared with normal bone (2a), tibiae from rats administered alcohol (2b) exhibit more compact cortical bone (C) and significantly less cancellous bone. T indicates a single trabeculum, one of the structural units of cancellous bone.

Figure 3

Microscopic view of a bone-resorbing cell, or osteoclast (see arrow).

Figure 4

Microscopic view of bone-forming cells, or osteoblasts (arrow), showing a newly formed layer of unmineralized bone matrix (o) and an older layer of mineralized bone (mb). Occasionally, osteoblasts become embedded within the mineralized matrix, losing their bone-forming ability (oc).