Short but True: The Real Reason We Lose Height with Age
Most adults lose height as they age. What causes this? Scientists have different opinions on the matter. Some say it's the reduced height of the discs between the bones in the spine (vertebrae). Thinning and loss of fluid cause discs to lose height with age. Other scientists suggest that the true height of discs actually increases with age. With this thinking, loss of stature is mainly caused by the bones getting compressed.
Pondering this question, researchers in Germany studied X-rays of over 1,200 adults. Both the discs between the vertebrae and the vertebral bones were measured using a new, more accurate method.
The purpose of the study was to collect a bank of information called a baseline. This gives researchers a place to start when comparing one person to the next. It also tells them more about what happens to the height of discs and the shape of vertebrae with age.
The results of the study were surprising. The discs in the low back actually increased in height until people reached the age of 70. This was true for both men and women. At the same time, the main part of the vertebral bones got smaller with age. The middle of the bones actually appeared to sink in. This is referred to as increased concavity.
Data collected from a large number of back X-rays answered some important questions. The loss of height that comes with age is caused by changes in the bone, not changes in the discs between the bones. This information will help doctors compare patients' X-rays to "normal" adults at various ages.
Zengwu Shao, MD, et al. Radiographic Changes in the Lumbar Intervertebral Discs and Lumbar Vertebrae With Age. In Spine. February 1, 2002. Vol. 27. No. 3. Pp. 263-268.