Why People Shrink with Age and What You Can Do About It
People shrink with age, and in fact everyone experiences tiny changes in height all the time. Now a new study from a team of international experts reveals what you can do about shrinkage and your height as you get older.
How much do people shrink?
Stand up straight! Every child has probably heard those words from a parent or grandparent, and as adults it is still good advice to follow. Every time you do straighten up, however, you may be a slightly different height.
That’s because people shrink and get back “lost” height every day, according to neurologist Roger Hartl, MD, associate professor of neurological surgery and chief of spinal surgery and neurotrauma at Weill Cornell Medical College in New York City.
In an earlier article appearing in the New York Times, Hartl noted that the amount of daily height fluctuation can be as much as three-quarters of an inch. In addition to daily height changes, there is permanent shrinkage over time.
In fact, if you have noticed that your elderly relatives or friends seem to be shorter than they used to be, that’s because of degeneration of the intervertebral disks, which are mostly water. Aging processes such as poorer circulation and less ability of the disks to reabsorb fluid (which helps you get back so-called “lost” height) results in compression of the disks and as a result, shrinkage, as much as two inches (5 cm) by age 60, noted Hartl.
In the new study, which was conducted by economists from Harvard University, Peking University, and the University of Southern California, it was shown that you can make lifestyle choices as an adult that can impact your height and shrinkage. According to John Strauss, professor of economics at USC and one of the study’s authors, “The evidence shows that it is not only early-life events that are associated with how we age, but health decisions in later life as well.”
The authors examined data from 17,708 adults starting at age 45 and studied loss of height as people age. This study is important, as it offers information on human aging in the most rapidly aging and most populated country in the world. Data were from the China Health and Retirement Longitudinal Study.
Here are some of their findings about shrinkage as people age:
- People who shrunk the most were also more likely to have cognitive difficulties, such as poorer short-term memory or difficulties with basic math
- City dwellers lost less height than did people who lived in rural areas
- Education matters: people who were illiterate shrunk more than did people who finished school
- Average overall amount of height lost was 3.3 centimeters for men and 3.8 centimeters for women
Co-investigator Geert Ridder, of USC, explained that “Some of adult health might be determined by childhood circumstances, but people shrink differentially, and that shrinkage is also a measure of adult health conditions.” Factors that can affect shrinkage include diet, exercise, smoking, and the presence of arthritis, osteoporosis, and inflammation of the spine.
Dr. Hartl emphasized that circumstances that cause interference with microcirculation to the disks, such as obesity, diabetes, and smoking should be avoided, and that activities such as aerobic exercise and a healthful balanced diet can help promote disk health and thus help prevent shrinkage.
Although the study was conducted in China and therefore there are cultural and socioeconomic differences with Western societies, people everywhere lose height as they grow older. Adults can make lifestyle choices every day that can have an impact on the fact that people shrink with age.
Huang W et al. Health, height, height shrinkage, and SES at older ages: evidence from China. American Economic Journal 2013; 5(2): 86
New York Times: Thinking about shrinkage.