Lifestyle factors can influence how much we shrink as we get older, according to a new study from U.S. and Chinese researchers.
The study, published in the American Economic Journal: Applied Economics, shows correlations between lifestyle choices -- such as level of education completed and type of living area (rural or urban) -- and getting shorter among people in China.
"Had we only examined the correlations between measured height and health, we would have missed this important insight," study researcher John Strauss, a professor of economics at the University of Southern California, said in a statement. "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 study included data from 17,708 adults from the China Health and Retirement Longitudinal Study, who were followed starting at age 45 every two years. All of the people in the study were from 150 different counties in China. Researchers analyzed a number of lifestyle factors in association with height loss as they aged.
They found, for example, that completing primary school was linked with 0.9 centimeters less in height loss, compared with people who can't read or write. And people who lived in urban areas also were less likely to decrease in height with age than those in rural areas, researchers found.
Height loss is a natural part of getting older, due to loss of muscle mass, flattening foot arches and fluid loss in vertebrae disks. But too much height loss can raise risk of fractures and heart disease for men, the Wall Street Journal pointed out. And researchers in the new study noted that height loss may also be correlated with cognitive problems, such as memory loss.
NBC News reported that a person will lose around one to three inches in total with age. To help prevent height loss, healthy habits include not smoking, not drinking too much alcohol, taking steps to prevent falls, getting adequate vitamin D and calcium, and doing muscle-strengthening exercises.