WASHINGTON - A University of Michigan study has shown that U.S. life expectancy increased by 6.2 years during the Great Depression.

Published in the Proceedings of the National Academy of Sciences, the study showed that life expectancy rose from 57.1 in 1929 to 63.3 years in 1932.

“The finding is strong and counterintuitive. Most people assume that periods of high unemployment are harmful to health,” said Jose Tapia Granados, the lead author of the study and a researcher at the U-M Institute for Social Research (ISR).

Tapia Granados, who carried out this study in collaboration with Ana Diez Roux, said that the increase occurred for both men and women, and for whites and non-whites.

For the study, the researchers used historical life expectancy and mortality data to examine associations between economic growth and population health for 1920 to 1940.

Upon analyses of the data, the observed that while population health generally improved during the four years of the Great Depression and during recessions in 1921 and 1938, mortality increased and life expectancy declined during periods of strong economic expansion, such as 1923, 1926, 1929, and 1936-1937.

The researchers analysed age-specific mortality rates and rates due to six causes of death that composed about two-thirds of total mortality in the 1930s: cardiovascular and renal diseases, cancer, influenza and pneumonia, tuberculosis, motor vehicle traffic injuries, and suicide.

They note that the association between improving health and economic slowdowns was true for all ages, and for every major cause of death except one: suicide.

The study did not include analyses of possible causes for the pattern, but Tapia Granados and Diez Roux offer some possible explanations about why population health tends to improve during recessions but not expansions.

“Working conditions are very different during expansions and recessions. During expansions, firms are very busy, and they typically demand a lot of effort from employees, who are required to work a lot of overtime, and to work at a fast pace. This can create stress, which is associated with more drinking and smoking,” Tapia Granados said.

“Also, new workers may be hired who are inexperienced, so injuries are likely to be more common. And people who are working a lot may also sleep less which is known to have implications for health. Other health-related behaviours such as diet may also change for the worse during expansions,” the researcher added.

In recessions, according to Tapia Granados, there is less work to do, which is why employees can work at a slower pace.

In such periods, people also get more time to sleep, and since they have less money, they are less likely to spend as much on alcohol and tobacco.

Furthermore, economic expansions are also associated with increases in atmospheric pollution which has well-documented short-term effects on cardiovascular and respiratory mortality.

Suggesting another reason as why economic expansion may be bad for health, the researchers say that it could include increases in social isolation and decreases in social support, which typically occur when people are working more.

Tapia Granados hopes that a better understanding of the beneficial effects of recessions on health may perhaps contribute to the development of economic policies that enhance health and minimize or buffer adverse impacts of economic expansions.

He cautions that the study also suggest that suicide prevention services-often the casualties of budget cuts during economic downturns-are more important during bad times than ever. (ANI)