It is generally assumed that economic downturns increase mortality. However, Granado and Roux found that people were healthier during the Great Depression of 1930-1933.
Contrary to expectations, mortality declined during the 4 years of this depression. Mortality declined for almost all ages and life expectancy increased by 6.2 years for males, females, whites and nonwhites. Suicides were an exception, with an increase occurring during the depression. Opposite to what was expected, infant mortality declined in spite of increased malnutrition among low-income groups and increased infant mortality in some areas subjected to very high unemployment.
These mortality trends were also found to slow or reverse during periods of economic expansions but accelerated during recessions.
The authors of the study could not definitively explain the reasons for this reduced mortality, but speculated that reduced smoking and alcohol consumption, less driving and fewer industrial injuries may explain their findings. Another possibility not mentioned in the paper includes families with reduced income that could only afford basic foods and experienced reduced calories due to avoidance of expensive or unessential processed foods.
Source: Granado JAT, AVD Roux. Life and death during the Great Depression. Proceedings of the National Academy of Sciences. 2009, 106, 17290-17295.