Adult survivors of populations that had high levels of childhood infection are shorter in stature and die younger than those who lived in times of lower infection rates, according to a new study based on historical data. The researchers link the problems to the negative health effects of chronic inflammation.

In England, France, Sweden and Switzerland in populations born before 1899, the scientists found that infant mortality rates, an indicator of exposure to infection, highly correlated to deaths from heart and circulatory diseases 40 to 69 years later.

The problem, the authors said, is that people who live with high childhood infection levels carry elevated circulating levels of inflammatory proteins throughout their lives. That leads to more risk for heart attack and stroke. The paper appears today in The Proceedings of the National Academy of Sciences.

Height, the researchers found, is also affected. People who have lived in highly infectious childhood environments are, on average, shorter than those who have not. The reason is that energy that the immune system uses would under healthier conditions increase growth. The effect persists in certain regions with widespread childhood infection, but will soon die out in Western industrialized countries.

"For much of the world," said Eileen M. Crimmins, a professor of gerontology at the University of Southern California and the lead author on the study, "people will now be aging with less time spent with high inflammation. With public health improvements and immunizations, many of the sources of infection and inflammation have been eliminated, at least in some populations."