Being born in the fall may extend a person's lifespan by a few months.
A study appearing today in the Proceedings of the National Academy of Sciences linked the birth months of more than a million people who died in Denmark and Austria after the age of 50. It then looked for a similar pattern in Australia.
The study found that adults who were born in Austria between October and December lived about .6 years longer than those born in the spring, April to June.
In Denmark, those born in the fall lived about .3 years longer than did people born in the spring, the study found.
The authors, Gabriele Doblhammer and James W. Vaupel of Max Planck Institute in Rostock, Germany, also checked the pattern of birth month and lifespan in Australia and found "a mirror image reversal of that in the Northern Hemisphere."
"The mean age of death of people born in Australia in the second quarter of the year is 78," the authors said. "Those born in the fourth quarter die at a mean age of 77.65."
The authors said the difference may be related to nutrition during pregnancy. More fruits and vegetables are available during the summer and fall months than during the winter and spring months, the authors said.
This means that a woman pregnant during the summer and fall could have a better food selection and their babies would be larger and healthier.
Opposite Hemispheres, Mirror Images
Since the seasons in Australia, in the Southern Hemisphere, are the opposite of the seasons in Europe, this would explain why the Australian pattern is a mirror image of the Austrian and Danish patterns, the researchers said. Fresh fruits and vegetables are more readily available in Australia during the first half of the year, which are the summer and fall months south of the equator.
Doblhammer and Vaupel noted that there are many studies showing that nutrition of a woman during pregnancy can affect the health of her baby for its lifetime.
"The environment early in life affects the susceptibility of adults to infections as well as chronic diseases," the researchers said in the study.