In an interesting study, it was found out that in two countries of the Northern Hemisphere–Austria and Denmark– people born in autumn or between October and December live longer compared to those born in spring or from April to June.
Authors of the study Gabriele Doblhammer and James W. Vaupel, who have conducted the study on the subject for over a decade, said the data when compared to Australia shows that, in the Southern Hemisphere, the pattern is shifted by half a year.
The lifespan pattern of British immigrants to Australia is similar to that of Austrians and Danes and significantly different from that of Australians, they said in their study.
The findings are based on population data with more than a million observations and the differences in lifespan are independent of the seasonal distribution of deaths and the social differences in the seasonal distribution of births, according to the abstract published in PNAS.
In the Northern Hemisphere, the excess mortality in the first year of life of infants born in spring does not, however, support the same view about the infant survival but remaining life expectancy at age 50 appears to have been affected by factors that arise in utero or early in infancy and that increase susceptibility to diseases later in life, said reserchers.
The finding has virtually reversed the century-old belief that infants born in autumn had higher birth weight than those born in other seasons and so is their lifespan rate.
Further, differences in adult lifespan by month of birth decrease over time and are significantly smaller in modern times due to technology and immigration, besides substantial improvements in maternal and infant health, said the study.