Birth Month Linked to Lifelong Disease Risks

A significant analysis of medical records indicates a potential link between an individual's birth month and their lifetime disease patterns. This 2015 study, published in the Journal of the American Medical Informatics Association, examined approximately 1.75 million people's electronic health records in New York City. It identified 55 diseases with notable associations to the month of birth. While May births were linked to the lowest overall disease risk, those born in October faced the highest. However, the risks varied by disease category, with October births sometimes showing lower cardiovascular disease risk despite higher respiratory risks. Researchers propose that birth month acts as a marker for seasonal exposures during pregnancy or around the time of birth, influencing development. These exposures can include varying levels of sunlight, temperature, air pollution, allergens, maternal nutrition, and vitamin D status. These seasonal environmental factors are considered more likely influences than the birth month itself. Furthermore, six cardiovascular conditions identified showed relationships with previously reported lifespan patterns by birth month, suggesting a potential partial explanation for observed longevity differences. The study's authors caution that findings may be specific to the climate and environmental conditions of New York City, and seasonal effects could differ in other regions like India. They emphasize that the overall disease risk related to birth month is minor compared to influential variables like diet and exercise, and there is no reason for alarm based solely on one's birth certificate.