BOSTON, Mass. — If you’re a believer in astrology, you’re at least partial to the idea that the date of your birth may be influencing your actions, disposition, and decisions. Now, a startling new study conducted at Harvard finds that those born in warmer months may be at a greater risk of dying due to heart disease.
According to the findings, people born during the spring and summer are at a slightly, but nevertheless significant, greater chance of dying due to heart problems than people born during autumn. While the study’s authors can’t say for sure what is causing this phenomenon, they theorize it could be connected to seasonal differences in expectant mothers’ diets, air pollution fluctuations, and amount of sunlight both before birth and in early infancy.
If all of this sounds too farfetched for your tastes, consider this: previous research had already found that people born in the northern hemisphere during spring and summer are at a higher risk of death. However, research conducted in the southern hemisphere actually found the exact opposite (those born during winter / fall are at greater risk of death). Though, none of this previous research had controlled for other factors like family medical history or economic status.
So, in an effort to more comprehensively investigate the matter, this study’s authors utilized data on 116,911 American female nurses collected over 38 years (1976-2014). Initially, the nurses were between the ages of 30-55 and filled out a health and lifestyle survey every two years, beginning in 1976.
During the follow-up period, more than 43,000 deaths occurred, including 8,360 cardiovascular disease-related deaths.
Interestingly, dissimilar to previous research, no association was found between birth months and risk of overall death. However, regarding heart disease, the researchers did in fact find that women born during warmer months had a slightly higher rate of cardiovascular deaths in comparison to women born in the fall. This held true even after accounting for outside factors.
Overall, the study’s authors believe their work “adds to the growing evidence suggesting that individuals born in the spring and summer have higher cardiovascular mortality than those born in autumn, but conflicts with previous findings on overall mortality.”
Ultimately, though, this study was observational, and further research is needed in order to verify its findings.
The study is published in The BMJ.