The season of birth may be related to your risk of dying from heart disease later in life. This emerges from a large US study in the Christmas issue of the British Medical Journal. The results show that the number of people born in the spring and summer had a small but significant increase in death from heart disease compared to those born in the fall.
Season of birth - connections
The reasons for the differences between seasons are not exactly known. However, they can include seasonal variations in diet, air pollution, and sunlight availability early in life. Previous studies in the Northern Hemisphere have consistently linked spring and summer births to a higher risk of death. This was consistent with the reverse pattern south of the equator. However, they were not a sufficient basis for factors such as family medical history or economic and social status.
To overcome these limitations, researchers used data for 116,911 U.S. nurses. They were included in a study in 1976 to examine connections between the timing of childbirth and death in general, as well as death from cardiovascular disease. Participants were 30 to 55 years old at the start of the study and completed a detailed health and lifestyle questionnaire every two years. The scientists also used death certificates and medical records to identify the causes of death over 38 years (1976-2014).
The researchers documented more than 43,000 deaths during the study period. Of these, 8,360 deaths occurred due to cardiovascular diseases. However, unlike previous studies, no significant association was found between the season of birth and death in general.
However, taking into account a range of family history, economic and social factors, the researchers found that women born in the spring and summer had a small but significant increase in cardiovascular death compared to women born in the fall. So this is an observational study. For this reason, scientists cannot determine a cause. However, the researchers cannot rule out that some of the results are due to unmeasured factors.
Risk factors
However, the strengths of the study include the size of the sample. In addition, the long follow-up examination and detailed information on lifestyle, family history, social and economic factors are just as important. As such, the researchers say their study “adds to the growing body of evidence.” These suggest that individuals born in spring and summer have higher cardiovascular mortality. However, they are inconsistent with previous results on all-cause mortality.”
It also supports the view that the association of fetal and early life factors with cardiovascular disease mortality “may be related to a small but real seasonal effect of fetal or early life factors in later life,” they add.
“Further research is needed to confirm the current results and uncover mechanisms for the seasonal birth month effect in cardiovascular mortality,” they conclude. You can find the link to the studyhere.
