Our sun has an 11-year cycle of solar activity that impacts both human fertility and human mortality rates. Solar activity cycles are predictable, according to the National Weather Service, and follow a pattern of eight years of low solar activity, which is followed by three years of high solar activity. Solar activity measurements count how many sunspots are seen coming from the sun’s surface.
According to new research that was published in the Proceedings of the Royal Society B, years of high solar activity are among the more dangerous years to be born.
The researchers looked at church records from the timespan between 1750 and 1900 from two areas in Norway. All total, 9,062 people’s lives were examined. The researchers looked at their personal histories. They assessed how old women were when they had their children, how many children they had, and how many children survived. From there, the researchers also looked at marriage records and subsequent fertility rates.
Gine Roll Skjærvø led a team at the Norwegian University of Science and Technology. The researches looked at various environmental factors and found a strong link to the number of sunspots and fertility and mortality. Children who were born in the three years of the solar cycle when solar activity peaked had the highest mortality. People born during the years of the highest solar activity lived, on average, five and two-tenths less years than people born during the eight years of lowered solar activity during each 11-year cycle. The greatest mortality was found during the first two years of life. Infants were more likely to die if they were born during a time of greater solar activity.
“Skjærvø and her colleagues found that children born in years with lots of solar activity had a higher probability of dying compared to children who were born in years with less solar activity,” reported a Science Daily writer.
Interestingly, heightened solar activity during infant girl’s birth years also decreased those girl’s future fertility potential. In other words, if someone wants a lot of grandchildren, they should plan to be pregnant during a year when the sun is less active.
“In addition, fertility and lifetime reproductive success were reduced among low-status women born in years with high solar activity.”
The authors pointed out that people with low socioeconomic status were the most likely to be affected by solar activity. The team surmised that access to proper nutrition probably was a factor in a person’s susceptibility to DNA damage. Good nutrition during pregnancy, especially folate consumption, has been proven to decrease DNA damage to developing fetuses and UV radiation can cause a person to lose vitamin B9, also known as folate. Women need 400 micrograms (mcg) of folic acid every day or a diet high in natural folate, according to the CDC.
“All women of reproductive age need to follow a healthy lifestyle, whether or not they’re planning to have a baby” Dr. Bruce Young explained previously in a report from the Taos News. “It is important that women, even at an early age, become vigilant about having folic acid in their diets.”
Folate helps our bodies make DNA and RNA, the body’s genetic material, according to the University of Maryland Medical Center, and “is especially important when cells and tissues are growing rapidly, such as in infancy, adolescence, and pregnancy.”
The researchers theorized about the possible explanation in the Norway paper that implicated solar activity in lowering fertility and increasing mortality, especially because of the link between the severity of the sun’s effects and the individuals’ socioeconomic status.
“The proximate explanation for the relationship between solar activity and infant mortality may be an effect of folate degradation during pregnancy caused by UVR. Our results suggest that solar activity at birth may have consequences for human lifetime performance both within and between generations.”
If people want to use the researchers’ findings to their advantage when planning pregnancies, the NASA/Marshall Space Flight Center has predictions for solar activity displayed in a handy chart. The authors of the Norway paper did mention that light skin might make a person especially susceptible to reduced fertility and increased mortality if they are born during the years of high solar activity.
[Photo via Pixabay]