Solar activity at birth predicted infant survival and women's fertility in historical Norway

Abstract

Ultraviolet radiation (UVR) can suppress essential molecular and cellular mechanisms during early development in living organisms and variations in solar activity during early development may thus influence their health and reproduction. Although the ultimate consequences of UVR on aquatic organisms in early life are well known, similar studies on terrestrial vertebrates, including humans, have remained limited. Using data on temporal variation in sunspot numbers and individual-based demographic data (N ¼ 8662 births) from Norway between 1676 and 1878, while controlling for maternal effects, socioeconomic status, cohort and ecology, we show that solar activity (total solar irradiance) at birth decreased the probability of survival to adulthood for both men and women. On average, the lifespans of individuals born in a solar maximum period were 5.2 years shorter than those born in a solar minimum period. In addition, fertility and lifetime reproductive success (LRS) were reduced among low-status women born in years with high solar activity. 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.

Vitamin D

“…A recent large-scale Norwegian study indicates that solar activity at birth predicts infant survival and women's fertility. 71 The authors relate this phenomenon to possible UV-R-related effects on vitamin D and folate and discuss the possible role of vitamin-related gene variants. This study builds on the work of Lucock and colleagues [22][23][24] and is supported by similar earlier large studies that indicate that month of birth 72 and the solar cycle 73 actually influence longevity, with Marzullo and Fraser 58 reporting that the human embryo responds to both photoperiod and oxidant stress and suggest that later life disease correlates could be a consequence of this.…”

Protective effect of curcumin on fertility of rats after exposure to compact fluorescent lamps: An experimental study

“…Also, it is shown that X-rays cause apoptosis in the sexual cells ( 32 ). As well as, it has been shown that UV ray prevents the molecular and cellular mechanisms of sexual growth in the early stages of life ( 33 ). Researchers have shown that high levels of ultraviolet rays have a delayed effect on the retention and production of reproductive cells ( 34 ).…”

Some Near- and Far-Environmental Effects on Human Health and Disease with a Focus on the Cardiovascular System

“…Barker's "developmental" model for the origins of a wide range of chronic diseases links their cause to variations in fetoplacental development, thought to lead to variations in the supply of nutrients to the baby that permanently alter gene expression [84]. In a study of demographic data in historical Norway, the lifespans of individuals born during a span of solar maximum were found to be 5.2 years shorter than those born during a span of solar minimum, while fertility and lifetime reproductive success were reduced among low-status women [85]. Anthropometric measures at birth have also been found to follow about 10.5-and about 21-year cycles [57], perhaps in response to cycles in agriculture, following cycles in weather and climate.…”