The light of life: evidence that the sun modulates human lifespan.

UNLABELLED This paper describes the effects of radiation, probably ultraviolet radiation (UVR), on the human genome at peaks of solar cycles. This phenomenon was not previously reported because peak cycle lifespan had not been separated from non-peak lifespan. This paper reinforces the findings of others regarding the seasonality of various diseases and that there are factors occurring early in utero that increase susceptibility to diseases later in life. The authors use the vital statistics of 320,247 Maine citizens over a 29-year period to show that those born in 3-year peaks of 11-year solar cycles live an average of 1.5 years (CL 1.3-1.7) less than those born in non-peak years. Males are more sensitive than females to this phenomenon, which is statistically demonstrable well into adult life, showing the effect of probable UVR on the early human embryo despite superimposed adult lifetime hazards. The authors also show that changes in seasonal light modulate lifespan differently in males and females and that genome and environment must be tightly interactive early after conception. Published literature supports the hypothesis that UVR suppresses the maternal immune system by producing cytokines in circulating lymphocytes that probably affect the fetal genome. The intermittent and incompletely predictable solar cycles periodically stress the genomes of all life producing genetic changes which may be harmful or adaptive. The evidence presented in this study indicates that solar cycles, particularly the most irradiant which have occurred over the past 65 years, are fundamental engines of evolution, even underlying natural selection, and we bear their marks even to the end of our lives. Future researchers must further define the pathogenesis of solar radiation on early embryonic development to possibly minimize a predisposition to diseases at their origin. BACKGROUND/PURPOSE This study explores the relationship of season of birth and human lifespan particularly in reference to the intensity of solar radiation that occurs in 11-year cycles. METHODS The birth years were obtained and lifespan calculated for 320,247 Maine citizens over a 29-year period. Those who were born at 3-year peaks of 11-year solar cycles were separated from those born in non-peak years. Using SAS statistical tools, a randomization technique was used to compare the lifespan between peak and non-peak years to eliminate selection bias, cohort effects, and confounding variables. RESULTS Those born in peaks of solar cycles lived an average of 1.5 years (CL 1.3-1.7) less than those born in non-peak years. Males were more sensitive to this phenomenon than females. A similar analysis was performed for month of birth and the pattern of peak to non-peak lifespan difference was nearly identical to the pattern of seasonal variation in light. CONCLUSIONS Lifespan variation appears to be modulated by seasonal light confirming that genome and environment are closely linked very early after conception. Although the precise pathogenesis is still unknown, the phenomenon must involve radiant energy, probably ultraviolet light, possibly affecting the maternal immune system through the dermis. This study also supports the reliability theory of aging which suggests that events affecting the genome early after conception are important in the expression of adult diseases.