By Marc Sorenson, EdD Sunlight Institute
We have previously discussed information indicating that people who received more sunlight had better brain function, and noted the relationship between Alzheimer’s, autism and other mental disorders and lack of sun. A recent study compared cognitive impairment and sunlight in a 15-year residential history of varying degrees of sunlight exposure. It showed that cognitive impairment in persons who were below the median exposure to sunlight was 88% greater than those who were above the median.
The researchers mentioned vitamin D as a possible mechanism by which sunlight positively influenced cognition, but also remarked that regulation of the circadian rhythm by sunlight could be a factor. These same investigators had previously shown that lower levels of sunlight exposure resulted in a 2.58-times higher incidence of cognitive impairment.
So, if you would like to maintain your cognitive abilities, soak up a little non-burning sunlight!
 Kent ST, Kabagambe EK, Wadley VG, Howard VJ, Crosson WL, Al-Hamdan MZ, Judd SE, Peace F, McClure LA. The relationship between long-term sunlight radiation and cognitive decline in the REGARDS cohort study. Int J Biometeorol. 2014 Apr;58(3):361-70.
 Kent ST, McClure LA, Crosson WL, Arnett DK, Wadley VG, Sathiakumar N. Effect of sunlight exposure on cognitive function among depressed and non-depressed participants: a REGARDS cross-sectional study. Environ Health. 2009 Jul 28;8:34