How does sunlight affect cognitive functioning?

In addition to turning us brown, sunlight has other influences on us. One of its physiological effects has to do with vitamin D, whose blood levels depend basically on sunlight and, less importantly, on nutrition. Skin exposed to UV light produces vitamin D3, which is then transformed by the liver and kidney. Vitamin D is important for bones, its role in depression has been studied and it has also been linked to cognitive functions.
Investigating these questions, Shia T. Kent and her collaborators (2013)have found some relationship between sun exposure and mental functioning, as published in the International Journal of Biometeorology. In their research they used measurements of time of exposure to sunlight and ambient soil temperature and provided via satellite. Data on the cognitive status of the 19,896 participants were obtained from the longitudinal REGARDS study (REasons for Geographic and Racial Differences in Stroke) conducted in 48 of the North American states.
The results of their work showed thatthe degree of exposure to the sun in the last year was related to the level of cognitive decline of the participants, even after controlling for the effects of other variables such as age. Those people who had higher levels of solar radiation had a lower probability of incidence of deterioration in their cognitive functions. This relationship was even stronger for young men who had lived under higher temperatures. The authors propose that this data could be explained by the fact that these people spent more time outdoors during the year prior to the study.
According to Kent and his team, the effect of sunlight on brain health could be explained in two ways. One of them refers to the metabolism of vitamin D, since some recent studies findbetter cognitive functioning associated with higher levels of this vitamin. There are receptors for vitamin D in the brain and it has been suggested that it could act as a neuroprotective factor. The other way has to do withregulation of circadian rhythms by the hypothalamus, a brain structure that controls the levels of serotonin and melatonin, substances that also participate in mental function. The authors stated, however, that research on this topic is still very scarce.
Be that as it may, and with caution not to burn yourself, a little sun seems more than recommended to maintain physical and mental health. And just in case, better if while we sunbathe we practice a little brain training.
Marisa Fernández, Senior Neuropsychologist, Unobrain