Health Benefits of Sunlight

People seem to have a powerful natural instinct to be in sunlight. Ask somebody where they would like to go for a holiday, and the chances are they’ll tell you they would like to go somewhere warm and sunny. We seem to know that being outdoors and in sunlight is good for us, but for many years we’ve been told to avoid the sun. It’s certainly true that being sunburnt is bad for you and increases the risk of melanoma. However, recent research has found what we all felt in our bones – that (non-burning) sunlight is good for us. Even our pets appear to know this, rushing outdoors to lie in the sun. An excellent paper that reviews these recent discoveries is “Melatonin and the Optics of the Human Body” by  S. Zimmerman and R. J. Reiter in Melatonin Research 2019, see:

This paper describes the way in which certain wavelengths of sunlight, known as Near Infra-red Radiation, or NIR, produces melatonin in the mitochondria (the power producers) in the majority of our cells, including the major organs, skin, brain, gastrointestinal tract, eyes, etc . Melatonin is a powerful anti-oxidant and when produced inside cells it effectively mops up the highly damaging reactive oxygen species (ROS) that are produced by mitochondria as a normal part of living (breathing oxygen). So, NIR-induced melatonin prevents ROS from causing cell damage, inflammation, and cell death. Although more research is needed, it seems likely that without exposure to NIR our bodies will have a lot more inflammation.

This knowledge is starting to be utilised for therapy, with NIR phototherapy treatments for wound healing, dementia, eye disease and PTSD, and lamps can be purchased for this. However, non-burning sunlight also has this effect. NIR radiation is able to penetrate light clothing and even penetrates through the skull. NIR also goes through sunblock, so you can be sun-safe and still get a good dose of healing NIR outdoors.

NIR exposure might be especially important post-op, when many people are confined indoors where they won’t receive NIR. Indeed, in the old days many hospitals had outdoor “rooms” so their patients could be in sunlight. For good video explainers about the health benefits of sunlight, see these Medcram YouTube links:

This video explains how Vit D is one important aspect of the health benefits of sunlight, but it isn’t the full story at all: