Research suggests individuals soak up sun light in order to attain numerous health benefits. A prime reason for this is the release of vitamin d from the skin which is known to ameliorate many conditions. A belief about sun exposure may be prevalent amongst many in modern times. However, this belief may need to be changed to be more favourable to the population’s overall health. It may be striking for example how sun exposure may actually reduce the chance of many cancers significantly.
The importance of sunlight may be highlighted by the amount and intensity of sunlight a location receives. In countries below a certain latitude with a greater intensity and day length, there may be a much smaller incidence of many cancers. The distance away from the equator also influences the proportion of coronary conditions, which appear to be independent of other factors like diet and activity levels. Higher cholesterol levels are seen in latitudes further away from the equator and this may be a necessary contributor.
It has been recognised how exposure to sunlight may photosynthesise cholesterol to produce vitamin D, which may explain the sunlight and cholesterol link. During observations of those exhibiting high levels of outdoor activity, cholesterol levels significantly decreased during summer. The effects of sunlight on cholesterol may be further demonstrated by levels being higher during winter. This demonstrates how the advantages of sun ray absorption are an exclusive product of sunlight, being independent of activity and diet.
Vitamin D also supports the absorption of many other minerals including calcium which is essential for bone health. This may be visible in individuals below certain latitudes having far greater bone health and fewer osteoporosis cases. It additionally influences and regulates the immune system, which may be clearly seen in auto-immune skin conditions like psoriasis which are improved by sunlight. In fact, doctors used to advise sunbathing to treat a range of conditions including rickets in the 1600s and tuberculosis.
The length of sun exposure may be important in gaining its health benefits. Short periods of time in the sun are seen as more beneficial, longer periods have decreased benefits and greater effects on the skin. This may be because vitamin D rises to certain levels after which natural feedback loops within the human physiology halt further production. This mechanism may prevent the vitamin accumulating in high concentrations, and may explain why short periods of sun exposure are far more beneficial to the health.
Exposure length might be an essential consideration depending on whether an individual has light skin or dark skin. White skin evolved in Europe where UVA and UVB intensity is limited in comparison to the equator latitudes, where the black skin of Africans may be far more resistant to sunlight. This means white skin needs limited exposure to release the same amount of vitamin d into the circulation. This may be relevant for individuals with white skin living in countries with higher UVA and UVB levels or black skinned individuals living in countries with a moderate sunlight intensity.
Sun exposure may lead to many health advantages. It may stimulate the immune system, improve cardiovascular health and alleviate diabetes. Many of these improvements may be explained by the role of cholesterol and vitamin D which both derive from the same zoosterol. Vitamin D and nitric oxide act as hormones and steroids which are essential for cardiovascular health, attaching to receptors of the heart and muscle cells having a relaxing effect. It may now be clear from the accumulation of research how sunlight simultaneously reduces cholesterol and increases vitamin D levels. The effects of the sun may be productive even in individuals with skin melanoma, displaying higher rates of survival when continuing high levels of sun exposure. Present beliefs about sun exposure may need to change for the benefit of all countries’ health.
How does sun exposure lead to improved health?