Ultraviolet ray from sun exposure has been known as the main cause of skin cancers. However, sun exposure is vital for the production of vitamin D, which in turns protects against internal cancers and a number of other diseases. So the dilemma exists, should we increase or reduce our daily sun exposure? To make the right decision, we should know the pros and cons of it.
The benefits of sun exposure
Sun exposure helps our body produce vitamin D as very few foods in nature contain this vitamin. Vitamin D can be found in the flesh of fatty fish such as salmon, tuna, and mackerel as well as fish liver oils. Small amounts of vitamin D are found in beef liver, cheese, and egg yolks while mushrooms provide vitamin D in variable amounts. Vitamin D facilitates the absorption of calcium and phosphate which are important for healthy bones, teeth and muscles. Adequate vitamin D prevents a number of diseases, including cancers, heart disease and autoimmune disease.
In a review of studies done in 2014, breast cancer patients with high level of vitamin D (more than 32ng/mL) at the time of diagnosis had approximately half the death rate from breast cancer compare with those with a low level of vitamin D (less than 14ng/mL). Colorectal cancer, prostate cancer, bladder cancer and Non-Hodgkin Lymphoma are also reported to benefit from sun exposure.
Sun exposure is also associated with a reduction of hypertension by UV rays-induced nitric oxide. It is known that the nitrogen oxides found in the human skin will be mobilized to the blood circulation by exposing the body to UVA radiation. Nitric oxide is known as a blood vessel relaxation agent which results in a decrease in blood pressure.
Besides vitamin D and nitric oxide, sun exposure is known to promote the production of melatonin, serotonin and the regulation of the circadian clock, which is our biological clock. This, in turn, will promote better sleep and emotional well being.
The adverse effects of sun exposure
The adverse effects of sunlight include the development of skin cancer and degenerative changes in the skin. Women who had five or more blistering sunburns between the ages of 15 and 20, compared to those that had none, are likely to possess a higher risk of melanoma, the most aggressive form of skin cancer by 80%. Melanoma is a skin cancer that arises from the melanocytes, the cells that control skin pigmentation. Besides possible genetic factor, ultraviolet radiation from sun exposure can induce its formation. Other skin cancers such as squamous cell carcinoma and basal cell carcinoma may also be associated with sun over-exposure.
Should I limit or increase sun exposure?
Skin cancers and degenerative changes of the skin may hesitate you from exposing yourself to the sun. But the relationship between melanoma and ultraviolet ray is two-sided. Non-burning sun exposure is associated with a reduced risk of melanoma, while sunburns are associated with a double risk of melanoma. In fact, it has long been observed that outdoor workers have a lower incidence of melanoma than indoor workers.
Hence, moderation is an important key to sun exposure. Without adequate sun exposure, you will deprive your body of its benefits while exposing yourself to the risk of vitamin D deficiency. All you need to do is to take the right measure when exposing yourself in the sun. Use sunscreen to protect against the ultraviolet ray and moisturize your skin adequately to prevent degenerative damage to sun exposure.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Review Date: November 15, 2018 | Last Modified: November 15, 2018
David G. Hoel et al., ‘The Risks and Benefits of Sun Exposure 2016’, Dermato-Endocrinology 8, no. 1 (December 2016): e1248325, https://doi.org/10.1080/19381980.2016.1248325.
Johan Moan et al., ‘Addressing the Health Benefits and Risks, Involving Vitamin D or Skin Cancer, of Increased Sun Exposure’, Proceedings of the National Academy of Sciences 105, no. 2 (15 January 2008): 668–73, https://doi.org/10.1073/pnas.0710615105.
J. van der Rhee, E. de Vries, and J. W. W. Coebergh, ‘[Favourable and unfavourable effects of exposure to sunlight]’, Nederlands Tijdschrift Voor Geneeskunde 151, no. 2 (13 January 2007): 118–22.