Above: Image © istockphoto.com/shironosov
Did you know? In British Columbia, teens under the age of 18 have been banned from using tanning beds in the hopes of limiting their chances of developing skin cancer. Most people know that UV exposure is a risk factor for skin cancer. In the United States alone, over 9500 people die from melanoma each year and 86% of these cases can be directly attributed to UV exposure. Yet tanning remains a very popular activity among young adults. Even when people know tanning is bad for their health, they still seem drawn to it in much the same way as addictive drugs.
Varieties of UV light
UV light comes in three varieties: UVA, UVB, UVC:
UVC rays are the most damaging, but they are completely absorbed by the ozone layer and atmosphere. UVB rays are mostly absorbed by the ozone layer, but some do get through. They cause sunburns and darkening of the skin when you tan. UVA rays account for most of the UV light that reaches the Earth’s surface. Along with tanning, UVA rays cause premature aging by degrading collagen, which is important for skin’s elasticity, and by damaging skin on a molecular level, leading to wrinkles.
Both UVA and UVB rays have been linked to the development of cancer. And indoor tanning is not a safe alternative. You will be exposed to both types of UV light whether you tan indoors or out.
So is tanning addictive? The Center for Addiction and Mental Health defines addiction in terms of the “4 C’s”:
craving loss of control over the amount or frequency of use compulsive use continuing use despite consequences
Did you know? There is no such thing as a healthy tan. All UV light, including rays from indoor tanning equipment, is carcinogenic.Most people who chronically tan probably display at least one of these behaviours. Furthermore, studies have shown that that chronic tanners show withdrawal symptoms similar to those experienced by drug users. These include anxiety, restlessness, headaches, and depression.
One study published in 2014 shows that mice exposed to UVB light had increased levels of a certain endorphin in their blood and displayed addictive behaviors, including withdrawal symptoms. Endorphins are natural painkillers that are released during periods of stress. They are also responsible for the rush people feel when they exercise or get scared. Drugs such as morphine have similar effects to endorphins and are known to be addictive.
So why would a dangerous behaviour like tanning be addictive? After all, the mice were exposed to a relatively small amount of light: the equivalent of 20-30 minutes of sun in a Florida summer. There must be some biological advantage to sun exposure for it to induce addictive sun-seeking tendencies.
Researchers suggest that the impulse to tan may be related to dietary requirements. Sun exposure is necessary for the production of vitamin D in humans. It would therefore be beneficial for moderate sun exposure to stimulate the brain’s reward system. However, since most people now receive supplemental vitamin D in milk and other foods, the natural mechanism causing them to crave sun exposure has become unnecessary.
Did you know? UV light is dangerous because it damages the DNA inside skin cells. UV light is full of energy and causes the bonds in DNA to break or to form in the wrong places.But for some people who continue to tan for fashion, carvings appear to hijack the brain’s reward mechanism, resulting in addiction-like behaviour. In light of the research conducted so far, it may be beneficial to treat chronic tanners with the same techniques developed for other addictive behaviours, such as early prevention and behavioural interventions.
So while sun exposure produces nutrients and lifts your spirits, it is important to protect yourself from the dangers of UV light. Wearing sunscreen and avoiding tanning beds can help you remain healthy by avoiding both sunburns and skin cancer.
Skin Cancer Facts (2014)
US Skin Cancer Foundation
Extensive information on skin cancer causes and prevention, with references.
Ultraviolet Radiation (2013)
Canadian Centre for Occupational Health and Safety (2013)
An introduction to ultraviolet radiation, with information on its effects on the eyes and the skin, on sources of exposure, and on how to limit exposure.
UV Radiation (2013)
US Environmental Protection Agency
An introduction to UV radiation, including a discussion of factors that affect UV levels.
Indoor Tanning: The Risks of Ultraviolet Rays (2010)
US Food and Drug Administration
Consumer and medical information on the risks associated with indoor tanning.
Understanding UVA and UVB (2013)
US Skin Cancer Foundation
An introduction to UVA and UVB rays and their effects on the human body.
Side effects of naltrexone observed in frequent tanners: Could frequent tanners have ultraviolet-induced high opioid levels? (2005)
Mandeep Kaur, Anthony Liguori, Alan B. Fleischer Jr., and Steven R. Feldman, Journal of the American Academy of Dermatology 52(5), 916
A letter from medical researchers on the possible causes of and potential treatments for compulsive tanning.
Vitamin D and your health: Breaking old rules, raising new hopes (2007)
Harvard Health Publications, Harvard Medical School
An article discussing the sources and benefits of vitamin D.
Tanning Addition: The New Form of Substance Abuse (2010)
Robin L. Hornung and Solmaz Poorsattar, US Skin Cancer Foundation
An article discussing research into tanning addition and surrounding issues, with references.
G. L. Fell, K. C. Robinson, J. Mao, C. J. Woolf and D. E. Fisher.
Skin β-endorphin mediates addiction to UV light. (2014). Cell 157(7),1527-1534.
An article describing experiments related to UV exposure and endorphin production performed on rodents and discussing possible implications for UV addiction and its treatment in humans. A summary of the article is available on the publisher’s website. However, a subscription is required to view the full text.