If you pay attention to the health and wellness discussions in the media you may have noticed a general paranoia regarding the effects of the sun on the skin. While I am generally skeptical of the ever changing trends on what is "healthy" the evidence seems overwhelming that sun exposure is very damaging for the skin. On the flip side, there are discussions about an epidemic of Vitamin D deficiency in the US due to a lack of sun exposure. So what is going on here? In my common sense mind it seems that we humans have been living under the sun for millenia so just how bad could it be?
Who doesn't love a sunny day? But can too much of a good thing have long lasting and severe consequences?
UV Alphabet
There are numerous types of Ultraviolet (UV) rays but the two that we need to worry about are UVA and UVB. UVB rays are responsible for the immediate skin damage that we see in the form of sunburn. The UVA rays have longer term effects such as accelerated aging, immune suppression and various skin cancers. It is important to remember that more UV rays make it through the atmosphere when the sun is higher in the sky meaning that we have much greater exposure in the hours between 10a-4p. Finally, while UVB rays are seasonal, being much stronger in the summer than in the winter, the amount of UVA rays which hit the earth does not fluctuate nearly as much. This means you need to think about your sun exposure and long term skin health all year. Now that we have a basic understanding of the sun's UV rays and how they interact with the earth and our skin lets look at the specific effects on us.
The Good
While most essential vitamins must be obtained though our diet, Vitamin D can actually be produced by our bodies when exposed to the suns UVB rays. Depending on skin pigmentation, 30 minutes spent in the sun in a bathing suit will result in the body producing between 10,000 and 50,000 IU of vitamin D. Lighter skinned individuals will be on the higher end of the scale as lighter skin is more effective at synthesizing the vitamin than skin with darker pigmentation. Vitamin D enhances calcium and phosphorus absorption, controlling the flow of calcium into and out of bones to regulate bone-calcium metabolism, making vitamin d critical for bone formation and continued bone health. It also assists with the regulating the immune system and recent research has indicated that it may be related to deterring cancer, minimizing the frequency and severity of asthma, minimizing the likelihood of multiple sclerosis, maintaining healthy brain activity and regulating body weight.
Another benefit of sun exposure is relief from SAD or seasonal affective disorder which is a mood disorder in which people who have normal mental health throughout the year display depressive symptoms in certain seasons of the year. Regular exposure to sunlight, also called light therapy, has been a reliable treatment for SAD in its classic winter-time form.
The Bad
Now that we've covered the benefits of limited sun exposure let's look at the negative side effects of excessive exposure. Most folks don't realize that even a nice golden tan is actually the result of sun damage to the epidermis, which leads us to the first effect of sun exposure, accelerated aging. The cumulative effects of tans and burns result in accelerated aging in the form of early wrinkling and age spots or actinic keratoses. Actinic keratoses is a rough scaly patch that develops on your skin due to prolonged sun exposure. These spots are usually found on the face, lips, ears, back of your hands, forearms, scalp or neck. These spots generally grow slowly over time but should be monitored as they are frequently considered precancerous.
An image of melanoma
The most adverse effects of prolonged sun exposure is skin cancer, which is the most prevalent cancer in the US. 95% of all skin cancers are either Basal cell or squamous cell cancers and are highly curable when treated early. The third type of skin cancer, melanoma, is much more serious. Melanoma is made up of cells called melanocytes, which are abnormal skin pigment cells. If left untreated Melanoma can spread to other organs which is why it accounts for 75% of all skin cancer deaths.
A final effect of excessive sun exposure is the adverse affect it can have on the immune system. While normal or slightly elevated sun exposure may adversely affect the skins ability to resist viral attacks excessive sun exposure has been associated with systemic (whole body) immunosuppression.
What Now?
So what is to be done? How do we get sufficient Vitamin D while not looking twice our age and developing cancer? Here are a few tips that should help.
- Use sunscreen with a minimum SPF of 15 and apply it 15 to 30 minutes before sun exposure. Reapply every few hours.
- Avoid being in the sun between 10am and 4pm when the UV exposure is most intense
- Wear tightly woven clothing and a wide brimmed hat
- Wear sunglasses that provide full UV protection
- 80% of a person's lifetime sun exposure is acquired before age 18. Start these practices with your child at an early age.
The affects of sun exposure are much more severe for young children, even infants.
Up Next! Now the I've decided I need to go invest in some sunscreen, how do I know what to choose? In the next issue of Dermis Love, we delve into the complexities of sunscreen. What is it? What does SPF stand for? Can it be achieved by natural means?
Disclaimer:Ok, so we are not doctors. None of the statements have been vetted by the FDA or any other government or regulatory agency. We strongly recommend that you discuss your skin health with your physician.
Sources:
National Center for Biotechnology Information