Sunscreen use benefit and risks, retardation of skin aging by Ray Sahelian, M.D.
February 17 2016

Too much of the sun's ultraviolet radiation will turn your skin into a crinkly patch of leather and up your cancer risk. Sunscreen (also known as sunblock, suncream, suntan lotion) is a lotion, cream, spray or other topical product that may help protect the skin from the sun's ultraviolet radiation, and which reduces sunburn, wrinkles, and other skin damage, ultimately leading to a lower risk of skin cancer. However, in regards to skin health, even the best sunscreens are not as good as wearing a hat and long sleeved shirt and thus providing complete blockage of the sun's rays. Some form of sun exposure is needed for the skin to make vitamin D. Therefore, there has to be a good balance between sun protection and sun exposure.
   Sunlight contains the visible light that we can see and ultraviolet (UV) light that we cannot. There are two types of UV light, UVA and UVB. UVA light is responsible for tanning and UVB for sunburn. Both can damage the skin and increase the risk of skin cancer. SPF ratings on sunscreens refer only to UVB protection, not UVA protection. Sunless tanning lotions lead women to skip sunbathing.

Sunburn in Early Life Raises Skin Cancer Risk by a significant amount.

Natural sunburn protection, do vitamins help?
Many people claim that astaxanthin supplement helps prevent or reduce sunburn.

Are sunscreens effective?
Sunscreens have been marketed as an important part of total sun protection strategy as consumers arm themselves against the harmful sun rays. However, sunscreens provide only partial protection from harmful UVA and UVB rays, in addition to using a sunscreen, consumers protect themselves from sun exposure by limiting time in the sun and wearing protective clothing.
   Sunscreens may actually be not as protective from sun rays as previously thought. Sunscreens may be promising more than the can deliver. Most of the sunscreens on the market partially protect from Ultraviolet B radiation, but much less from UVA radiation. UVB radiation causes sunburn. UVA radiation penetrates deeper into the skin and can increase the risk of skin cancer and the skin to age.
   Even though sunscreens have been shown to mostly protect against UV skin damage as well as basal carcinomas and squamous cell carcinoma — two of the three most common skin cancers -- they have not been conclusively shown to protect against melanoma , the most fatal kind. Protective clothing and a hat are your best options to prevent sun induced skin cancer.

Vitamin D absorption, is there any interference?
Adv Exp Med Biol. 2014. Sunscreens. Bens G. Cutaneous vitamin D synthesis depending on skin-carcinogenic UVB radiation, the potential risk of vitamin D deficiency by sunscreen use has become a major subject of public health debate. Sunscreens indeed impair vitamin D synthesis if they are used in the recommended amount of 2 mg/cm2, but not in lesser thickness below 1.5 mg/cm2 that corresponds better to what users apply in real life conditions.

Slowing skin aging
Ann Intern Med. 2013. Sunscreen and prevention of skin aging: a randomized trial. Regular sunscreen use retards skin aging in healthy, middle-aged men and women. No overall effect of β-carotene on skin aging was identified, and further study is required to definitively exclude potential benefit or potential harm.

SPF number and Sunscreen Efficacy

Sun protection factor (SPF) is a rating given to sunscreens to help gauge the amount of protection they provide against the sun's damaging UV rays. Sun Protection Factor refers only to UVB radiation, not to UVA radiation. The FDA has no standards for measuring UVA protection by a sunscreen.

   An SPF of 15 means you'll have 15 times the amount of protection from the sun that you normally would without any sunscreen. That means spending 15 minutes in the sun with SPF 15 applied is the equivalent of spending roughly 1 minute in the sun without any sunscreen. Sunscreen with an SPF of 15 or higher is recommended for anyone, especially children. Sunscreens that protect against both UVA and UVB rays offer the most benefit. However, it may not be as simple as it seems, we are now finding out that there is not as clear a linear relationship between the number of the sunscreen tube and the protection you may get. Although using sunscreen helps, there is nothing better than complete coverage of the skin with clothing or a wide brimmed hat if you plan to be under the midday sun for prolonged periods.

In 2011 FDA announced those sunscreen products that pass the FDA's test for protection against both ultraviolet A (UVA) and ultraviolet B (UVB) rays will be labeled as "Broad Spectrum". Only products labeled as "Broad Spectrum" with 15 SPF or higher will now be able to state on their labels that they reduce the risk of skin cancer and early skin aging, when used as directed. Products not in this range will require a warning label stating that the product has NOT been shown to prevent skin cancer or early skin aging.

May 17, 2016 -- More than 40% of sunscreens tested by Consumer Reports experts don't live up to their SPF claims, according to the organization's annual report on the products.

Exposure to UVA and UVB rays is always harmful. The damage from these UV rays may be obvious right away in the form of a tan or sunburn, but they can lead a range of problems, from wrinkles to skin cancer. Choosing a sunscreen from the wide array of lotions and sprays with various ingredients may be confusing. Most sunscreens on the market offer broad spectrum protection from both UVA and UVB rays, but SPF values can range widely, from 2 to 100.The SPF number indicates how many more minutes the sunscreen will allow someone to remain in the sun without getting burned than if they had no protection on their skin.

Sunscreen claims

The claims on sunscreen bottles that they protect radiation all day, or are sweatproof or waterproof, may be misleading. Sunscreen labels may give people a false sense of security, thinking that they can safely stay in the sun for hours and not have skin damage as long as they apply a coat of sunscreen on their skin. 

Regulations by FDA
2007 - The FDA is recommending a four-star rating system for sunscreen protection against UVA light, along with a warning that stresses the importance of not relying solely on sunscreens to prevent skin cancer and skin damage. One star would represent low UVA protection, two stars would represent medium protection, three stars would represent high protection, and four stars would represent the highest UVA protection available in an over-the-counter sunscreen product. A sunscreen that currently says "SPF 45" would say "UVB SPF 45" with the word "high" to indicate a high level of UVB protection.
   The FDA also proposes requiring all sunscreens to include a "Warnings" statement in the "Drug Facts" box. The warning would say: "UV exposure from the sun increases the risk of skin cancer, premature skin aging, and other skin damage. It is important to decrease UV exposure by limiting time in the sun, wearing protective clothing, and using a sunscreen." The warning is intended to increase awareness that sunscreens are only one part of a sun protection program.
 

Sunscreens and Skin Cancer
Lawsuits filed in 2006 accuse sunscreen makers of exposing millions of people to skin cancer and other dangers through false and misleading claims about the effectiveness of their sunscreen skin care products. The nine suits - involving some of the most popular brands, including Coppertone, Banana Boat, Hawaiian Tropic, Bullfrog and Neutrogena - charge that manufacturers dangerously inflate claims about the protective qualities of sunscreens, lulling consumers into believing they are safe from the dangers of prolonged skin exposure to sun. Ultraviolet radiation from the sun is the leading cause of skin cancer. The suits, filed in California, name as defendants Johnson & Johnson Inc., Schering-Plough Corp., Playtex Products Inc., Tanning Research Laboratories Inc. and Chattem Inc. The suits focus on labels that claim the sunscreens protect equally against the sun's harmful UVA and UVB rays, and also claims of how long supposed waterproof sunscreen remains effective in water. "In truth and in fact ... as defendants knew or should have known, their skin protection products, at best, only protect the skin against harmful UVA rays with shorter wavelengths, while the skin remains exposed to harmful UVA rays with longer wavelengths that penetrate deep within the skin," according to the suits.

Anthelios SX Sunscreen by LaRoche-Posay

Anthelios SX is a sunscreen from L'Oreal to be sold over-the-counter (OTC) for the prevention of sunburn and for protection against ultraviolet B (UVB) and ultraviolet A (UVA) rays. It has a sun protection factor (SPF) of 15. Anthelios SX is a sunscreen product that contains a combination of three active ingredients. One of the ingredients is a new molecular entity (NME), ecamsule. Ecamsule has not been marketed in the United States, but has been marketed in Europe and Canada as Mexoryl SX since 1993. The other two active ingredients, avobenzone and octocrylene, are generally recognized as safe and effective under the current OTC monograph for sunscreens. Side effects of Anthelios SX reported during clinical studies were acne, dermatitis, dry skin, eczema, abnormal redness, itching, skin discomfort and sunburn. Anthelios SX is distributed by LaRoche-Posay. Time will tell whether Anthellos helps reduce the risk for skn cancer or wrinkles.

Medical Resources
Craig Eichler, M.D., board-certified dermatologist, says, " Not all sunscreen ingredients are created equal -- some provide minimal protection against ultraviolet A (UVA) radiation, which can cause skin cancer and wrinkles. UVA is not considered in the sun-protection factor (SPF). SPF refers to protection against UVB radiation, a different wavelength that can also cause skin cancer, plus sunburn. To best protect their skin, it's important for consumers to recognize the names of the most effective ingredients, and also understand the differences between SPF levels and terminology like water-proof or water resistant." Craig Eichler, M.D., is a fellow of the American Academy of Dermatology.

Contact Dermatitis. February 2014. Allergic contact cheilitis caused by polysilicone-15 (Parsol® SLX) in a lipcare balm.

Tanning salons
American teens who indulge in indoor tanning -- long linked to skin cancer risk -- are also more likely to adopt other bad habits. Indoor tanning is associated with a number of other risky behaviors, such as illegal drug use, binge drinking and smoking, according to study lead author Gery Guy Jr., New York University Medical Center, New York City; Feb. 26, 2014, JAMA Dermatology, online.

Questions
Are steroid creams helpful for sunburns?
   Corticosteroid creams and ointments are often recommended for soothing a sunburn, but they do not offer much help.

There is a recent phobia of natural sunshine. I have been enjoying the sun all my life, i even heard opinions that a certain level of UV light is healthy and natural to the body. Again, skin cancer did not seem to be such wide-spread as today. Maybe it was just less publicized, but it really appeared that people having a healthy amount of time out on the sun were healthier, stronger, happier and better looking. Nowadays i also use SPF creams but i almost find that the more i use them, the less my skin's ability is to tan healthy when i do not use the creams, and i have more skin spots appear than when i was using nothing. Has the sun changed so much? Am i just seeing the ageing process on skin exposed to the sun? What is your take on the issue?
   Most people are not getting enough sun exposure and not getting enough vitamin D as a result. There is no reason for most people to use sunscreen if they are outdoors less than an hour a day.