Healthy Living

Using Sunscreen Does Not Guarantee Full Protection

Sometimes, using sunscreen might not guarantee full protection from the sun's harmful rays. Learn more.

Using Sunscreen Does Not Guarantee Full Protection

According to a new study, people who apply sunscreen regularly and vigilantly may have more painful and damaging sunburns. In this study, the researchers collected data regarding the different methods of shielding the sun, and the effectiveness of each of these methods. Data was collected from more than 3,000 participants in the National Health and Nutrition Examination Survey. The most commonly used protection method was more than 30% people wearing sunscreen to protect their skin if they were outside for more than an hour. The other common method of protecting from the sun include being in the shade (25%), wearing hats (16%), and wearing long sleeves (6%). The results of the study were published in the journal Cancer, Causes, and Control.

The results showed that people who used sunscreen had 23% higher risk of sunburns in the last year, when compared to those who rarely used sunscreen as a method to protect the skin. The increased risk was seen even after accounting for all other factors that increases the chances of sunburn, like sensitivity to the sun, alcohol use, season, physical activity, age, gender, education, and income. Those who preferred to be in the shade had a 30% lower risk of sunburns, when compared to those who rarely used the measure.


Ronald P. Rapini, MD, professor and chairman of the department of dermatology at the University of Texas M.D. Anderson Cancer Center in Houston, liked the study, as she always felt that applying sunscreen was not the ideal method to protect the skin. Rapini uses the example a patient who dared to be in the sun for a long time thinking that it is safe after using sunscreen, but was later diagnosed with melanoma on the patient's where sunscreen was not applied. “Wearing sunscreen gives a false sense of security and people tend to overlook that it does not cover the skin too well”, warns Rapini.

According to study researcher Eleni Linos, MD, DrPH, MPH, a dermatologist at Stanford University, the associations found with different types of sun protection methods are really surprising. The results clearly show that wearing a hat, or donning a long-sleeved dress, and being in the shade are associated with less sunburn, while wearing sunscreen was associated with more sunburns. Linos points out that the study does not mean that sunscreen is not effective in protecting the skin or that it should not be used. “The study basically looked at the patterns and did not look at the cause and effect relationship”, she adds.

According to her, it is possible that people with fair skin who are have a higher chance of getting a sunburn might be the group who are most likely to use sunscreen. But if it was true, the same must have been true with all the different groups and frequent shade seekers would also have more burns compared to those who do not use the strategy. The most likely explanation may be user error, as people may not be using as much sunscreen as recommended for them.

In one of the studies conducted in Brazil, the participants were asked to cover the forearms with sunscreen and 30 minutes later they were asked to reapply the sunscreen in one of the arms. Tape strips were used to measure how thickly the lotion went on. Sunscreen lotions work best when it is applied to a depth of at least 2 milligrams per square centimeter on the skin. The results of the study show that after the first application, the participants got only one quarter of that amount. The other arm where a second application was done had about half of the recommended thickness. This showed that people who remembered to reapply the sunscreen are also not fully protected.

Many people consider using sunscreen as the sole protection against the sun, and forget about protective clothing or being in the shade, which are equally important in avoiding sunburn. Henry W. Lim, MD, chair of the department of dermatology at Henry Ford Health System in Detroit, feels that a lot of studies have to be done to educate the people about proper photoreception. Lim says that although people use sunscreen, they may not use at the appropriate levels for protection. The false sense of security that sunscreen will provide the needed protection can lead them to stay longer in the sun than they safely should, which can result in sunburns and skin cancer.

According to a study conducted on 1,621 people in Australia, the use of sunscreen reduces the risk of melanoma by 50%. The participants in this study carefully reapplied the sunscreen, wore long sleeved shirts, and remained in the shade whenever possible. Darrell S. Rigel, MD, a clinical professor of dermatology at New York University, says that the best combination for protection from the sun is to be in the shade wearing a long-sleeved dress and lots of sunscreen. Rigel warns that the sunscreens have improved a lot in the key needs. For example, the substantivity of the products has increased and many new products offer protection against both UV A and UV B rays.