A recent study by researchers at the University of Liverpool compared the application efficacy between traditional sunscreens and moisturizers with SPF.
It is well known that ultraviolet (UV) radiation exposure has several harmful effects, such as premature aging and skin cancer. However, despite the wide promotion of the use of products containing sun protection factor (SPF), incidences of both melanoma and non-melanoma skin cancer are on the rise.
Moisturizers with SPF were developed in the hope that they would be used more regularly than traditional sunscreens, as sunscreens were mostly only used when people were expecting a higher-than-average sun exposure.
Concerns regarding the incorrect applications of moisturizers with SPF
When moisturizers with SPF were first released into the market, their SPF rating was limited to lower levels, but many popular brands now offer products with SPF ratings equivalent to those of traditional sunscreens (SPF 30-50).
Despite the higher chance of application of moisturizers with SPF, there is some concern that people would not apply them correctly and this would lead them to underestimate their exposure to damaging UV radiation.
The eye region has the highest rates of skin cancer
This concern is based on previous studies that demonstrated that, when applying sunscreens, people tended to neglect their eyelid regions. Studies indicate that the eyelids and the regions around the eye have high incidence rates of skin cancer. However, there are very few studies evaluating the use of moisturizers with SPF and comparing its efficacy with conventional sunscreens.Â
Researchers at the University of Liverpool assessed whether users of moisturizers with SPF also sufficiently cover the vulnerable area around their eyes. This study analyzed the way people applied a sunscreen lotion and a moisturizer with SPF and how this affected the level of protection against UV radiation. This study was published in the journal PLOS ONE.
How effective are applications using sunscreen vs. moisturizers with SPF?Â
The study included 84 participants, 22 men and 62 women, that were 18-57 years old. The sunscreen and moisturizer with SPF tested were advertised as SPF30 and had the same primary active ingredient, titanium dioxide. Although both products were, according to the instructions of use, suitable for application to the face in general, they recommend avoiding the eyes.
During the first visit, the participants were asked to complete a pre-study questionnaire and were exposed to UV radiation and photographed using a UV-sensitive camera before and after applying either SPF30 sunscreen or moisturizer. In the second visit, the imaging procedure was repeated with the other formulation and a post-study questionnaire was carried out.Â
People tend to apply sunscreens more thoroughly than moisturizers with SPF
Notably, the researchers found that when the participants applied sunscreen, 11.1% of the total face area was not covered and 16.6% was missed when applying SPF moisturizer. The regions that were most often neglected where, indeed, the eyelids and the areas around the eyes. The participants of the study reported being unaware of their incomplete coverage and of the different way they applied the sunscreen and the moisturizer with SPF.
Also, the results indicated that the participants seemed to use a lower amount of the moisturizer with SPF than of the sunscreen, leading to an overall lower level of protection to UV radiation when using the moisturizer with SPF despite the fact that the formulation of both products was deemed nearly equally effective.
The researchers suggested that this difference in the application could be due to the fact that the moisturizer with SPF had a higher viscosity, and was thus harder to spread, than the sunscreen. However, they do not discard other possible explanations, such as the influence of the different size of product containers in user behaviour.
Face areas that are more vulnerable to skin cancer are more often neglected with the use of moisturizers with SPF
To conclude, the authors stated that their study “demonstrates that areas of the face that are more vulnerable to skin cancer are also more likely to be missed during application of SPF moisturizers that with sunscreens, and, importantly, that people applying these products are unaware that they are failing to cover these at-risk regions.”
Although short-term UV exposure is recommended due to numerous health benefits (vitamin D production, mood improvement, etc), people tend to expose themselves to long periods of UV radiation when wearing SPF containing products. Therefore, consistently unprotected areas are likely to accumulate UV-related damage at a higher level than more protected areas.
Finally, the researchers emphasize that public education on protection against UV damage should focus on protecting the vulnerable areas around the eyelids.
Written by Maria Isabel Acosta Lopez, PhD, Medical Writer
References:
- Lourenco, E. A. J., Shaw, L., Pratt, H., Duffy, G. L., Czanner, G., Zheng, Y., et al. (2019). Application of SPF moisturisers is inferior to sunscreens in coverage of facial and eyelid regions. PLoS ONE, 14(4), e0212548. http://doi.org/10.1371/journal.pone.0212548
-  IOS Press. (2019, February 21). Sunscreen application has better face coverage than SPF moisturizers. EurekAlert! Retrieved April 9, 2019 from https://www.eurekalert.org/pub_releases/2019-04/p-sah032719.php
