By Sarah McNeillPublished June 11, 2018 06:06:57Scientists from the University of Ottawa, the University de Montréal and the University College London have discovered a way to prevent sunburn by protecting against the damaging effects of UVB rays.
The team of researchers tested the effects of sunscreen, the first to show any promise for sun protection, on human skin in two different ways: one when it was applied before a night out and another when it is applied after.
The results were published online today (June 10) in the Journal of the Royal Society Interface.
“When people get out of bed after getting up from the toilet, they often don’t feel good about themselves and the effects on their skin can be harmful,” said senior author Professor John Tarnopolsky, an assistant professor in the University’s School of Public Health.
“It is important to know what’s in sunscreen so we can make changes to help protect ourselves.”
The research found that when sunscreen is applied before going to bed, it increases the risk of skin cancer.
“A lot of research is being done to develop effective sunscreen for preventing sunburn and we need to be cautious when applying sunscreen to the skin,” Professor Tarnovsky said.
“Our research shows that sunscreen applied before sleep, even after getting out of the shower, increases the levels of the reactive oxygen species in the skin, which increase the likelihood of skin cell damage.”
The researchers found that after applying sunscreen, it was as effective as a standard sunscreen to protect against the effects UVB exposure, but it was only effective at reducing UVB damage.
The researchers say the results suggest the use of sunscreen before bed is safe, but there is still much to be done.
“We need to understand more about what’s going on in the human body,” said co-author Professor Michael Gagnon, also from the School of Health Sciences.
“Understanding how the sun affects our health could provide important clues to how to develop new sunscreens that protect against UVB, but we also need to learn more about the skin cells in our skin that can be damaged by the UVB.”
Sunscreen is a product used to protect the skin from UVB radiation, which is a type of radiation that can damage DNA and cause sunburn.
The research team studied human skin cells from different parts of the body, including the eye, liver, brain, pancreas, lung and kidneys.
“The most striking result was that when the sun was applied prior to bedtime, it significantly increased the levels and activity of the ROS-dependent transcription factor c-Jun N-terminal kinase (JNK), which is involved in the initiation of DNA damage in skin cells,” Professor Gagn on the Universitys Department of Biochemistry and Molecular Biology said.
Sunscreen application after a night of sleeping and before bed increased levels of ROS-positive cells, which are more reactive to UVB.
“These results demonstrate that UVB is a major contributor to UV-induced skin damage in humans and that this process can be stopped by sunscreen application before sleep,” Professor David Oakes said.
This research is a collaboration between the University, the U of O, the Université du Québec à Montréala and the Universite de Montéréal.
The work was supported by the Department of Health Research, the Canadian Institutes of Health Services, and the Canadian Cancer Society.