New Delhi: A new study reveals that sitting under an umbrella while at the beach to protect from the sun may not be as effective as you first think , quashing a common belief that umbrella may be a substitute for sunscreen.
To determine the intensity sun protection provided by a standard beach umbrella versus a sunscreen with an SPF of 100, researchers recruited 81 fair-skinned people in the study.
All 81 participants were made to sit in the midday sun at Lake Lewisville, Texas, for 3.5 hours in August 2014. The participants were randomly assigned to use SPF 100 sunscreen or to use a standard-size beach umbrella.
The participants were then checked the next day for sunburns.
The researchers found about 78 percent of people who used only an umbrella to protect themselves from the sun during a few hours at the beach were sunburned the next day, compared to only 25 percent of people who used sunscreen with a sun protection factor (SPF) of 100.
They found 142 sunburned areas on the 41 people who used an umbrella, but only 17 on those who used sunscreen.
But while sunscreen prevented more sunburns than a large umbrella, neither method was 100 percent effective. "It’s good to have a holistic approach," said lead author Dr Hao Ou-Yang. "You need to think of a combination of measures."
Ou-Yang and a coauthor both work for Johnson and Johnson Consumer Inc. in Skillman, New Jersey. The company partly funded the study and is the parent company of Neutrogena Corp, which manufactures the sunscreen used in the research.
Ou-Yang said that people should use a combination of approaches like using a high-SPF sunscreen, wearing clothes and a hat and seeking shade.
Overall, 32 of those who used umbrellas ended up with sunburns, compared to 10 in the sunscreen group.
"You don’t want to just trust one method for sun protection," said Dr. Jennifer Stein, a dermatologist at NYU Langone Medical Center in New York City.
"The safest way to be outside is avoid the middle of the day, sit in the shade, wear protective clothing and sunscreen."
Stein, who was not involved with the new study, added that people should use a sunscreen with an SPF of at least 30.
Using a combination of protective factors can prevent sunburns even among people with the fairest skin, she said.
While beach umbrellas are designed to block direct rays from the sun, they don't protect against scattered rays, researchers explained.
The study has been published in JAMA Dermatology.
