Teenagers who spend more than six hours a day watching television or a computer may be more likely to enter puberty earlier than those who spend less time in front of a screen, a study suggests.
Experts from Turkey’s Gazi University exposed rats to six hours of blue light (emitted from screens) or 12 hours, and found that six was enough to accelerate growth.
This triggered puberty earlier than another group exposed to the same amount of natural light.
Presenting their findings at a conference in Liverpool, the team admitted that their findings were limited to animals; However, they said the research could be used to inform “preventive measures for safe screen use” in children.
It comes as experts identify an intriguing trend of increasing numbers of girls starting their menstrual cycles earlier than historical averages.
Research shows there was a staggering 52 per cent increase in children’s screen time between 2020 and 2022, likely due to Covid lockdowns.
However, independent British experts have urged people to be cautious about the study, with some even calling its conclusions “irresponsible.”
They say the type of light used in the study is not comparable to the blue light emitted by televisions, computers and tablets, and that rats’ bodies behave differently than humans.
While the team, who presented their findings at a conference in Liverpool, said the study obviously had limitations given it was carried out on animals, but insisted their findings had potential implications for people. stock image
In the study, the team took 36 baby rats and divided them into three groups.
One cohort was exposed to natural light while the other two were exposed to six or 12 hours of blue light per day.
The experts then monitored the rats, divided equally in terms of sex, for the first signs of bone growth and puberty.
They found that the blue light group grew faster and therefore entered puberty earlier.
But Professor Pete Etchells, a psychology expert at Bath Spa University, who has been studying the impact of screen time, criticized the new research, which has not been published or peer-reviewed.
“This study has nothing to do with screen time or children; it’s a small study of limited blue light exposure in young rats,” he said.
‘It is simply incorrect, then, to claim that “excessive screen time” has been linked to early physical development.
Sunlight has a balance of what scientists call red and blue light, and experts are concerned that overexposure to the latter could cause a number of potential negative health problems in the future. stock image
“Furthermore, the type and intensity of light exposure used here cannot be easily translated into the practical reality of how children interact with screen-based technologies.
“Therefore, I am not clear what this study contributes, if anything, in terms of informing and reassuring the very real concerns that many people have about the potential positive and negative impacts of screen-based technologies.
Another critic was Professor Dorothy Bishop, an expert in developmental neuropsychology at the University of Oxford.
“I recommend using extreme caution when drawing conclusions from this study about the impact of light from screens on children,” he said.
He highlighted that the development of rats is very different from that of humans and that the methods used in the study did not reflect the lives of children.
For example, the rats were not given any breaks to look at the light, which does not mimic how children use technology.
However, experts have generally expressed concern about the potential impact of chronic blue light exposure.
Earlier this year, scientists at University College London (UCL) warned could represent a “time bomb” for public health, which could cause diabetes and even shorten lives.
Sunlight has a balance of what scientists call red and blue light.
As blue light is naturally seen during the day when the sun is shining, it naturally increases our attention, reaction times and mood, essentially making us more awake.
But modern LED lighting, as well as the increasing use of screens, have led to much greater blue light exposure than in previous generations.
Experts have discovered that excess blue light can alter the functioning of our cells, as well as alter our circadian rhythm, the body’s internal clock, which generates a series of negative health consequences.