Daily exposure to blue light may accelerate aging, even if it doesn't reach your eyes

October 17, 2019

Science Daily/Oregon State University

Prolonged exposure to blue light, such as that which emanates from your phone, computer and household fixtures, could be affecting your longevity, even if it's not shining in your eyes.

New research at Oregon State University suggests that the blue wavelengths produced by light-emitting diodes damage cells in the brain as well as retinas.

The study, published today in Aging and Mechanisms of Disease, involved a widely used organism, Drosophila melanogaster, the common fruit fly, an important model organism because of the cellular and developmental mechanisms it shares with other animals and humans.

Jaga Giebultowicz, a researcher in the OSU College of Science who studies biological clocks, led a research collaboration that examined how flies responded to daily 12-hour exposures to blue LED light -- similar to the prevalent blue wavelength in devices like phones and tablets -- and found that the light accelerated aging.

Flies subjected to daily cycles of 12 hours in light and 12 hours in darkness had shorter lives compared to flies kept in total darkness or those kept in light with the blue wavelengths filtered out. The flies exposed to blue light showed damage to their retinal cells and brain neurons and had impaired locomotion -- the flies' ability to climb the walls of their enclosures, a common behavior, was diminished.

Some of the flies in the experiment were mutants that do not develop eyes, and even those eyeless flies displayed brain damage and locomotion impairments, suggesting flies didn't have to see the light to be harmed by it.

"The fact that the light was accelerating aging in the flies was very surprising to us at first," said Giebultowicz, a professor of integrative biology. "We'd measured expression of some genes in old flies, and found that stress-response, protective genes were expressed if flies were kept in light. We hypothesized that light was regulating those genes. Then we started asking, what is it in the light that is harmful to them, and we looked at the spectrum of light. It was very clear cut that although light without blue slightly shortened their lifespan, just blue light alone shortened their lifespan very dramatically."

Natural light, Giebultowicz notes, is crucial for the body's circadian rhythm -- the 24-hour cycle of physiological processes such as brain wave activity, hormone production and cell regeneration that are important factors in feeding and sleeping patterns.

"But there is evidence suggesting that increased exposure to artificial light is a risk factor for sleep and circadian disorders," she said. "And with the prevalent use of LED lighting and device displays, humans are subjected to increasing amounts of light in the blue spectrum since commonly used LEDs emit a high fraction of blue light. But this technology, LED lighting, even in most developed countries, has not been used long enough to know its effects across the human lifespan."

Giebultowicz says that the flies, if given a choice, avoid blue light.

"We're going to test if the same signaling that causes them to escape blue light is involved in longevity," she said.

Eileen Chow, faculty research assistant in Giebultowicz's lab and co-first author of the study, notes that advances in technology and medicine could work together to address the damaging effects of light if this research eventually proves applicable to humans.

"Human lifespan has increased dramatically over the past century as we've found ways to treat diseases, and at the same time we have been spending more and more time with artificial light," she said. "As science looks for ways to help people be healthier as they live longer, designing a healthier spectrum of light might be a possibility, not just in terms of sleeping better but in terms of overall health."

In the meantime, there are a few things people can do to help themselves that don't involve sitting for hours in darkness, the researchers say. Eyeglasses with amber lenses will filter out the blue light and protect your retinas. And phones, laptops and other devices can be set to block blue emissions.

"In the future, there may be phones that auto-adjust their display based on the length of usage the phone perceives," said lead author Trevor Nash, a 2019 OSU Honors College graduate who was a first-year undergraduate when the research began. "That kind of phone might be difficult to make, but it would probably have a big impact on health."

https://www.sciencedaily.com/releases/2019/10/191017101253.htm

Too much screen time for the kids? Grandparents may also be complicit

In the age of high-tech electronics many kids spend about half their visit with grandparents watching videos or playing with apps

July 8, 2019

Science Daily/Rutgers University

Grandparents have long been associated with letting their grandchildren do things their parents would never permit. Candy. Extended bedtime. Too much television. Carefree fun. They like to spoil their grandchildren.

A new study by Rutgers and other researchers finds that today's grandparents are still true to their traditional fun-loving image -- allowing their grandchildren, while under their supervision, to spend about half of their time on a mobile phone, tablet, computer or TV.

The study, published in the Journal of Children and Media, suggests that grandparents should restrict media use by setting simple rules for screen time when babysitting. This is particularly needed when children bring a device from home and expect to watch even more.

"Grandparents play a very significant role in raising their grandchildren. We need to educate them about the impact of media on children's lives and on proper use that will benefit the wellbeing of their grandchildren," said study co-author Dafna Lemish, a distinguished professor of journalism and media studies and associate dean for programs at Rutgers University-New Brunswick's School of Communication and Information.

The study reviewed the experiences of grandparents of children ages 2-7 who take care of their grandchildren at least once per week and found that during an average four-hour visit, the children spent two hours either watching videos or playing games on electronic devices.

Among the findings:

·     Many grandparents feel less confident in managing children's use of interactive media, such as games, than in managing their use of non-interactive videos. This may be due to lack of experience with games or apps.

·     Some children's parents give the grandparents instructions about how to handle media use. This, ironically, leads to more screen time viewing.

·     Grandfathers in the study allowed more interactive screen time than did grandmothers, perhaps because they are more comfortable with the technology.

·     On average, grandparents had more difficulty in managing the media use of boys and older children than of girls and younger children. Boys on average spent 17 minutes more than girls with media related activities.

·     Grandparents allow more screen time when they care for children in their own homes versus the children's homes. They also allow more screen time when the child brings a tablet or other device from home, as 22 percent of grandchildren do.

·     The lowest amount of time dedicated to media use per visit with grandparents was found among children aged 2 to 3, at an average of 98 minutes per visit. Children aged 4 to 5 spent an average of 106 minutes with electronic devices, and children aged 6 to 7 had 143 minutes of screen time, on average per visit.

The study offers the following recommendations:

Grandparents who set strict rules (such as not more than an hour; not before bedtime; not during meals) succeed in reducing their grandchildren's screen time.

Parents should supply toys, games and books to help grandparents keep children busy.

https://www.sciencedaily.com/releases/2019/07/190708154051.htm

Screen time -- even before bed -- has little impact on teen well-being

April 5, 2019

Science Daily/Association for Psychological Science

Data from more than 17,000 teenagers show little evidence of a relationship between screen time and well-being in adolescents. The study, published in Psychological Science, a journal of the Association for Psychological Science, casts doubt on the widely accepted notion that spending time online, gaming, or watching TV, especially before bedtime, can damage young people's mental health.

"Implementing best practice statistical and methodological techniques we found little evidence for substantial negative associations between digital-screen engagement and adolescent well-being," said Amy Orben, a Researcher at the Oxford Internet Institute (OII) and College Lecturer at the Queen's College, University of Oxford.

"While psychological science can be a powerful tool for understanding the link between screen use and adolescent well-being, it still routinely fails to supply stakeholders and the public with high-quality, transparent, and objective investigations into growing concerns about digital technologies. Analyzing three different datasets, which include improved measurements of screen time, we found little clear-cut evidence that screen time decreases adolescent well-being, even if the use of digital technology occurs directly before bedtime," said Professor Andrew Przybylski, Director of Research at the OII and coauthor on the study.

The research found that adolescents' total screen time per day had little impact on their mental health, both on weekends and weekdays. It also found that the use of digital screens 2 hours, 1 hour, or 30 minutes before bedtime didn't have clear associations with decreases in adolescent well-being, even though this is often taken as a fact by media reports and public debates.

Unlike other studies, the Oxford research analyzed data from Ireland, the US, and the UK to support its conclusions. The researchers used a rigorous methodology to gather how much time an adolescent spends on screens per day, including both self-reported measures and time-use diaries. This is important as many studies are based solely on self-reported digital technology use, even though recent work found only one third of participants give accurate accounts of how much time they spend online when asked after the fact.

The researchers were also able to create a comprehensive picture of teens' well-being, examining measures of psychosocial functioning, depression symptoms, self-esteem, and mood, with data provided by both young people and their caregivers.

Additionally, the final of the three studies conducted was preregistered, meaning that the researchers publicly documented the analyses they would run before they analyzed the data. This prevents hypothesizing after the results are known, a challenge for controversial research topics.

"Because technologies are embedded in our social and professional lives, research concerning digital-screen use and its effects on adolescent well-being is under increasing scrutiny," said Orben. "To retain influence and trust, robust and transparent research practices will need to become the norm -- not the exception. We hope our approach will set a new baseline for new research on the psychological study of technology," added Przybylski.

The insights come days ahead of the anticipated release of the UK government's new White Paper on Online Harms, which is expected to set out plans for legislation governing social media companies. This new study builds on previous work by Orben and Przybylski that used novel and transparent statistical approaches to show that technology use has a minuscule influence on adolescent well-being.

The study used data from Ireland, the US, and the UK. In Ireland, it covered 5,363 young people tracked under the Growing Up in Ireland project. In the US, the data covered 709 subjects of a variety of ages compiled by the United States Panel Study of Income Dynamics. And in the UK, the dataset included responses from 11,884 adolescents and their caregivers surveyed as part of the Millennium Cohort Study.

https://www.sciencedaily.com/releases/2019/04/190405080922.htm

Children's sleep not significantly affected by screen time

November 5, 2018

Science Daily/University of Oxford

As young people spend an increasing amount of time on electronic devices, the effects of these digital activities has become a prevalent concern among parents, caregivers, and policy-makers. Research indicating that between 50 percent to 90 percent of school-age children might not be getting enough sleep has prompted calls that technology use may be to blame. However, new research has shown that screen time has very little practical effect on children's sleep.

Screens are now a fixture of modern childhood. And as young people spend an increasing amount of time on electronic devices, the effects of these digital activities has become a prevalent concern among parents, caregivers, and policy-makers. Research indicating that between 50% to 90% of school-age children might not be getting enough sleep has prompted calls that technology use may be to blame. However, the new research findings from the Oxford Internet Institute at the University of Oxford, has shown that screen time has very little practical effect on children's sleep.

The study was conducted using data from the United States' 2016 National Survey of Children's Health. Parents from across the country completed self-report surveys on themselves, their children and household.

"The findings suggest that the relationship between sleep and screen use in children is extremely modest," says Professor Andrew Przybylski, author of the study published in the Journal of Pediatrics. "Every hour of screen time was related to 3 to 8 fewer minutes of sleep a night."

In practical terms, while the correlation between screen time and sleep in children exists, it might be too small to make a significant difference to a child's sleep. For example, when you compare the average nightly sleep of a tech-abstaining teenager (at 8 hours, 51 minutes) with a teenager who devotes 8 hours a day to screens (at 8 hours, 21 minutes), the difference is overall inconsequential. Other known factors, such as early starts to the school day, have a larger effect on childhood sleep.

"This suggests we need to look at other variables when it comes to children and their sleep," says Przybylski. Analysis in the study indicated that variables within the family and household were significantly associated with both screen use and sleep outcomes. "Focusing on bedtime routines and regular patterns of sleep, such as consistent wake-up times, are much more effective strategies for helping young people sleep than thinking screens themselves play a significant role."

The aim of this study was to provide parents and practitioners with a realistic foundation for looking at screen versus the impact of other interventions on sleep. "While a relationship between screens and sleep is there, we need to look at research from the lens of what is practically significant," says Przybylski. "Because the effects of screens are so modest, it is possible that many studies with smaller sample sizes could be false positives -- results that support an effect that in reality does not exist."

"The next step from here is research on the precise mechanisms that link digital screens to sleep. Though technologies and tools relating to so-called 'blue light' have been implicated in sleep problems, it is not clear whether play a significant causal role," says Przybylski. "Screens are here to stay, so transparent, reproducible, and robust research is needed to figure out how tech effects us and how we best intervene to limit its negative effects."

https://www.sciencedaily.com/releases/2018/11/181105132939.htm