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New study says blue light at bedtime may not be harmful

A young man sleeps in bed in the glow of blue light
Dr. Jain says we should teach ourselves how to relax in the evening and be relaxed through our sleeping period.

Previous research has warned against exposing ourselves to blue light from TV and electronics an hour before bedtime. It can prevent the brain from secreting the melatonin believed to help us get to sleep.

But a new study says this may not be true for all people. KERA’s Sam Baker talked about this with Dr. Vikas Jain, a sleep specialist in Plano and Medical Director of the Pediatric Sleep Institute affiliated with Texas Health.

The new study found that even though there might be some influence on the suppression of melatonin, it didn't seem like exposure to bright light significantly impacted a person's ability to fall asleep.

They looked at, for example, some teenagers who play games and watch videos on their iPads on either a bright white screen, a dim white screen, or a bright white screen with a blue light filter. What they found is that the teens who use the bright screen took about 3.3 minutes longer to fall asleep than those who were using the dim screen. So, it didn't seem like there was a significant difference in timing to fall asleep.

But the study's take-home message was we're all different, and that you can't just apply one rule or a one-size-fits-all in terms of that 30-minutes-to-an-hour recommendation we've previously given.

I do have to wonder, though, if it’s solely about the blue light or the kind of content you're consuming before bedtime?

That was one of the things that the article was discussing. If you're watching sort of passive content, that could be very different than watching very engaging content, because there might be a heightened sense of arousal depending on the content that's being built.

Particularly since you're dealing with pediatric patients, what do you tell them or their parents about handling blue light?

The first thing I generally recommend is making sure we're giving ourselves the opportunity to get enough sleep at night, because if you don't even do that first step, a lot of the other things may not even be as helpful.

So, like making sure that we have some rules around bedtime, rules surrounding technology use around bedtime. I do think it's still helpful to, you know, try to minimize exposure to bright light, especially blue light, in the evening.

But if you find that it's a way to wind down, or it might help that child reduce their anxiety in the evening or around bedtime, it could still be a helpful tool. We need to make sure, that when we use that tool, we're also tracking the impact both ways.

So the other helpful hint for parents is, whether you choose to use blue light or eliminate it, I would potentially consider a two-week period with each and see how your child does. Does it seem to have an influence one way or the other, or no influence at all? Because that might help you decide if it's something you want to continue to incorporate into your child's bedtime routine.

The best thing to experiment at home and see what works best for you?

In general, a concept that I try to teach a lot of my patients is that we never want to teach our brain how to be awake in bed. If you're doing things that are very stimulating in the middle of the night, then that's what tends to lend itself towards the development of insomnia and the persistence of insomnia.

So, what we want to try to do is really teach ourselves how to relax in the evening and be relaxed through our sleeping period. Again, I'm not opposed to the use of watching TV at night, but I usually recommend to my patients to not do that in bed. Go somewhere else so that we're not teaching our brains how to be awake in bed.


Blue Light review

Blue Light: What It Is and How It Affects Sleep
The influence of blue light on sleep, performance and wellbeing in young adults: A systematic review

Blue Light and Sleep: Tips for Older Adults

Sam Baker is KERA's senior editor and local host for Morning Edition. The native of Beaumont, Texas, also edits and produces radio commentaries and Vital Signs, a series that's part of the station's Breakthroughs initiative. He also was the longtime host of KERA 13’s Emmy Award-winning public affairs program On the Record. He also won an Emmy in 2008 for KERA’s Sharing the Power: A Voter’s Voice Special, and has earned honors from the Associated Press and the Public Radio News Directors Inc.