Light from Tablet Computers May Delay Sleep, Especially in Teens

I admit I love my gadgets – especially my laptop and e-reader, I’m also, as a doctor, aware of the effects that the artificial light from these devices can have on our sleep, especially following prolonged and late-night use.

The artificial, short-wave light from TV and computer screens can suppress melatonin production and throw off circadian rhythm, preventing deep, restorative sleep. Prolonged sleep disruption may also lead to increased risk for diabetes and obesity.  A new study  released in late August reinforces my opinion with some data.

Researchers at the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute in Troy, NY tested the effects of self-luminous tablets on melatonin suppression. Melatonin is a hormone produced by the pineal gland at night and is involved in regulating our sleeping and waking cycles.

The study was funded by Sharp Laboratories of America and led by Mariana Figueiro, associate professor at Rensselaer and director of the LRC’s Light and Health Program. Co-authors of the study are LRC director and professor Mark S. Rea, LRC research specialist Brittany Wood, and LRC research nurse Barbara Plitnick.

For the study, 13 participants used self-luminous tablets to read, play games and watch movies. The participants were divided into three groups. The first group viewed their tablets through a pair of clear goggles fitted with blue light. This was the “true positive” group because blue lights are known to be a strong stimulus for suppressing melatonin.

The second “control” group viewed their tablets through orange-tinted glasses, which filtered out the short-wavelength radiation that can suppress melatonin. The third group did not wear any glasses or goggles. Each tablet was set to full brightness.

The results of the study were clear: After only two hours of exposure to electronic devices with self-luminous “backlit” displays, the participants’ melatonin levels were suppressed by about 22 percent. According to lead researcher Mariana Figueiro, stimulation of the circadian system to this level may delay sleep in those using the devices prior to bedtime, especially in teens.

The researchers also determined that the type of task being performed on the tablets also determines how much light is delivered to the cornea, and therefore the impact the self-luminous light has on nighttime melatonin levels. In other words, the researchers pointed out that it is important to measure how much light a person receives from the self-luminous device.

So, what can be done with this new information? How can we use it to improve our sleep and general health? One, we can all become more aware of how much time we—and our children—spend staring at our tablets, computer and TV screens late at night. As adults, it is up to us to monitor ourselves and our children, and have the discipline to turn these machines off at least an hour before bedtime.

LRC research specialist Brittany Wood said, “Technology developments have led to bigger and brighter televisions, computer screens, and cell phones. To produce white light, these electronic devices must emit light at short wavelengths, which makes them potential sources for suppressing or delaying the onset of melatonin in the evening, reducing sleep duration and disrupting sleep. This is particularly worrisome in populations such as young adults and adolescents, who already tend to be night owls.”

Although pre-teens and teens love their late-night electronics, as parents, it is our responsibility to monitor our children’s computer use, or at the very least in older teens, educate them and make them aware of the potential; side effects of prolonged use.

Researcher Figueiro also feels that tablet display manufacturers can use this information to determine how their products affect circadian system regulation, and as a result, design more “circadian-friendly” electronic devices that could either increase or decrease circadian stimulation depending on the time of day. For example, screens that reduce circadian stimulation in the evening for a better night’s sleep, and increasing in the morning to encourage alertness.

Figueiro had another interesting idea about tablet light therapy: In the future, manufacturers might be able to use related data to design tablets that minimize symptoms of seasonal affective disorder, and sleep disorders in seniors. People might even be able to receive light treatments while playing games or watching movies, making light therapy much more enjoyable than just sitting in front of a light box.

Until manufacturers develop more “circadian-friendly” electronic devices that increase or decrease light exposure based on time of day, Figueiro offered several recommendations to reduce the effects of self-luminous tablet light on sleep, including dimming these devices at night as much as possible in order to minimize melatonin suppression, and, as I mentioned before, limiting the amount of time spent using these devices prior to bedtime.

Here’s another idea: Why not turn off the devices before bed, and pick up a good old fashioned paper book. You’ll be out like a light before you know it.

Read the full study entitled, “Light From Self-Luminous Tablet Computers Can Affect Evening Melatonin, Delaying Sleep.”

“Social Jetlag” Contributing to Global Weight Gain

Here’s another reason to get more sleep — and another new term to describe one of our modern maladies: “social jetlag.” What exactly is social jetlag? It is a syndrome caused by the discrepancy between our internal body clock and our social clock. And according to Professor Till Roenneberg, Ph.D. at the University of Munich's Institute of Medical Psychology in Germany, that gap between how much sleep we need and how much we’re actually getting is contributing to our global weight gain and the growing worldwide obesity epidemic.

Each of us has a physiological clock, and that internal clock — also known as our circadian rhythm — is regulated by daylight and darkness to prompt us to go to sleep or wake up. We also have a social clock of things that make up our daily lives, such as our work schedules and social calendars. The problem is, in our modern society of too-late work hours and too much time in front of computer screens, we are listening to our social clocks more than our physiological clocks, causing a greater sleep gap known as social jetlag. As a person’s circadian rhythm gets more out of whack, their physiological clock gets set later and later, keeping them awake into the night, and feeling chronically tired during the day.

Professor Roenneberg and his fellow researchers in Munich discovered the negative effects of social jetlag after compiling and studying the sleep habits of more than 65,000 adults over the past 10 years. Roenneberg and his team recorded sleep times and other data of the participants, such as height and weight, and started to draw conclusions.

The results of the study — which you can read in the May 10 issue of Current Biology — showed that people with different weekday and weekend sleep schedules—i.e., those with more social jetlag — were three times more likely to be overweight. That is a significant increase worth repeating: Three times more likely to be overweight!  Furthermore, the body mass index (BMI) of the overweight participants tended to increase as the gap between their weekday and weekend sleep clocks widened.

Two-thirds of participants reported at least one hour's difference in their average weekday and weekend sleep schedules, and more than 10 percent reported three-plus hours difference between their weekday and weekend sleep schedules. Roenneberg and his colleagues also found that people who are chronically sleep-deprived are also more likely to smoke and drink more alcohol and caffeine.

The results of the study are similar to those of previous studies linking a higher body mass index and even diabetes to the irregular sleep schedules and sleep deprivation of shift workers. But I applaud the efforts of Roenneberg and his team for their work in particular, because they are bringing a public awareness of a growing syndrome that is affecting many people worldwide — not just shift workers or those with irregular work schedules.

So, why does social jetlag cause weight gain? One of the theories is that late hours encourage irregular meal times and late-night eating, when the body has more difficulty digesting and metabolizing food. That translates into body fat. Another is that chronically tired people are less likely to exercise and more likely to smoke and drink, further contributing to weight gain.

Whatever the causes, it is in all our personal best interests to become more aware of our own physiological clocks and get more restful sleep. Doing so can help us all maintain a healthy body weight, avoid many health problems, feel better and live happier, more productive lives. In the words of Professor Roenneberg, “Good sleep and enough sleep is not a waste of time but a guarantee for better work performance and more fun with friends and family during off-work times.” Knowledge of the study and an increased awareness of the effects of social jetlag can also have positive effects on the economy and education: Companies can make more informed decisions about employees’ work schedules and schools can make more educated decisions about school hours.

So, now that you have this new knowledge about social jetlag, your physiological and social clocks and how a gap between your weekday and weekend sleep schedules can contribute to your weight gain, what are you going to do about it? I present you with a personal challenge that will only help you feel better. I challenge you to get more sleep. Turn off the TV and computer and go to bed earlier. Forego that invitation for a late-night dinner. Spend more time outdoors, and if you’re stuck in an office all day, try to sit near a window. I promise you, you’ll feel less social jetlag.

To read Professor Roenneberg and his team’s full report entitled, “Social Jetlag and Obesity,” published in the May 10 issue of Current Biology.

Who’s Suffering More from Lack of Sleep—Men or Women?

This week, I was interviewed by WCBS-TV New York for a news segment called, “Sleep: the Battle of the Sexes.” The topic was one I am very familiar with: People suffering from lack of sleep, and how it can affect daytime mood, mental acuity, job performance and relationship intimacy.

The show drilled down a bit farther and asked: who is more likely to suffer from a sleep disorder, men or women? And of the two genders, which performs better despite a lack of sleep?

What we know is that men and women have different circadian rhythms. According to an article by the Proceedings of the National Academy of Sciences of the United States of America,  “The circadian rhythms of melatonin and body temperature are set to an earlier hour in women than in men, even when the women and men maintain nearly identical and consistent bedtimes and wake times. Moreover, women tend to wake up earlier than men and exhibit a greater preference for morning activities than men.”

In other words, women tend to go to sleep and wake up earlier than men. We also know thanks to a Penn State study that women need 6.8 hours of sleep per night, while men require just 6.2 hours. While scientific studies are interesting, there is a discrepancy between these numbers and what I am seeing in my office at the Manhattan Snoring and Sleep Center.

Based on the facts, one would think women are getting to sleep earlier and sleeping longer than their male counterparts. But are women getting the sleep they need? In my anecdotal opinion, they are not, and they are suffering quietly for it. In our society, men are stressed out, but women are really stressed out. The physical demands of balancing career and family, along with the mental strain of worrying about finances and future is taking its toll on the women in our society. 

Don’t get me wrong, men worry and suffer from sleep disorders too. But they seem more willing to speak up and seek treatment. Women, on the other hand, being the selfless caregivers they are, stay focused on others and what needs to be done and power through their day. Which explains another Penn State study that found sleep deprived women made fewer mistakes compared to men in a series of computer tasks. It seems that, although women need more sleep, they do better without it because, for better or worse, they’re just more used to it.

Whether a man or woman is suffering from a lack of sleep, the fact is that a sleep disorder can lead to negative health issues, including an increased chance of hypertension, heart disease, osteoporosis and inflammatory disease.

In addition to personal health issues, a sleep disorder can wreak havoc on a relationship. The partner of a patient once shared with me how his snoring and sleep apnea had impacted their relationship. It led to weeks without quality REM sleep, and she said it left her feeling groggy with low energy, cranky, unable to concentrate for long and she was more prone to getting sick. His constant snoring caused her to start sleeping on the couch, which led to resentment, lack of intimacy and loss of connection.

I have made it clear in previous blogs that I am not a marriage counselor or relationship expert. But I can tell you unequivocally that, if you or your partner snores or suffers from a lack of sleep on a consistent basis, it will negatively affect your relationship.

In the end, circadian rhythms and who performs better and the sex of the person with the sleep disorder doesn’t matter. What matters is getting it treated and keeping the relationship healthy.

This also bears repeating: Turn off the TV when you go to sleep. Falling asleep with the TV or computer on interrupts deep REM sleep because the light from the screens interfere with the production of melatonin, a hormone that tells our bodies when it’s time to go to sleep. Do yourself a favor and turn off the TV, computer and lights at night. Your brain and body will thank you for it the next day.

To watch “Sleep: The Battle of the Sexes” on CBS2 New York, click here.

Stop Snoring — It Can Be the Secret to Happy Marriage

I am by no means a marriage therapist. However, I hear couples complain all the time in my practice. They come in for a snoring test appointment, and within seconds the husband makes a comment such as “my wife made me come.” Snoring is more common in men than women, but the reverse is also common.

The snoring spouse who feels “dragged” to the doctor’s office is resentful that his or her snoring problem can’t be left alone. The spouse that does the dragging-in is frustrated and tired. Ordinarily affectionate couples can have a strain in their relationship caused by snoring. Sometimes if it wasn’t for their spouse, a snorer wouldn’t even know they had a problem. As one of my patients recently told me, “I was very surprised when my lovely wife first clued me in that I was snoring at night. It was disturbing her sleep, but I didn’t realize that snoring was the cause of my own fatigue.”

The reason for resentment is understandable. Snoring can cause daytime symptoms that can cause serious problems in one’s waking life, and unfortunately, it is not just the snorer that suffers – the snorer’s spouse can suffer just as much. According to the National Sleep Foundation,  39% of American adults get less than seven hours of sleep each weeknight, and more than one in three (37%) are so sleepy during the day that it interferes with daily activities. The sleep loss associated with snoring—whether it’s the snorer or the bed partner who is awakened by the snoring, interrupts important recuperative sleep which can impair a person’s ability to perform cognitive tasks involving memory, learning, reasoning, and mathematical processes. It can impair motor skills and can cause morning headaches, irritability, burnout and depression to mention just a few symptoms.

Symptoms can be even more severe for the snorer if they have sleep apnea, a condition which causes them to stop breathing often many times a night, and wake gasping for air. Sleep apnea is linked to lung and heart disease, diabetes, obesity and stroke.

The disruption of sleep from snoring is causing couples to have a hard time sleeping together. Fifty-three percent of adults say they have relationship problems because of their or their partner's sleep disorder, the National Sleep Foundation found in a recent study. To avoid the symptoms of daytime sleepiness, many couples choose not to sleep together in the same bed.

In the book, "Two in a Bed: The Social System of Couple Bed Sharing," author Paul C. Rosenblatt interviewed 42 couples, and examined how sharing a bed affects the couple’s relationship. Many couples described the intimacy and comfort level of sleeping in the same bed is extremely important to their relationship. As he describes in the book, in their time together before drifting off to sleep, “couples catch up on what's going on with one another, plan, make decisions, deal with disagreements and solve problems.”

With their hectic schedules, many couples often only have this time to catch up. It is no wonder why it’s crucial to their relationship. Unfortunately snoring can force one spouse into another room for the sake of sleep, and this crucial together time is hard to replace in their busy lives otherwise.

If your marriage is suffering because you or your spouse snores, the key to reconciling is to understand that snoring is a symptom of a physical condition, such as sleep apnea, sinusitis, or nasal obstruction and it can be treated. There are many non-surgical, in-office and minimally invasive treatments available to snorers today. Although I would never make the claim that I’ve saved marriages, I’ve heard back many times from patients who tell me that it wasn’t until after their snoring was cured did they realize how much happier they are snuggling next to their spouse again.

The Stroke Connection: Heavy Snoring and Narrow Arteries

By David Volpi, M.D., P.C., F.A.C.S., The Manhattan Snoring and Sleep Center

In a study completed last year in Australia, researchers calculated that heavy snorers have an elevated risk for carotid artery stenosis, a narrowing of the arteries that supply the brain with blood. When those arteries are blocked, it can lead to stroke.

It’s been long known that high cholesterol, hypertension, smoking and obesity are linked to carotid artery narrowing. This new risk as discovered after 110 volunteers – a mixture of men and women ages 45-80—were measured for the extent of plaque in the arteries and spent the night in a sleep lab monitoring the timing of their snoring. The study showed that those that were the heaviest snorers (after adjusting for sex, body mass index, hypertension and other factors) had the 10 times the risk of those who snored the least.

Associate Professor of Medicine at the University of Sydney, John R. Wheatley was the lead researcher, and believes that the vibrations of snoring may cause damage to the epithelium, the cells that line the inside of the artery, leading to inflammation and plaque buildup. He acknowledges that the results of this study do not establish a “causal relationship” between artery blockage and snoring. For that a much larger sample must be studied. However it is clear that the study reveals heavy snoring may increase the risk for stroke.

Are you a heavy snorer? Snoring may be caused by a number of factors, and can be treated. Often lifestyle changes such as losing weight, exercise, quitting smoking and stopping alcohol consumption prior to bed are enough to cause snoring to stop. However, sometimes snoring is caused by physical issues such as nasal obstruction or chronic sinus infections. Whatever the cause, there are non-surgical and surgical means that can treat snoring.

If you are a heavy snorer, we recommend you have an examination by an otolaryngologist (ear, nose and throat) physician to assess what is causing your snoring and how it should be treated. For more information on the causes of snoring, visit www.nycsnoringsleepapneacenter.com.

If you’re within the New York tri-state area, contact the Manhattan Snoring and Sleep Center today to schedule an appointment.