How the Internet Will Change Your BodyDr. Matthew Edlund, MD, MOH
Part II of a four-part series
Posted December 15, 2010
Body clocks affect everything you do. Ask any shift worker. They’re a group with higher cardiovascular mortality and higher cancer rates. Already government agencies are starting to label shift work a workplace carcinogen.
In which case it should also be deemed a home carcinogen. The Net is rapidly turning much of the population into biological shiftworkers—and they’re willingly going along.
There’s far, far more than texting done with the Net, but texting is becoming more and more a preferred Net access for Americans. We text everywhere, anywhere, anytime.
The recent Pew Memorial Trust survey showed the average 12- to 17-year-old texting 110 times a day. That includes the night. Texting is increasingly interrupting sleep, not just daytime work.
And it’s not only teenagers. Many of my friends has commented on families coming to the restaurant or family dining table, taking out their cell phones, and starting to text—without saying a word to each other. Often they text the person next to them rather than talk to them. Teenagers often state they prefer texting a friend to speaking to them directly for myriad reasons varying from “efficiency” to shyness.
What is less commented on is not just that people will text everywhere—in their car, seated in front of their computers, even when engaged in sex—but that texting now is turning night into day into night.
The human body is exquisitely built to operate very differently over the 24 hour day, with markedly changed functions from daylight to nighttime. Wipe out this innate timing principle and you get lots of unhealthy results, including:
1. Less sleep. Particularly when people sleep less on average than seven hours a night, and especially with six hours or less, you see greater cardiovascular disease, stroke, hypertension, heart attacks, and depression (see my Power of Rest for my specifics.)
2. Interrupted sleep. Wake people frequently and you don’t get the sleep continuity required for REM and deep sleep, phases of sleep needed for memory consolidation and learning. If laboratory results can be trusted, this is a quick way to a dumber population.
3. More weight. Shortened sleep interferes with basic metabolism, the present identified culprits fingering the hormones insulin, ghrelin and leptin. Short sleep makes people look prediabetic awfully quickly. Shortened sleep also leads to people desiring more fatty and sugary food, as Susan Redline’s research has shown.
4. Changing your inner time. Ever watched a midnight movie? You may remember the bright light flashes of the kids checking messages on their cell phones—and texting back. Even very short bursts of night-time light cut off melatonin production. Some argue that disrupting melatonin paves the way to more cancer, but night-time light certainly changes biological clocks:
Our inner clocks are set and calibrated by light. We possess special cells in our eyes that help tell the brain the time and day outside. These cells do not report to our visual cortex—they don’t change what we see. When blind people lack these cells, they can’t operate on a normal 24 hour day, with terrible social and economic effects.
More important, give the brain bright light during the night and you move inner body clocks later—which makes you go to bed and get up later. Not great things if you’re trying to get to school or work on time and actually hope to pay attention. Changing inner clocks also changes how you process food.
5. More stress. Rest is regeneration. That’s how you survive—by rapidly replacing yourself. Screw up rest and you mess up your health. The many systems by which your body works become disaggregated, making everything less efficient and setting you up for the development of disease.
So when people get stressed they do more than increase cortisol and gain weight. They also get cranky, tired, inattentive and distracted—even angry. More internet use correlates with greater violence, particularly in young kids who use the Net hours a day. They fight a lot.
Other Effects of Stress
Freqeuent youthful Net users also have more interrupted brains. Interrupted brains don’t rewire themselves as effectively so they often don’t learn as well. This learning includes explicit memory—the kind we usually think about—and implicit memory, the stuff we use when we perform a muscle (“motor”) operation, like bicycling or throwing a baseball.
However, your brain remembers a lot more than the names of past boyfriends and how to hit a tennis ball. Other memories operate for coordination of three dimensional spatial sense; your immune function; how your gut responds to different foods. Much of this information lies below the conscious decision making level yet is critical to your survival.
What interrupted attention and rest are doing to all these functions is not well studied. However, the auguries are not good. If you interrupt your brain activities a lot, as when you disrupt body clocks, everything seems to work less well.
Think a second about the timer on your car. What happens when your engine timer is no longer calibrated? Your car won’t sound very good—and you don’t want it accelerating on the highway.
Now think about what happens when you disrupt the basic timing mechanisms of your body.
Through many hormonal and neurotransmitter effects, stress rewires brain and body in many unhealthy ways. Yet the largest effects of the Net on the body may be in how they will change body image.
Dr. Matthew Edlund, M.D., M.O.H., is an internationally recognized expert on rest, sleep, and body clocks. His books include The Body Clock Advantage, Designed to Last, and Psychological Time and Mental Illness. His new book, The Power of Rest, shows that rest is a skill that rebuilds, renews, and rewires mind and body, and can increase productivity, health, and pleasure. For more information, visit his website, TheRestDoctor.com. You can also subscribe to his new Fitcast via the iTunes Store.