Photo by Antonio Diaz / iStock
DAYLIGHT SAVINGS TIME, which began this past Saturday at 2 a.m, can interfere with the ability to fall asleep and to wake up at the desired times. The one-hour time change can exacerbate difficulties of people with chronic sleep problems such as insomnia and sleep apnea. And insufficient sleep over time can have a wide range of negative effects on everyone.
The association of sleep loss with increased risk of overeating, poor food choices and weight gain has recently been explained as the same system “targeted by the active ingredient of marijuana,” according to Eric Hanlon, PhD, research associate at the University of Chicago. “Sleep restriction boosts a signal that may increase the hedonic aspect of food intake” — that is, brings on the munchies.
Blood levels of the chemical messenger 2-AG (the endocannabinoid 2-arachidonoylglycerol) are typically low overnight and slowly rise during the day, peaking just after noon. Compared to when study subjects had a full night’s sleep, with insufficient sleep their 2-AG levels rose about 33% higher and remained elevated through the evening. During those periods, they expressed greater desire to eat and, when offered snacks, chose foods providing 50% more calories, including twice the amount of fat.
Previous studies have linked high levels of the appetite-boosting hormone ghrelin and low levels of the fullness-signaling hormone leptin to reduced sleep time and increased appetite. The Chicago research for the first time also measured blood levels of 2-AG, which stimulates the endocannabinoid system and enhances the desire for food intake.
Hanlon explained, “If you have a Snickers bar, and you’ve had enough sleep, you can control your natural response. But if you’re sleep deprived, your hedonic drive for certain foods gets stronger and your ability to resist them might be impaired.”
Sleep-deprived people also appear to have more trouble expressing and detecting emotions, especially positive ones. According to University of Pennsylvania psychology professor David Dinges, “a sleep-deprived person may say they’re happy but they still have a neutral face.” Also, they might see another’s happy face as neutral, and a neutral face as negative. And they have a low tolerance for disappointment.
The immediate effect of losing two hours of sleep has been compared to that of alcohol intoxication. Over time, sleep insufficiency increases mortality risk more than smoking, high blood pressure and heart disease. And it has been blamed for other chronic diseases such as hypertension, diabetes, depression and obesity, as well as for cancer.
A recently discovered network of fluid channels in the central nervous system called the “glymphatic system” functions as a waste disposal system for the brain. The glymphatic system drains toxins that can accumulate and damage brain cells — including amyloid-beta associated with Alzheimer’s disease — from the brain “at a rapid clip,” according to neuroscientists at the University of Rochester. This system, however, mainly operates during sleep and appears disengaged during wakefulness.
Among suggestions for adjusting to time changes such as daylight savings, the most often heard is to spend time outdoors in sunlight, being physically active when possible. And during the hours before bed, lower the lights and turn off technology including cell phones, iPads, computers and TV. Avoid eating and drinking alcohol too close to bedtime, and warm baths can help.
— Mary Carpenter
Mary Carpenter is the Well-Being Editor of MyLittleBird.
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