By Michael S. Jaffee, University of Florida
For most of the United States, the clock goes back one hour on Sunday morning, November 1st, the “fallback” for daylight saving time. Many of us appreciate the extra hour of sleep.
But for millions, that gain won’t counteract the inadequate sleep they get the rest of the year. About 40% of adults – 50 to 70 million Americans – get fewer than the recommended minimum hours of seven hours per night.
Some researchers are concerned about how the biannual change affects the physiology of our body. The American Academy of Sleep Medicine, the largest scientific organization studying sleep, is now looking to replace daylight saving time with a year-round time. That way, our internal circadian clocks would not be misaligned for half a year. And it would remove the security risk from loss of sleep during the transition to summer time.
I’m a neurologist at the University of Florida. I’ve been researching how lack of sleep can affect the brain. In the 1940s, most American adults slept an average of 7.9 hours a night. Today it’s only 6.9 hours. In other words, in 1942, 84% of us got the recommended seven to nine hours; In 2013 it was 59%. To break it down further, a January 2018 study by Fitbit reported that men got even less sleep per night than women, around 6.5 hours.
The case for sleep
Sleep-deprived problems go beyond being tired. Compared with those who got enough sleep, adults with short sleepers – who had less than seven hours a day – were more likely to report over 10 chronic conditions, including heart disease, diabetes, obesity, asthma, and depression.
Children who need more sleep than adults face even greater challenges. To promote optimal health, six to twelve year olds should sleep nine to 12 hours a day. Young people aged 13 to 18, eight to 10 hours. However, a survey by the Sleep Foundation of parents found that children are getting at least an hour less. And researchers have found that sleep deprivation for as little as an hour can damage a child’s developing brain and interfere with coding of memory and attention in school.
Sleep affects every one of our biological systems. Serious consequences can occur if the quality of sleep is poor. Here is a short list: Blood pressure can rise. The risk of coronary artery disease could increase. Our endocrine system releases more cortisol, a stress hormone. We become more aroused by the “fight or flight” syndrome. There is a decrease in growth hormone and muscle maintenance. There is a higher likelihood of increased appetite and weight gain. The body has lower glucose tolerance and higher insulin resistance, which in the long run means an increased risk of type 2 diabetes.
Sleep deprivation is linked to increased inflammation and decreased levels of antibodies to fight infection. It can also lead to a decrease in pain tolerance, reaction times, and memory. Occupational studies show that sleep loss can lead to poor job performance, including more days missed and more car accidents.
Recent research suggests that the body’s waste elimination process relies on sleep to remove harmful proteins from the brain, particularly abnormal variants of amyloid. These are the same proteins that are elevated in Alzheimer’s patients. Studies show that older adults who sleep less have a greater accumulation of these proteins in their brain.
Getting enough sleep, on the other hand, helps the body in many ways by protecting against some of these harmful effects and by strengthening the immune system.
The problem with daylight saving time
Most of the risk associated with summer time occurs in the spring, when we turn the clock forward and lose an hour of sleep. The idea of a national permanent all year round has support, but there is disagreement as to whether the fixed time should be standard time or daylight saving time.
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States that advocate permanent summer time are usually the ones that rely on tourism. Environmentalists who prefer lower energy consumption through morning heating and nightly air conditioning often support a permanent standard time. Religious groups whose prayer times are associated with sunset and sunrise also prefer a permanent standard time. So are many educators who refuse to take children to school in the morning when it is still dark.
When considering which system is best for a national year-round standard, keep the following in mind: The American Academy of Sleep Medicine has recommended using a permanent standard time – a better way to adjust to our natural time of day and health and safety risks to minimize.
And just think: if we switch to permanent standard time, you won’t lose an hour of sleep every spring for the first time in decades.
Michael S. Jaffee, vice chairman, Department of Neurology, University of Florida
This article is republished by The Conversation under a Creative Commons license. Read the original article.