Sleep tight and stay bright? Better sleep in younger years may aid memory in old age
Sound sleep in young and middle-aged people helps memory and learning, but as they hit their seventh, eighth and ninth decades, they don’t sleep as much or as well - and sleep is no longer linked so much to memory, a Baylor researcher says.
That raises an “alluring question” - whether improving sleep early in life might delay, or even reverse, age-related changes in memory and thinking, said Michael K. Scullin, Ph.D., director of Baylor University’s Sleep Neuroscience and Cognition Laboratory, who examined 50 years of sleep research for an article in the journal Perspectives on Psychological Science.
“It’s the difference between investing up front rather than trying to compensate later,” said Scullin, assistant professor of psychology and neuroscience in Baylor’s College of Arts & Sciences. “We came across studies that showed that sleeping well in middle age predicted better mental functioning 28 years later.”
The article - “Sleep, Cognition, and Normal Aging: Integrating a Half Century of Multidisciplinary Research” - notes that the benefits of a sound night’s sleep for young adults are diverse and unmistakable. One example is that a particular kind of “deep sleep” called “slow-(brain)-wave-sleep” helps memory by taking pieces of a day’s experiences, replaying them and strengthening them for better recollection.
By the time people reach middle age, more sleep during the day, such as an afternoon nap, also helps people’s memory and protects against its decline - as long they don’t skimp on nighttime sleep.
But as they grow older, people wake up more at night and have less deep sleep and dream sleep - both of which are important for overall brain functioning, Scullin said.
As we age we often experience normal changes in our sleeping patterns. We may become sleepy earlier, wake up earlier, or enjoy less deep sleep. Although these changes are a normal part of aging, disturbed sleep, waking up tired every day, and other symptoms of insomnia are not a normal part of aging. Sleep is just as important to our physical and emotional health over the age of 50 as it was when we were younger. These tips can help you overcome age-related sleep problems and get a good night’s rest.
The importance of sleep for older adults
No matter what your age, sleeping well is essential to your physical health and emotional well-being. For older adults, a good night’s sleep is especially important because it helps improve concentration and memory formation, allows your body to repair any cell damage that occurred during the day, and refreshes your immune system, which in turn helps to prevent disease.
Many physicians consider sleep to be a barometer of a person’s health, like taking his or her temperature. Older adults who don’t sleep well are more likely to suffer from depression, attention and memory problems, and excessive daytime sleepiness. They are likely to suffer more nighttime falls, have increased sensitivity to pain, and use more prescription or over-the-counter sleep aids. Insufficient sleep can also lead to many serious health problems in older adults, including an increased risk of cardiovascular disease, diabetes, weight problems, and breast cancer in women.
Researchers’ extensive review began with studies as long ago as 1967, including more than approximately 200 studies measuring sleep and mental functioning. Participants ages 18 to 29 were categorized as young; ages 30 to 60 as middle-aged; and older than 60 as old.
Participants were asked how many hours they typically slept, how long it takes them to go to sleep, how often they wake in the middle of the night and how sleepy they feel during the day. The research also correlated results from numerous brain-wave studies and experiments dealing with sleep deprivation, napping and sleep intervention, such as sleep medications.
The biggest, most dramatic change in our deep sleep and satisfaction with sleep takes place as we move from adolescence into young adulthood.
“Most adolescents feel like they sleep terrifically, and if you try to wake them up, you’re not even sure they’re alive,” says Robert Simpson, MD, assistant professor in the University of Utah’s division of pulmonary medicine and a sleep medicine specialist. “That’s because they have lots of what we call deep, slow-wave sleep.”
Sleep is broadly split into two big categories: REM (rapid eye movement) sleep, when we’re dreaming, and non-REM sleep. Non-REM sleep moves through several, progressively deeper stages:
Stage I: a light doze, not very restorative
Stage II: middle sleep, restorative
Stage III: slow-wave deep sleep, the most restorative of all
“There’s a fairly precipitous decline in deep slow-wave sleep through the teen years into the early 20s,” Simpson says. “That tends to be replaced with middle sleep, stage II.”
Scullin noted that if a person lives 85 years, he or she may sleep nearly 250,000 hours - more than 10,000 full days.
“People sometimes disparage sleep as ‘lost’ time,” he said. But even if the link between sleep and memory lessens with age, “sleeping well still is linked to better mental health, improved cardiovascular health and fewer, less severe disorders and diseases of many kinds.”
Better Health, Better Sleep
As your health improves, your sleep improves - and vice versa.
“There’s a strong bidirectional relationship between sleep and health,” Simpson says. “That’s particularly true of heart conditions like high blood pressure, stroke, heart attack, and heart failure.”
The amount of sleep adults get in general has been declining over the past few years.
“If you look at the 1960s and 1970s, people reported average sleep times of 8-8.5 hours a night,” Simpson says. “Today, it’s much more likely to be 7-7.5 hours or less.”
Chalk it up to the pace of modern life.
“We lead these frantic lives and we have busy jobs and kids and soccer practice,” Simpson says. “Sleep is what tends to get left out, but that has a lot of ramifications for our overall health.”
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*Study co-author is Donald Bliwise, Ph.D., professor of neurology at Emory University School of Medicine.
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Baylor University
Journal
Perspectives on Psychological Science
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Terry Goodrich
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254-710-3321