32 Snooze Your Way to a Younger Brain
You probably don’t need a study to tell you that not getting enough sleep can make it hard to think clearly and remember things. But research does show that sleep deprivation can affect cognition, and since your sleep patterns change and your risk of sleep problems increases as you get older (
19), not getting enough shut-eye can aggravate age-related cognitive decline. A 2009 study by Israeli researchers found that older adults with chronic insomnia (a common late-life complaint) scored much worse on cognitive tests measuring memory span, attention, time estimation, working memory (retaining recently learned information), and integration of two dimensions than those without sleep complaints. Ultimately, the researchers suggested, improving sleep may help maintain cognitive function in older adults.
Sleep is critical for memory formation and recall because it consolidates and encodes memories in your brain to make them easier to retrieve when you’re awake. Declarative memories (facts, or things you consciously remember and can explain in words) are most affected by slow wave sleep, the first stage of deep sleep. Rapid eye movement (REM) sleep is the second stage of deep sleep, when dreams generally occur, and it benefits procedural (skill-based) and emotional memory. And while mental fatigue is obvious after an all-nighter, research shows that gradually accumulating a sleep debt might even be more harmful because you’re less likely to notice the resulting cognitive decline. A 2003 study in the journal Sleep found that people who consistently got six or fewer hours of sleep per night for two weeks scored just as poorly on cognitive tests as those who experienced two nights of total sleep deprivation. What’s more, after a few nights of limited sleep, the volunteers didn’t feel sleepier during the day or realize that their cognitive performance was gradually getting worse. The takeaway, researchers wrote, is that “even relatively moderate sleep restriction can seriously impair waking neurobehavioral functions in healthy adults.”
Another sneaky brain-sapping side effect of sleep deprivation is its link to depression (30). Older adults are more likely to experience both depression and sleep problems, and while researchers aren’t sure if depression leads to sleep problems or vice versa, they acknowledge it’s easy to sink into a self-perpetuating cycle of the two. Conversely, improving sleep or treating depression can benefit both conditions and lead to better brain function.
Get More Zzzs to Keep Your Brain in Top Shape
If you have a chronic sleep problem, like insomnia, restless legs syndrome, or obstructive sleep apnea (all of which are more common as you get older), talk to your doctor or a sleep specialist to design a treatment plan. Certain health conditions or medications may trigger sleep problems as well; work with your doctor to get health issues under control or switch medicines if needed.
If health problems aren’t interfering with your sleep, there are some easy ways to ensure a good night’s rest. Start by determining how much sleep you actually need (most people over fifty require between seven and nine hours a night). Try going to bed at a consistent time and letting yourself wake up naturally without an alarm for a full week, without napping during the day if possible. At the end of the week, in theory, you will have made up for a good portion of your sleep debt and should be able to determine your nighttime sleep needs. Once you know how much you need, you may find you have to alter your bedtime routine in order to get the full amount. Lifestyle changes like setting a regular sleep schedule and keeping your bedroom dark can help you fall and stay asleep (19, 63). If you need help getting drowsy for an earlier bedtime, about an hour beforehand dim the lights and switch to quieter activities, like reading a lighthearted book or meditating. Taking a hot bath or shower before bed also helps by raising your core body temperature—once you’re out of the hot water, the resulting temperature drop allows you to fall asleep faster and sleep more soundly. Avoid drinking alcohol or consuming caffeine for three to four hours before bed, and if you still have trouble sleeping, cut them out completely. If an overactive mind is keeping you awake, stash a notebook on your nightstand to write down concerns or tomorrow’s to-do list and try a mind-body technique like progressive muscle relaxation (31) to help quiet your mind. If you’ve tried all these lifestyle changes and are still having trouble sleeping, consider taking melatonin or another natural remedy (63). Prescription sleep aids can also be effective, but they carry greater risks of potentially serious side effects and may be habit-forming—use them as a last resort.