Why does sleep become more elusive as we age? It has to do with shifts in "sleep architecture"

From salon.com

By Mary Elizabeth Williams

Insomnia and fatigue can worsen with time, but it doesn't have to be complicated to find decent rest

In his later life, my father-in-law routinely woke up for the day at 3 a.m. He'd become such an early bird that he morphed into a night owl, a man resigned to a post-retirement inability to clock in more than four or five hours of rest. I can recall taking his routines as a grim prophecy. And when a few years later I found myself struggling with brutal bouts of insomnia, I wondered if, along with laugh lines and macular degeneration, sleeplessness was an inevitable part of growing older for me, too.

There is a persistent folk wisdom that older people simply don't need as much sleep — an idea likely borne out of the idea that as our lifestyles ostensibly become less active, our requirements for the reparative benefits of rest diminish. As recently as 2008, a report in Current Biology found that in one experiment, older subjects got 1.5 hours less sleep on average than their younger counterparts. "The most parsimonious explanation for our results," researcher Elizabeth Klerman of Brigham and Women's Hospital & Harvard Medical School said at the time, "is that older people need less sleep."

But what we need and what we actually get are two entirely different entities — and we are in the midst of a sleep shortage that's affecting Americans across all generational lines. The CDC notes that "A third of US adults report that they usually get less than the recommended amount of sleep." It's a crisis that can wreak havoc on our physical and mental health, with sleep deprivation contributing to obesity, hypertension, diabetes, depression and stroke. And even accounting for fluctuations among different age populations, most adults need between 7 and 9 hours of sleep per night. The key is just staying in a healthy range. 

Dr. Ryan Sultan, a board-certified psychiatrist, therapist, researcher and professor at Columbia University, says that "As we age, the amount of sleep needed tends to decrease. Older adults may be well-rested and alert after 6 to 7 hours."

My late father-in-law may not have had much steam in him after dinnertime, but his days were as active and engaged as his solitary predawn hours. Sultan says it's just about paying attention to overall health patterns and any changes that feel off. "In my clinical experience," he says, "I have observed that older adults often face unique challenges, such as medical conditions or medications affecting sleep. Addressing these factors with a healthcare professional is crucial for developing a tailored approach to sleep improvement."

As Sultan puts it, "The concept of normal sleep does change as we age, and recognizing these shifts is essential for maintaining optimal health."

The real culprit to watch out for as we age isn't the amount of sleep, but quality of it. Older people have unique vulnerabilities around getting a deep, steady rest. A 2017 analysis in the journal Sleep Medicine Clinics explained how so-called "sleep architecture" can change with age, including "advanced sleep timing, shortened nocturnal sleep duration, increased frequency of daytime naps, increased number of nocturnal awakenings and time spent awake during the night, decreased slow wave sleep, and other changes."

Auckland sleep psychologist Dan Ford, clinical director of the Better Sleep Clinic, puts it simply, "Generally speaking, sleep ability declines as we age as the mechanisms that control sleep become less robust over time." But nothing is set in stone. He adds, "Healthy older adults do not necessarily show these changes in their sleep parameters."

Why do those gorgeous, lengthy sleeps of our younger years become so elusive as we age? There are a whole litany of reasons. There's menopause, with its discomforts and night sweats. Bathroom issues can likewise keep a person of any gender up and down all night long. Changes in the urinary tract, along with other factors like bladder obstruction, make nocturia (frequent night-time urination) far more common in adults over the age of 60.

There are other physical factors as well — the National Council on Aging estimates that " 56% of people age 65 and older have a high risk of developing obstructive sleep apnoea." Our circadian rhythms also change as age, edging us to what can make us feel like we're living in a different time zone from our family and friends. And then there are the mental health issues. Grief, loneliness, financial loss and other stressors can wreck a good night's rest, and the symptoms of depression and anxiety often go undiagnosed. A 2018 study on insomnia in the Journal of Clinical Sleep Medicine found that "As many as 50% of older adults complain about difficulty initiating or maintaining sleep."

So if you're noticing that your nights now typically involve periods of wakefulness, is playing a little catch up when possible during the day a good idea?

"Napping can be a helpful strategy for older adults," says Dr. Ryan Sultan, "but the timing and duration matter. Short naps of around 20 to 30 minutes can boost alertness without interfering with night-time sleep. However, extended or late-afternoon naps might disrupt the sleep-wake cycle, making it harder to fall asleep at night." Mileage can vary even there, though — I have a friend in his late 50s who regularly konks out before making dinner. He calls it a "nappetizer."

For those who have a hard time resisting longer naps, Rod Mitchell, a Calgary psychologist with expertise in cognitive behavioral therapy for insomnia, recommends offsetting grogginess with a "coffee nap." He says, "Combine a small, controlled intake of caffeine (such as a half cup of coffee) followed by a short, 20-minute nap. This method can enhance the restorative effect of napping, with the caffeine kicking in just as you wake up, potentially offering a more refreshing experience." 

However many candles may be on your own next birthday cake, we all need to prioritize adequate rest. We know that building healthy routines like regular bedtimes, avoiding too much caffeine and late-night doomscrolling or binge-watching and getting adequate physical activity are the best bet for a better night — even if it's all easier said than done. Our culture typically regards aging as a failure and sleep as for the weak. But the plain fact is that our bodies change over time. That doesn't mean that once you hit your AARP era,  you suddenly can function just fine on 5 hours of sack time. Instead, if you want to feel younger, you just might actually need to sleep more.

https://www.salon.com/2023/12/02/why-does-sleep-become-more-elusive-as-we-age-it-has-to-do-with-shifts-in-sleep-architecture/