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There’s some unsettling news for older adults who have significant difficulty falling asleep and experience frequent bouts of insomnia. According to the World Sleep Society, sleep deprivation threatens the health of up to 45% of the world’s population. And by “threatening,” they mean that those older adults who don’t get enough sleep are at high risk for developing dementia or dying early from any cause. 

The study, published in the Journal of Sleep Research, analyzed data collected by the National Health and Aging Trends Study (NHATS), which conducts annual in-person interviews with a nationally representative sample of 6,376 Medicare beneficiaries.

“These results contribute to existing knowledge that sleep plays a very important role, each and every night, for reducing our longer-term risk for neural, cognitive decline and all-cause mortality,” said study author Rebecca Robbins, an instructor in medicine at Harvard Medical School who specializes in sleep research.

Depending on our age, we’re supposed to get between 7-10 hours of sleep each night. But one-third of Americans don’t get enough sleep, according to the US Centers for Disease Control and Prevention.

The CDC calls the fact that 50 million to 70 million Americans struggle with sleep disorders such as sleep apnea, insomnia, and restless leg syndrome, a “public health problem.” The problem is that disrupted sleep is associated with a higher risk of diabetes, stroke, cardiovascular disease — and dementia.

Participants self-reported their sleep difficulties, which were then compared to each participant’s medical records. The NHATS study followed each participant over the span of eight years, analyzing how their sleep patterns fluctuated. This was a strength of the study, Robbins said, because “sleep health can ebb and flow over the years.”

Researchers could also differentiate the impact of having a bit of trouble falling asleep versus frequent nighttime awakenings on any risk of dementia and death.

“We found a strong association between frequent difficulty falling asleep and nighttime awakenings and dementia and early death from any cause, even after we controlled for things like depression, sex, income, education, and chronic conditions,” Robbins said.

Most nights, people who had trouble falling asleep had about a 44% increased risk of early death from any cause, the study found. And those who often woke in the night and struggled to return to sleep had a higher risk — a 56% increased risk of early death from any cause.

People who reported routinely experiencing difficulty falling asleep had a 49% increased risk of dementia, while those who often woke in the night and had trouble falling back asleep had a 39% increased risk of dementia.

People who had problems falling and staying asleep had the highest risk of either dementia or dying early from any cause.

Robbins said, “We found a 56% increased risk of dementia and an 80% greater risk of all-cause mortality over the following eight years among those who experienced both concurrent sleep difficulties — falling asleep or waking from sleep,”

An earlier 2017 study compared dementia markers in spinal fluid against self-reported sleep problems and found that participants who had sleep issues were more likely to show tau pathology, brain cell damage, and inflammation. That was true even when other factors like depression, body mass, cardiovascular disease, and sleep medications were considered. 

Medical science has no current cure for dementia, but there are things you can do to reduce your risk. You know the drill:

  • Don’t smoke
  • Drink only in moderation, if you drink at all 
  • Eat a well-balanced diet, exercise, 
  • Stay mentally active 
  • Keep your blood pressure and cholesterol levels in check
  • Make sure you have good “sleep hygiene” habits — set a bedtime routine designed to relax and soothe — which includes no TV, smartphone, or other blue-light emitting devices at least one to two hours before bed.
  • Have a comfortable bed and pillow, keep the bedroom cool, quiet, and dark, and avoid caffeine and alcohol for hours before bed.

Our takeaway for this research is clear: Sleep is critical. Not only in the short term, but for long-term health. Not sleeping properly has consequences… Whatever it takes, get the sleep your body needs!