Recently, despite my better judgment and everything I know about the health and wellness, I stayed up all night working to meet a deadline. The following day was a blur. Every little thing was more difficult than usual. I was irritable with my loved ones and had trouble making decisions — even simple ones, like what to eat.
It got me thinking back to my college years, when all-night studying, paper writing, and socializing were not uncommon. Sure, the next day was a little rough, but I could handle it well enough to pull all-nighters fairly regularly. So why has my reaction to sleepless nights changed so drastically as I’ve gotten older?
Turns out, a couple new studies indicate that inadequate or low-quality sleep becomes increasingly detrimental to cognitive functioning as we get older – contributing to the likelihood of developing dementia and Alzheimer’s disease.
The Importance of High-Quality Sleep
As part of a study on aging issues, researchers in the UK analyzed the sleep patterns of nearly 9,000 men and women, and found that sleep quality and quantity is critically important as we age. Interestingly, the importance of quality versus quantity of sleep appeared to vary among age groups.
The team from the University of Warwick determined that getting between six and eight hours of sleep was optimal for pre-retirement adults (ages 50-64). Too little or too much sleep, however, and this age group showed lower brain function scores.
For older adults (ages 65-89), quantity became less important – only those who slept more than eight hours showed lower cognitive abilities. But although shorter sleep duration didn’t impact the cognitive wellness of this age group as much as it did the younger adults, the quality of sleep still proved to be very important. Older adults who got restful, restorative sleep suffered less cognitive decline than those who didn’t.
This appears to be true on an international scale. Also last month, University of Oregon researchers published a study that considered the sleep habits of 30,000 individuals aged 50 and older worldwide, and found that those who slept six to nine hours per night had higher cognitive scores than those who did not. The researchers focused on six very different countries – China, Ghana, India, Mexico, Russia, and South Africa.
“In all six countries, which are very different culturally, economically and environmentally … you see similar patterns emerging,” said study lead author Theresa E. Gildner.
Researchers for both recent studies had the same takeaway: Good sleep matters – a lot.
“Sleep is something that is important but often undervalued in our society,” said University of Oregon researcher Josh Snodgrass. “Every single piece of evidence that people look at now as they are investigating sleep and different health associations is all showing that sleep really, really, really matters.”
And according to Cappuccio of the University of Warwick study, “Sleep is important for good health and mental well-being. Optimizing sleep at an older age may help to delay the decline in brain function seen with age, or indeed may slow or prevent the rapid decline that leads to dementia.”
Dr. Michelle A. Miller with the University of Warwick concludes that in the wake of these findings, it would be valuable to explore options outside of prescription medication.
“Non-pharmacological improvements in sleep may provide an alternative low-cost and more accessible Public Health intervention, to delay or slow the rate of cognitive decline,” she said.