As we grow old, our nights are frequently plagued by bouts of wakefulness, bathroom trips and other nuisances as we lose our ability to generate the deep, restorative slumber we enjoyed in youth.
But does that mean older people just need less sleep?
The UC Berkeley researchers have argued in an article published in the journal Neuron that the unmet sleep needs of the elderly elevate their risk of memory loss and a wide range of mental and physical disorders.
"Nearly every disease killing us in later life has a causal link to lack of sleep," said the article's senior author, Matthew Walker, a UC Berkeley professor of psychology and neuroscience. "We've done a good job of extending life span, but a poor job of extending our health span. We now see sleep, and improving sleep, as a new pathway for helping remedy that."
Unlike more cosmetic markers of aging, such as wrinkles and gray hair, sleep deterioration has been linked to such conditions as Alzheimer's disease, heart disease, obesity, diabetes and stroke, he said.
Moreover, the shift from deep, consolidated sleep in youth to fitful, dissatisfying sleep can start as early as one's 30s, paving the way for sleep-related cognitive and physical ailments in middle age.
And, while the pharmaceutical industry is raking in billions by catering to insomniacs, Walker warns that the pills designed to help us doze off are a poor substitute for the natural sleep cycles that the brain needs in order to function well.