Saturday/Sunday October 14-15, 2017 | Wall Street Journal | Matthew Walker
As you may painfully know: Sleep gets more difficult the older you get.
Older adults are less able, on average, to obtain as much lder adults are less able, on average, to obtain as much sleep, or as restorative a sleep, as young adults. The problem gets so bad that by our 80s, the lack of sleep can have major health ramifications, though we do not always notice.
Older adults face a number of challenges. The first is a reduction in the quantity and quality of deep sleep – the stage that beneficially overhauls your cardiovascular, immune and metabolic systems and refreshes learning and memory abilities. As you enter your 30’s and 40’s, your deep sleep brain waves become smaller, less powerful, and fewer in number. Reductions in deep sleep quality increase your risk of heart attacks, obesity, and stroke – as well as the buildup of a toxic brain protein – called beta-amyloid which is linked to Alzheimer’s disease.
Passing into your mid to late 40’s, age will have stripped you of 60% to 70% of the deep sleep you were enjoying as a teen. By the time you reach 70, you will have reached 80% to 90% of your youthful restorative deep sleep.
The second hallmark of altered sleep as we age is called fragmentation.
The older we get, the more frequently we wake up through the night. Causes include body pain and a weakened bladder. Reducing fluid intake in the evening can help reduce the latter, but is not a cure-all.
Because of sleep fragmentation, older people will suffer a reduction in sleep efficiency, defined as the percent of time you were asleep while in bed.
Most sleep doctors consider good quality sleep to involve a sleep efficiency of 90% or better. By the time we reach our 80’s, sleep efficiency has often dropped below 80%. That means that within an 8-hour period, you have spent an average of 1.5 hours being awake.
Inefficient sleep is no small thing.
The lower an older individual’s sleep-efficiency score, the higher the higher their mortality risk, the worse their physical health and the lower their cognitive function, typified by forgetfulness.
The third sleep change with advanced age is that of circadian timing – the body’s internal clock that times our sleep-wake rhythms. Seniors commonly experience a regression in circadian timing, leading to earlier bedtimes. The cause is an early release and peak of melatonin in older adults in the evening, instructing an earlier start time for sleep, in part because of an early drop in core temperature.
Changes with circadian timing with advancing age may appear harmless, but they can be the cause of numerous sleeping (and waking) problems in the elderly. Older adults often want to stay awake later into the evening but often find themselves inadvertently falling asleep. Accidental evening snoozes release otherwise healthy sleep pressure that builds in the daytime. Irrespective of how old you are, those unplanned naps will make it harder to sleep at night.
A compounding problem arrives int he morning. In many elderly individuals, their circadian rhythm will start to rise around 4 am – 5 am, even if they had trouble falling asleep the night before. A self-perpetuating cycle ensues wherein many seniors are battling a sleep debt.
Older adults may wish to consult with their doctor about taking melatonin in the evening. Prescription melatonin can help boost the otherwise blunted circadian and associated melatonin rhythm in the elderly, improving sleep regularity and thus quality.
Many seniors progress through their later years not realizing how much their sleep has degraded. This means that elderly individuals fail to connect their deterioration in health with their deterioration in sleep. Not all medical problems of aging are attributable to poor sleep. Bur far more of our physical and mental health ailments are related to sleep impairment that either we or many doctors, truly realize or treat seriously.