Why does sleep become worse as we age?

As humans age, it becomes increasingly difficult to fall and stay asleep. This can be attributed to a number of different factors that occur naturally as the body ages. According to Dr. Abhinav Singh, medical director of the Indiana Sleep Center, it can be helpful to think of our ability to sleep as a car. As the car ages and accumulates more miles, it begins to fall apart, requiring more repairs and becoming less smooth to drive. Similarly, as aging occurs, sleep quality begins to deteriorate.

Research has shown that older adults tend to take longer to fall asleep, wake up more frequently throughout the night, and spend more time napping during the day when compared to younger adults. Additionally, older adults spend less time in deep, restorative sleep, which is essential for maintaining physical and mental health. This includes promoting bone and muscle growth and repair, strengthening the immune system, and helping the brain reorganize and consolidate memories. Melatonin levels, which play a crucial role in regulating the sleep-wake cycle, also decrease with age, further contributing to sleep disturbances.

These changes in sleep patterns are supported by research, as a study from 1995 found that 57% of people ages 65 and older reported at least one sleep complaint over a three-year period. These complaints included difficulty falling or staying asleep, waking up too early, feeling unrested, and napping during the day. In a separate study from 2014, researchers found that over half of older adults surveyed had either one or two insomnia symptoms in the past month.

Additional research suggests that women may be more likely than men to report poor sleep quality and that sleep disruptions may occur earlier in life for women, particularly during the menopausal transition, which typically begins between the ages of 45 and 55. The exact cause of these changes is not fully understood, but it is thought to be related to changes in the brain and the body.

Studies in mice have also found that certain clusters of neurons responsible for wakefulness become overly stimulated in aging mice, disrupting their sleep cycles. It is believed that a similar process occurs in humans, as the part of the brain that regulates sleep in mice, the hypothalamus, is similar to that in humans. Additionally, researchers have found that the suprachiasmatic nucleus, another brain region that regulates the body's circadian rhythms, deteriorates in mice with age, leading to sleep disorders.

Lifestyle changes can also contribute to sleep disruptions later in life. As people retire, their days may become less structured and routine, leading to the development of habits such as sleeping in, napping during the day, and difficulty falling asleep at night. Factors such as depression, loneliness, and grief can also impact sleep in older adults. Additionally, for women, symptoms of menopause such as hot flashes, night sweats, and higher rates of depression, anxiety, and stress may also be correlated with poor sleep.

While the exact causes of these changes are not fully understood, certain habits such as maintaining a consistent sleep schedule, avoiding caffeine, following a healthy diet, and exercising regularly can improve sleep quality for older adults. Additionally, older adults who are on medications should check with their doctors about whether the drugs might be interfering with their sleep and if there might be alternative options or a different dosage.

References:

Gupta, A. H. (2022, December 27). Why Does My Sleep Become Worse as I Age? The New York Times. Retrieved January 18, 2023, from https://www.todayonline.com/world/why-does-my-sleep-become-worse-i-age-2086511