How circadian rhythms work.
Our sleep-wake cycle would normally follow the sun. As the sun rises and the temperature gets warmer we wake up. As the sun sets, core body temperature falls, and we produce a hormone called melatonin to promote sleep. This daily cycle is known as our circadian rhythm, this is managed by the master clock in the brain called the suprachiasmatic nucleus (SCN). Located in the hypothalamus, the SCN tells our body when to sleep, when to eat, and when to be the most active, based on cues such as light and temperature.
Circadian rhythms change throughout our lifetime, from middle age they shift half an hour every decade. This change means from 60 to 65 we perform mental tasks better in the morning and start to become sleepy in the late afternoon. There has been research that has shown circadian rhythm timing in older adults, can be more delicate, often leading to disrupted sleep if they do not sleep within certain times..
Two reasons circadian rhythms change with age.
- Studies on mice have shown that the SCN becomes weaker with age. This leads to less pronounced fluctuation in our circadian rhythm, which in turn will produce less melatonin at night, hence older adults may have less of a distinction between being asleep and awake, resulting in sleeping less soundly at night and experiencing more tiredness throughout the day.
- Light is the critical part in regulating our circadian rhythms. There have been many studies researching how light exposure changes as we age. As our eyes age, they do not let as much light in, also we may spend more time in weak artificial light, which is not as effective at regulating our circadian rhythm. After people have had cataract surgery, they often report better sleep, because more light is getting into the eyes.
Coping with these changes.
Older people still need the recommended 7-9 hours sleep. Sleep deprivation can make you tired, confused, and even depressed, symptoms which may be mistaken for dementia or other disorders. While it’s normal to experience sleep problems as you age, severe changes to your circadian rhythm may be an early sign of Alzheimer’s disease. Also, during deep sleep, toxins are flushed from the brain particularly the amyloid plaque. Amyloid plaque build-up is a cause of Alzheimer’s disease.
It is very hard to fight the natural cycles of our bodies, although we all try. If it is possible to change your sleeping pattern to an earlier time, you may have more sound sleep and get more deep sleep. Going to bed and waking up at the same time each day is also helpful.
Getting more light during the day may help you sleep better. If you are a night person try not to get too much light in the morning hours, take your walk or time in the sun in the evening. You could also use light therapy later in the day. This may help delay the melatonin release and make your body think your bedtime is later.
I will begin a course of meditations to help people sleep starting 12th January 2023 at 8pm. Cost £35 if paid on or before the 12th of January or £10 per session.
In the new year I will also have a course you can buy to help with sleeping.