Why People Wake Up Earlier With Age: Researchers Explain Sleep Changes
Ageing changes how the brain responds to body-clock signals and how much light the eyes receive, so people often feel sleepy and wake earlier. Experts advise staying in brighter surroundings in the evening and seeing a doctor if constant tiredness persists.
The ability to sleep in gradually fades with age, and the cause is not only habit but also natural changes in the ageing body. The Latvian portal NRA reports this, citing HuffPost. The times when the body naturally wants to go to sleep and wake up are shaped by both genetics and the ageing process.
Cynthia Lustig, a psychology professor at the University of Michigan, says there is no single cause, as all the factors are interconnected.
Brain signals and vision
With age, the brain becomes less sensitive to the signals that help regulate the sleep-wake rhythm. These signals relate to sunlight, sunset, meals, physical activity and social interaction. The nervous system that passes them to the brain may also work less well, so older people often get tired and wake up earlier than their children or grandchildren, explains Sai Ram Parthasarathy, director of the Sleep and Circadian Research Center at the University of Arizona Health Sciences.
Vision changes matter too. They can reduce the amount of light reaching the brain through the eyes, and light helps regulate the body's internal clock. This is especially pronounced in people with cataracts, an eye condition that causes blurred vision. The brain may conclude that sunset has already arrived and start producing melatonin, a hormone that helps prepare the body for sleep, earlier. Studies suggest cataract surgery can improve sleep quality and duration for some people.
What experts recommend
To sleep later, experts suggest paying attention to evening light: spending time in a sufficiently bright environment from about 30–60 minutes before sunset and after it, for example by walking outdoors or brightening lights at home. The aim could be about two hours of bright light. Responses vary from person to person.
Lustig advises avoiding alcohol before bed, as it worsens sleep quality, while regular physical activity and morning sunlight help keep the body clock more stable.
If waking early comes with constant daytime tiredness or difficulty getting enough sleep, it is worth consulting a doctor.
