Research: maintaining a regular daily rhythm significantly reduces the risk of dementia

There is growing global concern over the continued rise in dementia rates, at a time when an effective cure is still elusive. While much popular advice focuses on brain exercises or nutritional supplements, recent scientific evidence points to one key factor that may play a major role in prevention: maintaining the body’s circadian rhythm – according to a report on the medical website “ScienceAlert”.

Humans are controlled by an internal 24-hour rhythm, known as the circadian rhythm, which regulates sleep and wakefulness, hormone secretion, body temperature and heart rate. Disruption of this rhythm may lead not only to insomnia and fatigue, but also to damage to brain health in the long term.

According to a 2025 study that included more than 2,000 participants with an average age of 79, people who maintained a regular daily rhythm had about a 50% lower risk of developing dementia, compared to those who had a disruption in their biological clock.

During three years of follow-up, only 7% of those with a regular daily heart rate developed dementia, compared to 10% among those who did not maintain such regularity – this after measuring daily heart activity using dedicated devices.

Sleep disorders have long been linked to dementia and heart disease, but experts emphasize that the issue is more complex than just the number of hours of sleep. An update by The Lancet Committee for the Prevention of Dementia stated that sleeping longer or shorter than usual is not an independent risk factor in itself, and that the disruption of the circadian rhythm may have a more significant effect than the sleep duration itself.

Researchers believe that disruptions in the biological clock affect the immune system and weaken the brain’s ability to get rid of toxic proteins, such as the amyloid plaque associated with Alzheimer’s disease – although the evidence regarding this mechanism is still inconclusive.

The simplest prevention key

Amidst the scientific debate, one factor stands out and enjoys broad consensus: regular physical activity. Walking or moderate physical activity for about 30 minutes a day – especially outside and before noon – helps regulate the rhythm of the biological clock, improves the quality of sleep, and at the same time reduces the risk of dementia and heart disease, according to an analysis published on The Conversation website.

Exercise reduces obesity, improves nerve cell health and increases blood flow to the brain – making it one of the most powerful protective factors known today.

While sleep disturbances may sometimes be an early sign of dementia-related brain changes, maintaining a regular lifestyle—including daily exercise, exposure to natural light, and a consistent sleep-wake routine—remains a safe and accessible prevention option for most of the population. In an increasingly stressful and volatile world, regulating the pace of life may be a simple but powerful way to protect the brain as we age.