We MAY believe that the secret to maintaining youthful health lies in turning back time with “magic” potions and regimens. But scientists now say we can do something much more practical (and promising) by targeting our internal clocks.
Researchers in the US suggest that we can improve our physical and mental health – and even slow down aging – by adopting everyday habits and ensuring that our various internal clocks stay properly synchronized with each other so that they work with each other. work at optimal efficiency.
It has been known since the 1990s that the body has an internal molecular clock that regulates vital functions such as sleep, appetite and metabolism according to a daily cycle. This is called our circadian rhythm or clock.
But there is more than one clock. In fact, in recent years, researchers have discovered that we are absolutely teeming with internal timekeepers.
Circadian clocks are now believed to be present in almost every cell and tissue in our bodies, with a ‘master clock’, the suprachiasmatic nucleus, in the brain.
Researchers in the US suggest that we can improve our physical and mental health by adopting everyday habits to keep our various internal clocks properly synchronized with each other.
It has been known since the 1990s that the body has an internal molecular clock that follows a daily cycle to regulate vital functions such as sleep, appetite and metabolism (Stock Image)
The bad news is that as we age, our circadian timekeepers can become increasingly divergent, according to research from Northwestern University in the US, published earlier this month in the journal Chaos.
It’s like living in a house full of vintage wind-up clocks that all chime at different times. This may mean that vital systems for regulating our body functions and brains no longer work in as healthy sync as they did when we were younger.
Research increasingly links this “circadian clock desynchronization” to serious problems such as cardiovascular disease, obesity, type 2 diabetes and cancer, the Northwestern scientists warned.
Moreover, the damage is not only physical, according to research by biologists from Cleveland State University in the US
In a review published last year in the journal Nature Reviews Neuroscience, they provided evidence that our circadian clock regulates crucial functions, such as our body’s systems for repairing defective DNA, as well as an essential maintenance process called autophagy, which keeps our cleanses the brain of damaged cells. .
The Cleveland researchers warned that circadian rhythms are “significantly affected by aging – and this disorder may contribute to cognitive decline in the aging brain.”
They said that circadian rhythms are “significantly disrupted” in patients with Alzheimer’s and Parkinson’s disease, suggesting that desynchronized clocks may be at least partly responsible for these conditions.
But they added that experiments using rodents with dementia-like symptoms to restore the accuracy of their circadian clocks – getting them all to run on their correct daily schedules – improved the animals’ “cognitive performance” and extended their lifespans.
A report published in February in the journal Nature Reviews Endocrinology suggested that if we can promote better circadian synchronization later in life, it could “effectively slow the aging process” because our bodies will function themselves more efficiently.
Is it actually possible to improve the accuracy of our various biological clocks? Research is beginning to suggest intriguing answers. The Northwestern University researchers pointed out that different circadian clocks rely on different external cues to set themselves each day.
For example, the brain’s clock depends on sunlight, while peripheral organs – such as our liver – calibrate themselves during meals, said Dr Yitong Huang, who led the study.
Eating at the wrong times – such as partying at midnight – can be particularly damaging, she warned: ‘Giving conflicting signals to your internal clocks through late-night eating – eating when your brain is about to rest – can confuse them and cause misalignment between the internal clocks. .’
In contrast, she said, eating breakfast first can effectively tell our metabolism to properly set our clocks at the start of the waking day.
Food intake is a time-setter, says Dr. Kristin Eckel Mahan, associate professor at the University of Texas Center for Metabolic and Degenerative Diseases and lead author of the Nature Reviews report.
She points to laboratory studies that have shown that the timing of food intake drives the synchronicity of the circadian clock.
Other research shows that food can significantly help keep our internal clocks synchronized, but only if we eat almost a third less than the recommended amount – reducing our intake from an overall average of 2,000 calories per day for women and 2,500 for men to 1,400. and 1,750 calories respectively.
Studies in fruit flies have shown that reducing their food intake to 70 percent of their normal needs could extend their lifespan by as much as 40 percent (the equivalent, in humans, of living to 120 years).
Dr. Eckel Mahan says this effect is due to the fact that calorie restriction improves our internal clock synchronization. It helps do this by optimizing the activity of body clocks that reduce harmful inflammation and protect brain cells from damage.
Another reason, she adds, is that dietary restrictions increase the efficiency of body clocks that detect light – and daylight is one of the most important environmental influences when it comes to setting our daily clock rhythm. This can be especially important as we get older.
The new research from Northwestern University shows that a common problem among the elderly is that their biological clock becomes less sensitive to the daily setting of daylight.
Such findings are in line with the work of Russell Foster, professor of circadian neuroscience at the University of Oxford. Numerous studies show that as we age, the lenses in our eyes become less clear and the number of light-sensitive cells in our retina decreases, making us less responsive to light levels.
Professor Foster’s strongest advice is that we should actively go outside and seek daylight to start our days – and set our internal clocks.
He says: ‘Provide morning light. That will strengthen your circadian drives.”
He cites research from nursing homes where patients were exposed to bright light every morning for years. Not only did it reduce both cognitive decline and depressive symptoms, but it also improved their nighttime sleep and reduced daytime sleepiness.
Nevertheless, he adds, sleeping less well as we get older – because our aging internal clocks are more likely to get out of sync – is a problem that will affect most of us.
“In middle age, there’s no point in harking back to the sleep you had in your 20s and 30s as some kind of ideal,” he says. ‘We have to accept that things change and adapt our habits.’