How old are you inside? Tiny tweaks to rewind your body clock

We can’t turn back the years, but by making the right lifestyle choices, it’s possible to reverse our biological age

We can slow or even reverse chronological ageing through diet and exercise. Picture: iStock

How old are you inside? We celebrate our chronological age with birthdays, but our bodies age biologically as damage to cells and tissues accumulates.

A range of age-related biomarkers, from blood pressure, lung capacity, and grip strength to the length of one’s telomeres (the ‘bumpers’ that protect DNA from damage), determines our ‘biological age’.

People can be biologically 12 years older or younger than their chronological age. “Depending on what their previous years looked like and how they lived their lives, we can see people aged 37 with a biological age of either nearer to 50 or as youthful as someone in their 20s,” says Rose Anne Kenny, professor of medical gerontology at Trinity College Dublin and lead researcher on the Irish Longitudinal Study on Ageing (TILDA).

Just as bad lifestyle can accelerate this inner age, a healthy diet and exercise can decelerate it.

We can slow or even reverse chronological ageing through diet and exercise. “We are seeing that in people who do change their lifestyle habits for the better, there is an intracellular effect on the biological clock,” Kenny says. “The earlier in life the changes are made, the better, but even in older people you can stall biological ageing.”

The tiniest tweaks to your daily habits could have profound benefits. “It’s the little things that make a difference, so don’t get overwhelmed,” Kenny says.

“I suggest people try one new thing a month, such as reducing their sugar and ultra-processed foods intake in month one, doing a little bit more daily activity in month two, and aiming to stand up and move every 45 minutes in month three.”

Here are other steps to take:

Drink three cups of tea a day

Tea-drinking has long been known to be good for us, but a 2024 study on its benefits published in The Lancet suggests that three cups a day could slow down biological ageing.

Scientists analysed the tea-drinking habits of almost 8,000 adults from Europe and China. They measured various biomarkers, including blood pressure, cholesterol, and body fat, to determine their biological age — an estimate of how well they are ageing at a cellular level, instead of chronologically.

Daily drinkers of black and green tea showed signs of slower biological ageing, and for those who consumed three cups a day the benefits were marked. Moderate tea consumption had the strongest anti-ageing benefits among consistent tea drinkers.

People who stopped drinking tea when the study was over appeared to show accelerated biological ageing, so it’s important to keep up the habit.

Try a 20-minute workout (and eat more protein)

For a study in the journal Age and Ageing last year, researchers from University College Dublin found that a short, home-based workout, paired with a protein-rich diet, not only enhanced physical resilience, but reduced the biological age of participants.

Some participants were asked to do 20 minutes of daily activity at least four times a week, but preferably every day, in the form of 10 exercises that strengthened arms and legs and improved balance and co-ordination.

They were also asked to walk, swim, or cycle for 30 to 45 minutes three to four times weekly, and to eat more protein in the form of milk, eggs, tuna, chicken, or via plants, such as beans and lentils, to improve muscle health.

A control group made no activity or dietary changes.

After three months, the workout group was biologically seven months younger, while the control group had aged biologically by three months.

“It was an encouraging and significant finding, but more research needs to be done on biological ageing,” says Dr John Travers, a Dublin-based GP who led the study.

Go running five times a week

Pic: iStock

Aerobic exercise has potent benefits for longevity, provided it is done regularly. But researchers at Brigham Young University suggest that more effort slows ageing inside the body’s cells.

In the study of 5,000 adults who were either highly active, moderately active, or sedentary, researchers compared the length of their telomeres.

As we grow older, our telomeres shorten, a process compounded by poor diet, smoking, drinking, and inactivity, and this results in accelerated cell ageing. However, highly active runners were found to have the longest telomeres and were biologically nine years younger than the sedentary group, and seven years younger than even the moderately active people.

Pick up your walking pace

Walking at a brisk pace of 100 steps per minute (or 2.7mph) could add years to your life. 

Thomas Yates, a professor in physical activity, sedentary behaviour and health at the University of Leicester, and his team found that, compared with slow walkers, fast walkers live an average of 20 years more.

For a follow-up trial, they studied 400,000 middle-aged adults in Britain to find whether longer telomeres enabled people to walk more briskly or if walking briskly was the reason their telomeres were longer.

They discovered that faster daily walkers have a biological age 15 years younger than dawdlers.

“We found a casual association, meaning it was the quick walking pace that led to people having a quite significantly younger biological age,” Yates says. “It really can take biological years off your life.”

Get a good night’s sleep

Too much or too little sleep increases inflammation and susceptibility to age-related diseases. Seven to nine hours is the optimal target for sleep. Poor sleep, even for one night, accelerates the biological ageing of cells.

Judith Carroll, assistant professor of psychiatry and biobehavioural science at UCLA, subjected a group of people aged over 60 to different sleep patterns over four nights, including one night when they were allowed only four hours of sleep, from 3am to 7am.

Blood samples revealed that a single night of insufficient sleep caused changes to DNA. “One night of not getting enough sleep in older adults activates important biological pathways that promote biological ageing,” Carroll says.

Take up yoga

Yoga can make you feel more youthful, by improving flexibility and mobility, but it can also slow physical ageing by reducing the harmful effects of stress at a cellular level.

Twelve weeks of yoga that included postures, breathing techniques, and meditation for 90 minutes up to five days a week was shown in a 2017 study to slow key markers of cellular ageing in the bodies of 96 people.

There were positive changes in biomarkers that indicate DNA damage and oxidative stress that can age cells and telomeres.

This article was first published on April 12, 2024.