Cutting calories may make you younger, a study suggests. Researchers looked at 220 people — a third of whom cut their calorie intake by 25 percent over two years — while the rest ate normally.
The calorie-cutters appeared to age up to three percent more slowly – which could slash their risk of an early death by as much as quitting smoking, the authors claim.
It is well known that cutting calories makes people who are obese healthier through losing weight. But this is the first long-term study of calorie cutting in healthy, non-obese people.
It backs up previous studies in mice and rats that showed cutting calories is one of the best ways to achieve the holy grail of a longer, healthier life.
Cutting calories may make you younger, a study suggests – and it’s not too late to start in middle-age
It was possible to see dieters aging more slowly using a cutting-edge blood test only created in the past decade.
The test was developed using signs of aging like higher blood pressure and cholesterol, which were tracked in hundreds of people from age 26 to 45.
These signs of aging were matched with genetic activity in the body. This genetic activity alone was then used to judge how fast someone is aging in the final blood test.
Dr Daniel Belsky, who led the study from Columbia University Mailman School of Public Health in New York, said: ‘This study is very exciting because we found calorie restriction can reduce the pace at which people age biologically.
‘Slowing down biological aging means living longer and getting ill later.
‘Therefore calorie restriction may not just benefit people who are obese, but could give healthy people longer, healthier lives.’
The research, published in the journal Nature Aging, looked at people from New Zealand who were helped to cut calories with weekly weight loss sessions in a previous study.
The volunteers started with 27 days of meals in smaller portions, which they were provided, then continued dieting alone, typically losing 15 percent of their weight in the first year.
Not everyone achieved the target of cutting calories by 25 percent.
But analysis of the dieting group as a whole found they aged two to three percent more slowly than people eating as normal.
Those who cut calories by more than 10 percent appeared to benefit most, aging about one per cent more slowly than those who cut their calorie intake by less.
The study used three tests of biological age, which all look at genetic activity called DNA methylation – the ‘epigenetic’ changes in cells which work like a dimmer switch to dial gene activity up or down.
DNA methylation in blood cells from blood tests shows whether people are aging at a typical rate, and can indicate signs of aging like rising blood pressure and a less effective immune system.
Calorie-cutting was only found to be beneficial using one of the tests – the DunedinPACE test of biological aging.
The study authors say this is because two of the tests are snapshots of biological age, rather than measuring people’s rate of aging over time.
A two to three per cent slower rate of aging means a 10 to 15 per cent lower risk of early death, previous studies suggest.
Therefore, the authors say, the two-year calorie cutting diet could have the same effect on someone’s risk of dying early as has been seen in studies where people gave up smoking.
Dr Calen Ryan, co-lead author of the study, from Columbia University Mailman School of Public Health, said: ‘Calorie restriction is probably not for everyone. ‘Our findings are important because they provide evidence from a randomised trial that slowing human aging may be possible.
‘They also give us a sense of the kinds of effects we might look for in trials of interventions that could appeal to more people, like intermittent fasting or time-restricted eating.’
A follow-up of trial participants is now ongoing to determine if people on the low-calorie diet do in fact go on to lead longer, healthier lives, as their blood tests suggest.