Research suggests that restricting the number of calories consumed could slow aging in humans.
According to the study, cutting calories by a quarter caused the rate of aging to slow by 2-3%, representing a 10-15% reduction in the risk of death.
This effect is similar to that of quitting smoking, the researchers say.
But experts caution that it’s important to be cautious and not encourage people, especially older people, not to eat less to slow the aging process.
While reduced calorie intake appeared to slow the rate of aging, this did not translate into an increase in estimated life expectancy.
Lead author Daniel Belsky, an associate professor of epidemiology at Columbia’s Mailman School of Public Health and a scientist at Columbia’s Butler Center on Aging, said: “In worms, flies, and mice, caloric restriction can slow the biological processes of aging and prolong healthy life.
“Our study aimed to test whether caloric restriction also delays biological aging in humans.”
In a one-of-a-kind trial, an international team of researchers led by the Columbia Butler Center on Aging at Columbia University’s Mailman School of Public Health found that caloric restriction can slow the rate of aging in healthy adults.
The trial involved 220 healthy men and women at three sites in the US on a normal or 25% calorie-restricted diet for two years.
At baseline, people generally ate just over 2,000 calories per day.
CALERIE, the name of the study, is an acronym for: Comprehensive Assessment of the Long-Term Effects of Reduced Energy Intake.
To measure biological aging, the researchers analyzed blood samples collected at the start of the trial and after 12 and 24 months of follow-up.
Professor Belsky said: “Humans live a very long time, so it’s not practical to follow them until we see differences in disease related to aging or survival.
“Instead, we relied on biomarkers developed to measure the rate and progress of biological aging over the duration of the study.”
The team looked at chemical tags in DNA that regulate gene expression and are known to change with ageing.
Calen Ryan, co-lead author of the study, said: “Our study found evidence that caloric restriction slowed the rate of aging in humans.
“But caloric restriction probably isn’t for everyone. Our findings are important because they provide evidence from a randomized trial that delaying human aging is possible.
“They also give us an idea of the types of effects we might look for in trials of interventions that might appeal to more people, such as intermittent fasting or time-restricted eating.”
The findings are published in the journal Nature Aging.
Dr Duane Mellor, Registered Dietitian and Senior Lecturer at Aston Medical School, Aston University, said: “This is an interesting study that looked at 220 people between the ages of 21 and 50, who were randomly assigned to a 25% energy (calorie) restriction for two years or to eat to your appetite.
“It is difficult to interpret the data in this study, to say how the data reported in this study matched the diets that people actually followed, only that those who were told to eat less were reported to have slightly aged DNA, but significantly slower. .”
He added: “While interesting, it is important to be cautious and not especially encourage older adults to reduce their food intake to slow aging.
“Like, in older adults, maintaining a healthy weight, being physically active, and eating a varied and healthy diet with sufficient protein is known to reduce the risk of falls.”
Naveed Sattar, Professor of Metabolic Medicine at the University of Glasgow, said: “This sounds like well-conducted research on complex markers in the context of a small-scale calorie reduction trial, but do we really need to show that eating fewer calories slows down processes? of aging?
“This should be evident from national data sets showing that people in Japan who remain thinner than most are among the longest living of any nation.”
He added that the findings are in line with “an emerging body of evidence pointing in the same direction.”