Low-calorie diets slow down the aging process as much as quitting smoking

NEW YORK — Low-calorie diets could slow down the pace of aging and have as much of an impact on health as quitting smoking, a new study suggests. Researchers at Columbia University say eating less calories slows down the aging process by two to three percent. This translates to a 10 to 15-percent drop in a person’s risk of premature death — the same as giving up cigarettes.

The trial involved 220 healthy, non-obese men and women from three sites across the United States. As part of the CALERIE™ intervention, study authors put some of the participants on a 25-percent calorie restricted diet, while the others followed a normal diet. Each person had to adhere to their given diet for two years.

The team measured their aging pace by testing their blood DNA methylation using an algorithm called DunedinPACE. Researchers measured blood samples before participants started their diet and then later on after 12 and 24 months.

“Humans live a long time,” explains Dr. Daniel Belsky, an associate professor of epidemiology at Columbia Mailman School and a scientist with Columbia’s Butler Aging Center, in a media release. “So it isn’t practical to follow them until we see differences in aging-related disease or survival. Instead, we rely on biomarkers developed to measure the pace and progress of biological aging over the duration of the study.”

Dieting alters a person’s biological clock

The team analyzed methylation marks on DNA extracted from white blood cells. These marks are chemical tags on the DNA sequence that regulate the expression of genes and are known to change with aging. At first, the researchers focused on three measurements of the DNA methylation data, sometimes known as “epigenetic clocks.”

The first two, the PhenoAge and GrimAge clocks, estimate biological age or the chronological age at which a person’s biology would appear “normal.” They can provide a measure of how much aging a person goes through.

The third measure estimates the pace of aging and biological deterioration using the DunedinPACE algorithm, also known as a “speedometer.”

“In contrast to the results for DunedinPace, there were no effects of intervention on other epigenetic clocks,” notes Calen Ryan, PhD, a research scientist at Columbia’s Butler Aging Center and co-lead author of the study. “The difference in results suggests that dynamic ‘pace of aging’ measures like DunedinPACE may be more sensitive to the effects of intervention than measures of static biological age.”

“Our study found evidence that calorie restriction slowed the pace of aging in humans,” Ryan continues. “But calorie restriction is probably not for everyone. Our findings are important because they provide evidence from a randomized 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.”

Low-calorie diets also help stave off disease

A follow-up of trial participants is now ongoing to determine if eating less calories could have a long-term effect on healthy aging. Other studies have shown that the slower DunedinPACE, the lower risk of heart disease, stroke, disability, and dementia.

“Our study of the legacy effects of the CALERIE™ intervention will test if the short-term effects observed during the trial translated into longer-term reduction in aging-related chronic diseases or their risk factors,” says Sai Krupa Das, a senior scientist and CALERIE investigator who is leading the long-term follow up of CALERIE™ participants.

“In worms, flies, and mice, calorie restriction can slow biological processes of aging and extend healthy lifespan” Dr. Belsky concludes. “Our study aimed to test if calorie restriction also slows biological aging in humans.”

The results are published online in the journal Nature Aging.

South West News Service writer Mark Waghorn contributed to this report.