Study: Low-calorie diet improves aging, lowers mortality risk

The benefits of a low-calorie diet may extend beyond just shedding a few pounds. New research shows following a calorie-restricted diet may slow the rate of aging in healthy adults (Nat Aging. 2023;3:248-257).

How food affects health has been a long-time focus for researchers, with ample evidence to suggest that what a person eats can affect how well they age. Drinking coffee on a regular basis, for example, may slow cognitive decline and even protect against Alzheimer’s disease, according to a recent study.

Similarly, blueberries and other colorful fruits and vegetables were found to protect against age-related cognitive decline.

The present study, instead of looking to specific foods or groups of foods, looked at how the impact of a broader dietary change could impact aging. That dietary change, per the Nature Aging study, was a calorie-restricted diet.

The Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy (CALERIE) Phase-2 randomized controlled trial investigated the effects of long-term calorie restriction in healthy adults who were normal weight or slightly overweight. For the study, 220 participants were randomized to either restrict their calorie intake by 25% or follow a normal diet for two years.

The researchers measured the impact of the diets by measuring methylation marks on DNA extracted from white blood cells that were collected from the participants before the trial, and after 12 and 24 months of follow-up. DNA methylation (DNAm) marks are chemical “tags” found on the DNA sequence that are known to change with aging. These tags regulate the expression of genes.

“The goal of our analysis was to test the effect of CALERIE intervention on biological aging,” the researchers wrote. “We measured biological aging from blood DNAm using published algorithms. These algorithms aim to capture the accumulation of molecular changes that underlie the progressive loss of system integrity that occurs with advancing chronological age.”

PhenoAge and GrimAge are two algorithms used by the researchers to provide an estimate of how much a person has aged—apart from the number of years the person has lived. DunedinPACE, which estimates the pace of aging, was also used.

The results showed the calorie-restricted diet slowed the pace of aging per the DunedinPACE measurement by 2% to 3%.

Based on previous findings, researchers posed that “the CALERIE treatment effect of 2% to 3% slower pace of aging corresponds to a reduction in mortality risk of as much as 10% to 15%, similar in magnitude to the effect of smoking cessation intervention.”

Researchers did not observe significant changes in biological age estimates measured by the PhenoAge and GrimAge algorithms.

Importantly, researchers said the long-term effects of the intervention are unknown.

“Follow up in the CALERIE trial did not extend beyond the intervention,” they wrote. “It is therefore unclear if the changes in DunedinPACE observed during the 2-year intervention will translate into reduced morbidity and mortality over the long term.”

A follow up of trial participants is now ongoing to determine whether the benefits to aging will continue.

Rachel Adams joined Informa’s Health & Nutrition Network in 2013. Her career in the natural products industry started with a food and beverage focus before transitioning into her role as managing editor of Natural Products INSIDER, where she covered the dietary supplement industry. Adams left Informa Markets in 2019.