In the first randomized controlled trial of its kind, researchers have shown that caloric restriction can slow the pace of aging in healthy adults. The CALERIE™ (Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy) intervention slowed the pace of aging as measured by participants' blood DNA methylation using the algorithm DunedinPACE (Pace of Aging, Computed from the Epigenome). The intervention demonstrated a 2%-3% slowing in the pace of aging, which in other studies translates to a 10%-15% reduction in mortality risk, an effect similar to a smoking cessation intervention.

The CALERIE™ Phase-2 trial randomized 220 healthy men and women at three sites in the US to a 25% calorie restriction or normal diet for two years. Biological aging was assessed by analyses of blood samples collected from trial participants at pre-intervention baseline and after 12- and 24-months of follow-up.

In the primary analysis, 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." The third measure was DunedinPACE, which estimates the pace of aging, or the rate of biological deterioration over time.

The study found evidence that calorie restriction slowed the pace of aging as shown in DunedinPACE. A follow-up of trial participants is now ongoing to determine if the intervention has long-term effects on healthy aging.

To download the study, published in Nature Aging, click here