A new study in press in the journal Nature Aging has shown that caloric restriction can slow the pace of aging in healthy adults.
The Phase 2 randomized controlled trial, funded by the U.S. National Institute on Aging, included 220 non-obese, healthy adults from the United States. Participants were randomized to either a 25% calorie restriction diet (25% below the participants’ estimated energy requirements) or a normal diet (ad libitum) for two years. To measure the pace of aging in participants, a DNA methylation analysis was performed on blood samples from the participants at baseline, 12 months, and 24 months. This analysis measures tags on DNA sequences that regulate gene expression, which are known to change as people age. Measuring rates of survival and occurrences of age-related disease are not practical due to time constraints, so biomarkers associated with aging progress provide a reasonable substitute.
According to the DunedinPACE algorithm, which computes the approximate pace of aging from the epigenome, the caloric restriction group saw a 2–3% reduction in the pace of aging compared to the control group. In other studies, this would correspond to a 10–15% reduction in mortality risk, which is comparable to the benefits of quitting smoking.
The study authors noted that while the results are promising, caloric restriction is difficult and may not be for everyone. Future trials might include more appealing options, such as time-restricted eating, that may have similar effects. The beneficial effects of caloric restriction have been well-established in model organisms, including the extension of healthy lifespans and the delay of chronic diseases. Aging is strongly associated with an increased risk for cardiovascular disease, and interventions such as caloric restriction have the potential to expand heart health and delay chronic cardiovascular issues.
Sources: Medrxiv, Science Daily