The notion that caloric restriction (CR) might extend lifespan is not a new one. In this intriguing study, Redman et al. sought to investigate the hypothesis that CR might reduce oxidative stress, and thus potentially slow the ageing process.

A total of 53 volunteers completed their 2-year programme, with the intervention group achieving an approximately 15% reduction in calorie intake (the target being a 25% reduction). The CR group achieved and maintained marked weight loss (mean 9kg per person), and were observed to have reduced levels of fasting insulin, leptin, and tri-iodothyronine and thyroxine, compared with the control group. The CR group’s nighttime core body temperature, hypothesised to be a biomarker of ageing, also fell over the 2 years. Urinary excretion of F2-isoprostane, indicative of oxidative stress, declined significantly from baseline in the CR group too.

Whilst the authors stress that their findings do not extrapolate directly to longevity, they suggest that CR improves efficiency of energy utilisation, which might be a means to extend lifespan.

Read the full article in Cell Metabolism 27 805–815.e4.