For this study data was analyzed from the Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy (CALERIE) Study, which is supported by the NIA, to examine whether moderate caloric restriction had the same health benefits observed in animal studies in humans. The participant’s goal for two years was to reduce caloric intake by 25%, but analysis found that the highest the group was able to reach was 12%. Even with falling short of the goal, this slight reduction was enough to activate most of the biological pathways that are important to healthy aging, according to the researchers.
“A 12% reduction in calorie intake is very modest,” said corresponding author and NIA Scientific Director Luigi Ferrucci, M.D., Ph.D. “This kind of small reduction in calorie intake is doable and may make a big difference in your health.”
Next using thigh muscle biopsies from the CALERIE participants collected at enrollment and at both the one and two years follow-ups, the researchers investigated which human genes were impacted during caloric restriction. Messenger RNA was isolated from the samples to determine their protein sequences and to use the information to identify which genes originated from specific mRNA. Additional analysis helped to establish which genes were upregulated and which were downregulated during the process. Using this information, the researchers were able to confirm that calorie restriction in humans affected the same gene pathways as in mice and non-human primates; such as upregulating genes responsible for energy generation and metabolism, as well as downregulating inflammatory genes leading to reduced inflammation.
“Since inflammation and aging are strongly coupled, calorie restriction represents a powerful approach to preventing the pro-inflammatory state that is developed by many older people,” said Ferrucci.
