A new study conducted by researchers at Penn State College of Health and Human Development explored how caloric restriction affects telomeres, which are protective caps at the ends of chromosomes. Previous research has shown that caloric restriction can lead to longer life in animals. Telomeres naturally shorten as cells replicate, and shorter telomeres can lead to cell damage and dysfunction. By examining the effects of caloric restriction on telomere length in humans, the researchers hoped to uncover ways in which this dietary intervention could slow down aging.
The study analyzed data from the CALERIE study, the first randomized clinical trial of calorie restriction in humans. By testing the telomere length of study participants at the beginning, one year in, and at the end of the two-year study, the researchers found that caloric restriction initially led to more rapid telomere loss, but this trend reversed after participants’ weight stabilized. At the end of the study, both the caloric restriction group and the control group had similar telomere lengths, suggesting that caloric restriction did not have a significant impact on telomere length in the short term.
Despite the unexpected findings, the researchers remain optimistic about the potential health benefits of caloric restriction in humans. Previous research on the CALERIE data has shown that caloric restriction can help reduce harmful cholesterol levels and lower blood pressure. While the two-year timeline was not sufficient to demonstrate benefits on telomere length, follow-up data collection scheduled for a 10-year follow-up may provide more insights into the long-term effects of caloric restriction on aging. The researchers are eager to analyze these data and further explore the complexities of how caloric restriction impacts telomere loss.
Three of Dr. Idan Shalev’s trainees, including Waylon Hastings, who led the study, have played significant roles in this research. For Hastings, the opportunity to lead this study has been critical to his career development, as it has led him towards a new position as an assistant professor in the Department of Nutrition at Texas A&M University. The collaboration with researchers from other institutions, including Columbia University, Tufts University, Duke University, University of British Columbia, Pennington Biomedical Research Center, and Arizona State University, helped to bring diverse expertise to the study.
Overall, the research sheds light on the complex relationship between caloric restriction and telomere length, raising important questions about the potential long-term effects of this dietary intervention on aging. Despite the initial findings of more rapid telomere loss in participants on caloric restriction, followed by a slower loss after weight stabilization, the researchers remain hopeful that further exploration of the data will reveal additional health benefits of caloric restriction in humans. The National Institute on Aging funded this research, highlighting the importance of understanding the impact of diet on aging for promoting healthy aging strategies in the future.
