The study conducted by researchers at Penn State University analyzed data from the CALERIE trial, which investigated whether caloric restriction could slow the process of cell aging by affecting the length of telomeres. Telomeres are sections at the end of chromosomes that shorten as cells age. The study found that initially, caloric restriction accelerated telomere shortening, but after a year, it began to slow the process. At the end of 2 years, both the calorie restricted and control group had lost similar telomere length, suggesting a possible plateau effect.
The CALERIE trial recruited 220 participants aged between 21 and 50 who had a body mass index (BMI) of between 22 and 28 kg/m2. Two-thirds of the participants committed to 25% calorie restriction for 24 months, with the rest acting as controls. All participants were advised to undertake moderate exercise regularly. Throughout the study, the researchers monitored weight changes, and participants on caloric restriction lost weight initially, which stabilized over the next 12 months. Telomere length was measured at the start of the study, at 12 months, and at 24 months, showing a faster decrease initially in the caloric restriction group.
Previous studies have shown that caloric restriction may have health benefits, including reductions in cholesterol, blood pressure, and inflammatory markers. However, negative effects on bone density and muscle mass have also been observed. The researchers from Penn State found that the stress of weight loss accompanying caloric restriction might have accelerated telomere attrition initially, but it was mitigated as new homeostatic norms were established. The study underscores the complexity of how caloric restriction affects telomere loss and the need for longer-term studies to draw firm conclusions.
The findings from this study suggest that caloric restriction may have a nuanced effect on telomere length and aging in people, with initial acceleration followed by a slower rate of telomere shortening after weight stabilization. The researchers plan to follow up with participants after 10 years to observe further changes in telomere length. Chief longevity officer Sebnem Unluisler emphasizes the importance of long-term studies to understand the aging process fully and to create personalized approaches for healthy aging and disease prevention. This study adds valuable insights into how diet affects cellular aging and the complex relationship between genes, environment, and lifestyle choices in shaping health outcomes.