Animal studies have shown that restricting calories can prolong life, and there is some evidence to suggest a similar effect in humans. Experts are still unsure of the exact mechanisms behind this phenomenon. Telomeres, which are sections at the end of chromosomes that shorten with cell aging, were the focus of a recent study investigating whether caloric restriction might slow down this process. It was found that people on restricted calories initially lost more telomere length, but the shortening then began to slow. The researchers plan to follow up with participants after 10 years to see if prolonged caloric restriction further slows telomere shortening.
Research has shown that diet and exercise can impact health as well as the speed and progression of aging. Primary aging is a natural process that everyone experiences, while secondary aging is an acceleration of aging due to factors such as excess food intake, lack of exercise, and disease. Caloric restriction has been found to slow this secondary aging process, reduce disease, and prolong life in animal studies. However, the exact reasons why caloric restriction may delay aging are still unclear.
As cells age, telomeres shorten until the cell eventually dies. Cell death is a feature of aging, so delaying this process by reducing the rate at which telomeres shorten could potentially delay aging as well. An earlier study in mice showed that caloric restriction slowed the shortening of telomeres and prolonged lifespan. Researchers from Penn State University analyzed data from the CALERIE trial to see if a similar effect could be observed in humans. They found that while caloric restriction initially accelerated telomere shortening, it began to slow down after a year.
The CALERIE trial recruited 220 participants, of which 175 were included in the data analysis. Participants were healthy adults with a BMI indicating a healthy weight to overweight. Two-thirds of the participants committed to a 25% calorie restriction for 24 months, while the rest served as controls. The researchers found that while caloric restriction initially accelerated telomere shortening, the process slowed down after a year.
Over the course of the study, the average calorie restriction achieved fell short of the 25% goal, with participants achieving a mean reduction of 11.9%. Previous analyses of the data have shown some health benefits of caloric restriction, including reductions in total blood cholesterol, blood pressure, and inflammatory markers. However, it may have negative effects on bone density and muscle mass. The researchers will follow up with the cohort at 10 years to see how telomere length changes over a longer time period.
In conclusion, caloric restriction appears to have complex effects on telomere length and cellular aging. While early findings from the CALERIE trial showed an initial acceleration of telomere shortening in response to caloric restriction, this process slowed down over time. Future research will be necessary to fully understand the impact of caloric restriction on telomere dynamics and aging. The study highlights the importance of long-term studies in understanding aging-related processes and emphasizes the need for personalized approaches to healthy aging and disease prevention.
