When it comes to our health, the microscopic telomeres, those tiny caps at the end of chromosomes, hold a surprisingly significant role. Think of them as the protective plastic tips on your shoelaces that prevent fraying—except, in this case, they safeguard your DNA from deteriorating over time.
Since the late 20th century, scientists have observed that telomeres naturally shorten as we age. This decline isn’t straightforward; it accelerates early in life before tapering off in middle age. However, recent research has uncovered a link between chronic inflammation—often a consequence of obesity—and accelerated telomere shortening, suggesting a faster biological ageing process. Interestingly, weight loss appears to counteract this effect by slowing down the rate of telomere decline.
Enter the CALERIE 2 study, which sought to explore another facet: the impact of calorie restriction (CR) on telomere length.
Diving into CALERIE 2
To understand the effects of CR, researchers recruited 175 participants who completed the two-year experiment. These individuals, with an average BMI of 25.2 at the start, were not obese but volunteered to reduce their calorie intake by 25% for the first year, followed by a year of weight maintenance.
During this rigorous study, about two-thirds of the participants adhered to the CR regimen, while the remainder continued with their usual diet.
What Did the Study Reveal?
The findings were somewhat surprising and contradictory. Initially, those who cut the most calories experienced the greatest shortening of telomere length over the first 12 months—a result contrary to expectations. However, during the subsequent maintenance phase, both the CR group overall and those who had initially cut more calories showed less telomere shortening compared to the control group.
These results were validated through multiple measurement techniques, including assessments of DNA damage and direct telomere length measurements. Despite the initial accelerated decline observed in the CR group, the overall telomere reduction after 24 months was comparable between the CR and control groups, albeit achieved at a different pace.
Key Insights
- Understanding the Stress of Calorie Restriction: Cutting calories isn’t just about shedding pounds; it’s a stressor that impacts various bodily functions beyond fat stores. Muscles, bones, organs, hormones, and the immune system all feel the effects. It’s logical that telomeres, tasked with protecting DNA integrity, might react by shortening initially under such conditions. However, stabilisation during the maintenance phase suggests the body’s adaptability to a reduced energy supply.
- Navigating the Uncertainty: While CR has shown promising longevity benefits in laboratory animals, its application to human health remains uncertain. Unlike controlled experiments with lab animals, human life is unpredictable, exposed daily to environmental factors and genetic predispositions. For many, the challenge lies not in extreme calorie cutting but in maintaining a balanced diet that sustains current weight and activity levels.
Moving Forward
In the end, the best approach might be to strive for moderation and mindfulness in eating habits while acknowledging that telomere health, like life itself, can often surprise us. As we continue to unravel the complexities of ageing and nutrition, one thing remains clear: nurturing our bodies with balanced, nutritious food and a healthy lifestyle is key to supporting overall well-being. For tailored guidance on how to achieve this, schedule a free consultation with a health coach today.
References:
Telomeres, aging, and calorie restriction. Precision Nutrition.
Ye, Qiaofeng, Abner T. Apsley, Laura Etzel, Waylon J. Hastings, John T. Kozlosky, Cade Walker, Sarah E. Wolf, and Idan Shalev. 2023. “Telomere Length and Chronological Age across the Human Lifespan: A Systematic Review and Meta-Analysis of 414 Study Samples Including 743,019 Individuals.” Ageing Research Reviews 90 (September): 102031.
Welendorf, Caroline, Carolina Ferreira Nicoletti, Marcela Augusta de Souza Pinhel, Natália Yumi Noronha, Bruna Morais Faleiros de Paula, and Carla Barbosa Nonino. 2019. “Obesity, Weight Loss, and Influence on Telomere Length: New Insights for Personalized Nutrition.” Nutrition 66 (October): 115–21.
Hastings, Waylon J., Qiaofeng Ye, Sarah E. Wolf, Calen P. Ryan, Sai Krupa Das, Kim M. Huffman, Michael S. Kobor, et al. 2024. “Effect of Long-Term Caloric Restriction on Telomere Length in Healthy Adults: CALERIETM 2 Trial Analysis.” Aging Cell, March, e14149.
Rochon, James, Connie W. Bales, Eric Ravussin, Leanne M. Redman, John O. Holloszy, Susan B. Racette, Susan B. Roberts, et al. 2011. “Design and Conduct of the CALERIE Study: Comprehensive Assessment of the Long-Term Effects of Reducing Intake of Energy.” The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences 66 (1): 97–108.
Das, Sai Krupa, Susan B. Roberts, Manjushri V. Bhapkar, Dennis T. Villareal, Luigi Fontana, Corby K. Martin, Susan B. Racette, et al. 2017. “Body-Composition Changes in the Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy (CALERIE)-2 Study: A 2-Y Randomized Controlled Trial of Calorie Restriction in Nonobese Humans.” The American Journal of Clinical Nutrition 105 (4): 913–27.
