Prolonged obesity in early life linked to accelerated biological ageing, study finds
Key Takeaways:
- Individuals with persistent obesity from early childhood or adolescence show signs of biological ageing years ahead of their chronological age.
- Researchers observed increases of over 4.5 years in biological age and up to 48% acceleration in some individuals, alongside molecular markers of physiological decline.
- Findings challenge the long-standing belief that calorie restriction is the key modulator of ageing, suggesting instead that obesity itself may drive premature ageing.
Introduction: Obesity and Ageing – Rethinking the Relationship
New research from the Santiago Longitudinal Study has found that individuals with long-term obesity exhibit signs of accelerated biological ageing as early as their late twenties. The findings, published in JAMA Network Open, provide compelling evidence that sustained obesity from childhood or adolescence may hasten physiological decline at a molecular level – in some cases by nearly five years compared to chronological age.
The results pose a significant challenge to traditional models of ageing, which have focused heavily on the benefits of caloric restriction. Instead, the authors argue that excess calorie intake and the associated hormonal and metabolic changes of obesity may directly contribute to the ageing process.
Study Overview: A Longitudinal View of Lifespan Health
The research team, led by Dr Paulina Correa-Burrows of the Universidad de Chile, drew on data from over 1,000 participants in the Santiago Longitudinal Study, a project tracking individuals from birth through to young adulthood. For this analysis, the focus was narrowed to 205 participants with complete data sets:
- 89 individuals with a normal body mass index (BMI)
- 43 individuals with obesity beginning in adolescence
- 73 individuals with obesity starting in early childhood
Participants were followed until they reached the ages of 28 to 31 years, at which point a range of biological ageing markers were assessed.
Biological Ageing Measured by Epigenetic Clocks
To estimate biological age, researchers used multiple advanced methods, including:
- DNA methylation-based epigenetic clocks
- Estimation of leukocyte telomere length
- Circulating biomarkers such as cytokines, adipokines, myokines, and growth factors
The findings were stark. In participants with long-term obesity, epigenetic age exceeded chronological age by:
- 2.23 to 4.68 years, depending on the method used
- 15.2% to 16.4% increase on average
- Up to 48% in some individuals
These results suggest that long-term obesity may induce molecular signatures typically associated with ageing, including telomere shortening, mitochondrial stress, chronic inflammation, and disrupted intercellular signalling.
Rethinking the Role of Calories in Ageing
In an editorial accompanying the study, Dr Antonello Lorenzini reflects on the broader implications of these findings. Historically, the biology of ageing has centred on the notion that caloric restriction slows ageing. However, Dr Lorenzini proposes a paradigm shift:
“The average level of biological age is clearly elevated in the two groups experiencing lasting obesity,” he wrote.
“This elevation strongly suggests that it is time to doubt the classical interpretation that has dominated the field of biology of aging for a long time: caloric restriction slows down the aging process.”
He suggests that the presence of excess calories, the hormonal imbalance of obesity, or both, may serve as active drivers of ageing.
Implications for Public Health and Ageing Research
Dr Lorenzini also highlights the public health implications of these findings, particularly given the scale of the global obesity epidemic:
“A new awareness of the effect of obesity in accelerating the aging process represents an additional element for educational campaigns that aim to address the globesity epidemic,” he wrote.
Rather than advocating for restrictive diets or prolonged hunger, Dr Lorenzini suggests a more balanced approach to healthy ageing:
“The recipe for a long and healthy life, therefore, does not seem to require experiencing hunger, but rather simply avoiding mental and physical stress, getting an appropriate amount of physical activity, and modifying the diet to increase foods that prevent obesity while reducing those that promote it.”
Conclusion
This study adds to a growing body of evidence linking long-term obesity with premature biological ageing. While more research is needed to establish causal mechanisms and explore potential interventions, the findings underscore the importance of early-life obesity prevention and raise critical questions about how we understand and modulate the ageing process.
