Silke Mayr New research suggests that high temperatures may have a stronger effect on biological ageing than smoking or alcohol consumption. Scientists warn that extreme heat could speed up the ageing process in older adults, raising concerns as global temperatures continue to rise.
A study published in Science Advances this week reveals that seniors exposed to prolonged heat show faster biological ageing. Researchers from the University of Southern California (USC) analyzed health data from over 3,600 Americans aged 56 and older, comparing biological markers with regional temperature trends. Their findings suggest that people living in areas with frequent temperatures above 32°C age biologically faster, sometimes by more than a year.
How Heat Affects Biological Ageing
Biological age refers to the wear and tear on cells and organs, which can differ from chronological age, the number of years a person has lived. When biological age surpasses chronological age, it increases the risk of diseases and premature death.
In this study, researchers examined blood samples collected between 2010 and 2016, including those from residents in hotter states like Arizona and Texas. Using epigenetic clocks, which measure DNA changes over time, they tracked biological ageing and compared it with local heat index data, factoring in both temperature and humidity.
The results were clear: older adults living in hotter regions experienced faster-moving epigenetic clocks, meaning their bodies aged faster at a cellular level. This accelerated ageing remained significant even after adjusting for smoking, alcohol use, exercise, and socioeconomic factors.
The Role of Heat and Humidity in Health Risks
While extreme heat alone is harmful, humidity makes it even more dangerous. High humidity prevents sweat from evaporating efficiently, making it harder for the body to cool down. This increases the risk of dehydration, heat exhaustion, and heatstroke.
Jennifer Ailshire, a professor of gerontology at USC and a senior author of the study, explains why older adults are particularly vulnerable.
“As people age, their ability to regulate body temperature weakens. Older individuals sweat less, which reduces their ability to cool down,” Ailshire says. “When humidity is high, the body struggles even more to release heat, increasing stress on the heart and other organs.”
These findings align with past studies that link extreme heat to cardiovascular disease, kidney problems, and cognitive decline. Older adults, especially those with preexisting health conditions, face the highest risks.
Climate Change and Its Impact on Ageing
The study’s findings highlight the urgent need to address climate change and protect older populations from rising temperatures. According to the World Meteorological Organization (WMO), 2024 was the hottest year on record, with global temperatures about 1.6°C above pre-industrial levels. Heatwaves are also becoming more frequent and intense worldwide.
The World Health Organization (WHO) estimates that extreme heat causes over 175,000 deaths annually in Europe alone. Without intervention, climate change could contribute to an estimated 2.3 million additional European deaths by 2099.
This latest study suggests that the long-term effects of heat on ageing may be even more severe than previously thought. If global temperatures continue to rise and life expectancy increases, the risks to ageing populations will grow.
The Need for Better Heat Mitigation Strategies
To reduce the dangers of heat exposure, experts emphasize the importance of urban planning and infrastructure changes. Cities can take several steps to help older residents cope with rising temperatures, including:
- Expanding green spaces and increasing tree coverage to provide natural cooling.
- Improving access to air-conditioned public spaces for seniors.
- Designing buildings with heat-resistant materials and better ventilation.
- Implementing early warning systems for extreme heat events.
Ailshire stresses the need for proactive measures. “If we don’t address this issue, we will see more heat-related illnesses and deaths among older adults in the coming decades,” she warns.
Conclusion
The study presents a strong case for treating extreme heat as a serious health risk, particularly for older adults. As temperatures rise due to climate change, the impact on biological ageing could become even more pronounced. Addressing these challenges will require coordinated efforts from governments, scientists, and urban planners.
For more insights on climate research and its impact on public health, visit Financial Mirror.