"Working in Heatwaves Is Already Tough"...More Heat Exposure Leads to Faster Aging

Study Tracks 2,318 Chinese Adults Over Four Years
More Than Half Show Evidence of Accelerated Aging
Experts Recommend Tailored Strategies for Vulnerable Groups

There is evidence that repeated exposure to heatwaves accelerates biological aging in middle-aged and older adults.

A photo to help understand the article showing a farmer resting after removing weeds under the blazing sun in a field in Okpo-eup, Dalseong-gun, Daegu on the 6th. Photo by Yonhap News.

According to News-Medical and other UK medical outlets on August 10 (local time), researchers at Zhejiang University in China published a paper on this topic in the international journal "Cyborg and Bionic Systems" on July 15. This journal is a sister publication of "Science."

The research team analyzed data from 2,318 individuals aged 45 and older who participated in the China Health and Retirement Longitudinal Study (CHARLS). The participants were residents of 50 cities in China, and the study compared their biometric indicators and meteorological data at two points in time: 2011 and 2015. Over these four years, the participants' average biological age increased by 5 years, from 57.3 to 62.3. A total of 58.8% experienced "accelerated aging," meaning their biological age advanced faster than their actual age.

Biological age was calculated using the Klemera-Doubal Method (KDM), which combines eight clinical metrics: C-reactive protein (CRP), glycated hemoglobin, total cholesterol, triglycerides, blood urea nitrogen, serum creatinine, platelet count, and systolic blood pressure. Heatwave exposure was evaluated based on the number of heatwave events and days in each city over the 12 months prior to measurement, with intensity categorized by varying temperature thresholds and durations.

The association between heatwaves and aging became clearer under stricter criteria. Under the most stringent heatwave standard, each additional heatwave was associated with a 0.531-year (about 6.4 months) increase in biological age, and each additional heatwave day added 0.057 years.

The strongest heatwave, as defined by the researchers, occurred when the apparent temperature for a given area was within the top 2.5% of local meteorological data for four or more consecutive days. This approach uses local temperature distribution, not absolute temperature, as its standard.

On the 28th of last month (local time), a woman stands in front of a hose spraying mist in the heatwave in Cologne, Germany. Photo by AP Yonhap News.

There have been previous studies exploring the relationship between heatwaves and aging. In February last year, a team led by Professor Jennifer Ailshire and Dr. Choi Eunyoung at the University of Southern California published in Science Advances the results of analyzing blood samples from 3,686 Americans aged 56 and older. According to their findings, measured via epigenetic clocks, people living in warmer areas aged up to 2.48 years faster than those in cooler areas.

In August of last year, Assistant Professor Guo Cui and colleagues from the Department of Urban Planning, Faculty of Architecture at the University of Hong Kong reported in Nature Climate Change the "long-term impact of heatwaves on accelerated aging." Analyzing data from 24,922 adults in Taiwan between 2008 and 2022, the New York Times interpreted the results to mean that two years of heatwave exposure could add 8 to 12 days to one's physiological age. For people working outdoors, the increment was even greater—an additional 33 days under similar conditions. Rural residents and those living in areas with low air-conditioning usage were especially affected.

Xu Dengyong, a researcher at Zhejiang University, stated, "We need new strategies to respond to climate change and tailored approaches to protect people vulnerable to temperature changes." However, he noted to Canada's CTV News that this was an observational study, so a direct causal relationship cannot be established. Whether repeated heatwave exposure actively accelerates systemic aging, and the precise biological mechanisms involved, remain to be determined.

This content was produced with the assistance of AI translation services.