A new study suggests that heat waves may contribute to speeding up biological aging, adding to the growing concerns about climate change’s impacts. The results, published in the journal Cyborg and Bionic Systems in July, indicated that exposure to periods of extremely hot weather was “significantly associated” with the deterioration of body functions, or “longer-term physiological damage,” in middle-aged and older adults. Researchers used data from the China Health and Retirement Longitudinal Study, which involved more than 2,300 middle-aged and older adults who were at least 45 years old, according to a press release posted last week. The study found an increase of five years in the biological age of participants over a four-year period. The average biological age of participants rose from 57.3 years in 2011 to 62.3 years in 2015. Researchers noted that 58.8 per cent of them showed “biological age acceleration” during follow-ups. Jem Cheng, a human thermoregulatory physiologist who was not involved with the study, told CTVNews.ca in a video interview Tuesday that biological aging represents “the health and function of our cells, our body systems, and our organ systems,” while chronological aging is the number of years that an individual has been alive. She said it was “concerning” to see evidence suggesting that extreme heat doesn’t only have an immediate impact, such as with heat-related illnesses, hospitalizations and even deaths. “This is perhaps some of the first evidence … that suggests that there are long-lasting effects of extreme heat exposure on people,” said Cheng, an assistant professor at the University of British Columbia’s Okanagan campus. “So really, the significance of this study is showing … heat wave exposure is causing aging within our body’s organ systems and our physiological systems, and that aging process may be accelerated, even after a heat wave event has occurred,” she added. Study looks at impact of climate change: researchers Dengyong Xu, one of the authors of the study and a researcher at China’s Zhejiang University, said investigating the link between heat wave exposure and biological aging could help in developing strategies to address climate change and identifying individuals who may be most “vulnerable” to the effects of the long-term changes in weather patterns and temperatures. But researchers said the study is “observational and cannot establish direct causality.” “However, whether recurrent heatwave exposure accelerates systemic biological aging, and what biological mechanisms may underlie this association, remain unclear,” Xu said in the press release. Xu said that “heat stress” may disrupt metabolism, organ functions and inflammatory responses. The effects of heat waves were stronger in those with “higher (body mass index), urban residents, and people living in southern or subtropical regions, indicating that metabolic status and living environment jointly shape vulnerability to heat exposure,” the press release stated.
