Severe fever can accelerate biological aging in elderly individuals

Extreme fever appears to speed up biological aging in older adults, suggesting that it may increase the risk of age-related diseases.

“This is one of the first large-scale studies linking long-term heat exposure to biological aging in humans,” he says. Eun Young Choi At the University of Southern California. “Elderly people who live in areas with biologically extreme heat in cooler areas.”

Choi and her colleagues analyzed genetic data extracted from blood samples collected by other researchers from 3,600 people in the US in 2006-7. At the time, they were all over 56 years old.

They estimated the biological age of each participant using three so-called epigenetic clocks, including seeing patterns of chemical tags called methyl groups on DNA. These patterns change as we age, and such changes are associated with age-related diseases.

The researchers also looked at daily temperature measurements taken within a few kilometres of where participants lived for six years before blood samples were collected.

They found that every 200 days of six years when participants were exposed to daily maximum temperatures of at least 32.2°C (90°), biological age was on average up to 3.5 months old, and on average up to 3.5 months of age than those in cooler areas. That number depends on which watch was used.

“This refers to heat exposure increasing the rate of biological aging,” he says. Austin Argencheri At Harvard University, where he was not involved in the research.

Previous studies on the Taiwanese and German people have also found a link between extreme heat exposure and biological aging.

However, epigenetic watches do not fully capture the aging process or the risk of people's illnesses, says Argentieri. “More jobs that can link both extreme heat exposure, biological aging from these watches, age-related diseases, mortality and the effects on life expectancy itself will help us drive home what we need to take away from now on.”

Furthermore, the study did not consider access to air conditioners or the duration of time participants spent outdoors, so individual exposure changes to heat exposure, says Argentieri. The team controlled for other factors such as age, gender, race, wealth, ethnicity, smoking status, alcohol consumption, obesity, and physical activity.

Furthermore, research should investigate whether results will be translated to younger people or to people living in different countries where people may have different approaches to keeping people cool, says Argentieri.

Identifying the people who are at the lowest risk of aging fastest due to extreme heat could help policymakers develop and deploy measures to protect them, he says.