Hot to go: extreme heat can make people age faster

Warming temperatures may be taking a toll on older adults. New research has linked extreme heat exposure to a higher epigenetic age, indicating that climate change could be accelerating the aging process. Understanding how heat affects the human body can help humans better prepare as the planet's temperatures continue to warm.

Warm bodies

According to a new study published in the journal Science Advances, high temperatures and regular heat waves "could be chemically modifying people's DNA and speeding up their biological aging," said The New York Times. Even when controlled for several factors, "a person living in an area that reached 90 degrees or above for 140 days or more in a year could age up to 14 months faster than someone in an area with fewer than 10 extreme heat days a year."

The study analyzed the epigenetics, or how external factors like extreme heat can affect how genes operate, of 3,686 adults starting at an average age of 68 years. "Epigenetic age is one way we measure biological aging, which tells us how well our body is functioning at the physical, molecular and the cellular levels," lead author of the study, Eunyoung Choi, a postdoctoral associate at the University of California's Leonard Davis School of Gerontology, said to ABC News. "We know that some people seem to age faster than others, and that's because biological aging doesn't always match chronological age."

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This was evident as the data "revealed a significant correlation between neighborhoods with more days of extreme heat and individuals experiencing greater increases in biological age," said a release about the study. In one of the cases, "two people that had identical sociodemographic characteristics and similar lifestyles, just because one is living in a hotter environment, they experience additional biological aging," Choi said.

Changing conditions

This study is the first to establish a connection between epigenetic aging and exposure to heat. However, there is "not enough data to definitively conclude that heat exposure caused the acceleration in aging — only that the two appear linked," said the Times. The analyzed data "didn't contain details about individuals' lifestyles, such as whether they had access to air conditioning or spent the majority of time indoors." Also, some people "may be more resilient, while others may face greater risks due to preexisting health conditions or socioeconomic barriers," Choi said in The Conversation.

There is also room for positive epigenetic changes. "The study doesn't clarify whether they could reflect positive adaptations to heat instead of negative ones," Gregory Wellenius, an environmental epidemiologist at Boston University School of Public Health, said to the Times. It could be possible that those who live in warmer regions with regular exposure to heat may have acclimated to the weather. Despite this, extreme heat is more dangerous to human health than previously thought. Climate change is only going to increase temperatures and heat waves globally, so "developing age-appropriate solutions that allow older adults to safely remain in their communities," is more important than ever.