New study makes stunning revelation about unexpected factor causing people to age faster: 'Similar to the effect of smoking and drinking'

If rising global temperatures have you feeling worn down, you aren't alone. A new study published in Science Advances and reported on by NPR found that extreme heat can speed up biological aging in a way that researchers say is "similar to the effect of smoking and drinking." That's the warning from Eunyoung Choi, a gerontologist at the University of Southern California and the lead author of the study.

What happened?

Researchers analyzed blood samples from more than 3,600 U.S. adults over age 56 and compared their genetic markers to past weather data for their home regions. They looked for signs of "epigenetic aging," a process that changes how our genes behave and is linked to an earlier onset of health conditions such as dementia, cardiovascular disease, and diabetes.

They found that people who lived in areas with prolonged heat — such as Phoenix, where the heat index topped 90 degrees for more than half the year — appeared biologically 14 months older than people living in cooler regions. And that was after considering other factors such as income, education, exercise, and smoking, showing that heat exposure alone has an effect on how fast our bodies age.

Why does extreme heat matter?

Scientists have known that heat can negatively affect our health in many ways, from heart issues to increased hospital visits and deaths during heat waves. But in the long term, premature aging also strains families and health systems.

"It's just a tremendous strain … that increases your medication budget [and] really can have tremendous impacts," said gerontologist Deborah Carr of Boston University, who was not involved in the study.

As global temperatures rise, fueled by our use of dirty energy sources such as oil and gas, extreme heat days are expected to increase across the U.S. by 20 to 30 days annually by the middle of the century. And that's happening at the same time America's population is aging, a concerning overlap since older adults are more vulnerable to heat-related complications.

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Prolonged exposure to heat makes "you sort of accelerate your way towards an old heart, and an old vulnerable heart," Tom Clanton, a physiologist and heat expert at the University of Florida's College of Health and Human Performance, explained.

What is being done about rising temperatures?

Researchers say this helps explain the connection between heat and illness. It also points to the need for personalized assessments of heat exposure, especially in homes and communities without reliable cooling.

The next step for researchers is to better understand how individual environments — such as overheated homes or neighborhoods with less green space — contribute to heat exposure and health risks. That information could help shape future solutions, from city planning to home cooling upgrades.

To protect your household from extreme heat while saving money on electric bills, consider climate-smart upgrades such as installing a heat pump (which also cools your space) or taking steps to weatherize your home.