Recent scientific studies have found that long-term exposure to high temperatures accelerates human aging, and this effect can be observed through changes in DNA methylation patterns. Research indicates that people living in persistently hot regions often have a biological age higher than their chronological age, with the rate of aging comparable to the impact of smoking or alcohol consumption.

Using “epigenetic clocks,” scientists discovered that even after heat waves have passed, some epigenetic changes in human DNA persist, potentially causing long-term gene expression imbalances. These alterations are associated with chronic inflammation, cellular damage, and increased risks of cardiovascular and metabolic diseases.

A study conducted by the Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, analyzed 2,084 participants. Daily temperature and relative humidity data were collected, and environmental exposure at each participant’s residence was estimated using ordinary kriging from weather station data. Average temperature and Heat Index (HI) values over the 1–180 days prior to sampling were calculated to evaluate the effects of different exposure windows.

Aging indicators: DNA methylation clocks were used, and the difference between biological and chronological age was taken as a measure of “age acceleration.”
Statistical analysis: Multiple linear regression was applied to examine the associations between heat and HI exposure and age acceleration.

Results: Both temperature and HI exposure were significantly associated with accelerated DNA methylation age, and longer exposure periods amplified the effects.
Conclusion: Long-term exposure to high ambient temperature and Heat Index is clearly associated with biological age acceleration (DNA methylation age exceeding chronological age). Extreme heat driven by climate change is not only a short-term health threat but may also have profound effects on human aging and disease. Experts recommend that governments and communities invest in cooling strategies, such as expanding green spaces, establishing cooling centers, and improving residential cooling systems, to reduce risks for older adults and vulnerable populations.

Reference:

1.Ailshire, J. et al.Ambient outdoor heat and accelerated epigenetic aging among older adults in the U.S. Science Advances, 2025.

2. Chiu, K.-C., Hsieh, M.-S., Huang, Y.-T., & Liu, C.-Y. (2024). Exposure to ambient temperature and heat index in relation to DNA

   methylation age: A population-based study in Taiwan.