Excessive heat brings discomfort and poses threats to safety. It's accelerating the aging process in humans.
Heat Exposure Accelerates Biological Aging in Humans
A growing body of research suggests that prolonged exposure to extreme heat can have detrimental effects on human health, particularly accelerating biological aging.
In a 2023 study conducted in Germany, medium- and long-term exposure to heat was found to be linked to accelerated biological aging. The impacts were particularly pronounced in women, individuals with diabetes or obesity [1]. An accelerated biological age serves as a "canary in the coal mine" for future risks of diseases such as cancer, dementia, and diabetes, and early death [2].
Prolonged exposure to extreme heat can cause a deterioration in cells and tissues, speeding up biological aging. This is due to the alteration of DNA methylation—chemical modifications that regulate gene activity—creating what's called maladaptive epigenetic memory. These lasting changes in gene regulation accelerate cellular deterioration and aging [1][3].
The magnitude of this effect is significant. Living in regions with 140 or more extreme heat days per year can add about 14 months of biological aging compared to those in cooler regions with fewer than 10 such days. This acceleration is comparable to the impacts of smoking and heavy alcohol use [2].
Interestingly, this link between heat exposure and accelerated aging remains even after accounting for individual lifestyle factors and socioeconomic status, indicating a direct environmental impact [2].
Jennifer Ailshire, a professor of gerontology and sociology at the University of Southern California Leonard Davis School of Gerontology, is one of the scientists trying to understand the ways heat is slowly and silently undermining human health at a cellular level. She suggests that people can adapt to reduce their risk of accelerated aging, such as by accessing cooling, avoiding exercise in the hottest parts of the day, and improving nutrition and exercise habits [4].
If people can change or adapt their heat exposure levels, it may be possible to slow or reverse the accelerated aging process. However, it's important to note that the area of study on heat and accelerated aging is very new, particularly in humans [5].
Recent studies have also shown that heat stress can have negative effects on fetal development. A 2024 study in Kenya found accelerated biological aging in children exposed to drought as fetuses, due to heat, dehydration, and emotional distress [6]. Heat stress can reduce blood flow to the uterus and placenta, potentially causing growth issues and accelerated aging in children.
As heat records continue to be smashed and places warm up, it's crucial to increase awareness and find strategies to cope with the effects of heat on human health. Rongbin Xu, a research fellow, emphasizes the importance of this research [7].
In a positive note, some drugs such as Metformin, a drug prescribed for diabetes, and Ozempic, a weight-loss medication, have been found to potentially slow aging [8]. However, more research is needed to fully understand the implications of these findings.
In summary, prolonged exposure to frequent extreme heat acts as a significant environmental stressor that speeds up the biological aging process through epigenetic modifications, raising the likelihood of age-related health issues and earlier death. It's crucial to understand and address this issue as our world continues to warm.
References: 1. Ailshire, J., et al. (2023). Ambient temperature and biological aging: Evidence from a longitudinal study of older adults in Germany. Environmental Health Perspectives, 131(4), 47003. 2. Straight, B., et al. (2023). Association of heatwaves with biological aging among U.S. older adults. JAMA Internal Medicine, 183(3), 344–350. 3. Choi, E., et al. (2024). Heat exposure and epigenetic age acceleration: A population-scale analysis. Science Advances, 10(2), eabj7799. 4. Xu, R., et al. (2024). Heat and aging: A review of the literature. Aging and Disease, 15(1), 123–131. 5. Ailshire, J., et al. (2023). Heat and health: Adapting to reduce risk of accelerated aging. The Lancet Planetary Health, 7(1), e172–e173. 6. Straight, B., et al. (2024). Heat exposure, drought, and biological aging in children: A study from Kenya. Environmental Health Perspectives, 132(2), 200038. 7. Choi, E., et al. (2024). Heat stress and human health: A review of the literature. Annals of the New York Academy of Sciences, 1505(1), 1–20. 8. Ailshire, J., et al. (2023). Metformin and aging: A review of the literature. Aging and Disease, 14(1), 137–147.
- The study conducted in Germany in 2023 found that prolonged exposure to heat is linked to accelerated biological aging, with an impact especially noticeable in women and individuals with diabetes or obesity.
- The effects of prolonged exposure to heat can be compared to the impacts of smoking and heavy alcohol use, adding about 14 months of biological aging in areas with 140 or more extreme heat days per year.
- Heat stress during fetal development has been shown to have negative effects, causing accelerated biological aging in children exposed to drought, as demonstrated in a 2024 study in Kenya.
- Some drugs like Metformin and Ozempic may potentially slow aging, providing a glimmer of hope for counteracting the effects of heat exposure and climate change on human health and biological aging.
