A new study by researchers from the USC Leonard Davis School of Gerontology has found that extreme temperatures can accelerate the ageing process in humans. Published in Science Advances, the study focuses on biological age, which reflects how well the body functions at the molecular, cellular, and system levels, as opposed to chronological age based on one’s birthdate.
Extreme Heat Linked to Accelerated Biological Ageing in Older Adults, Study Finds
The research, conducted on 3,600 US participants aged 56 and older, examined the impact of temperature on biological ageing using the heat index values from the US National Weather Service. These values categorize heat risk into three levels: “Caution” (26.6°C to 32°C), “Extreme Caution” (32°C to 39°C), and “Danger” (39°C to 51°C). The study tracked heat days at all three levels.
The findings revealed that greater exposure to extreme heat days was linked to accelerated biological ageing, even after adjusting for factors like socioeconomic status, lifestyle choices, and demographic differences. Jennifer Ailshire, the senior author and professor of gerontology, explained that participants in regions with extended heat days, such as Phoenix, Arizona, experienced up to 14 months of additional biological ageing compared to those in areas with fewer than 10 heat days per year.
Heat and Humidity Pose Greater Risks to Older Adults’ Biological Ageing, Study Shows
The study emphasizes the significant role of heat and humidity, particularly for older adults who may struggle with heat regulation due to diminished sweating ability. Ailshire highlighted that the combined effects of heat and humidity can have a more severe impact on older individuals, who lose the skin-cooling effect of sweat evaporation over time.
The researchers aim to further explore which factors make individuals more vulnerable to heat-related biological ageing and how this relates to clinical health outcomes.
