New first-of-its-kind research from the US shows adults living in warmer areas are more physically affected by ageing than those in cooler ones.
The research, which was published on Wednesday in the online journal Science Advances, included the analysis of over 3,600 adults aged 56 and older in America and found those living in neighbourhoods exposed to extreme heat – classified as 90 degrees or above – showed more accelerate aging at a molecular level compared to cooler places.
To conduct the research, experts used tools called epigenetic clocks – a biochemical test that estimates a person’s biological age by measuring changes in DNA methylation. They looked at their age estimates alongside six years of daily climate data, comparing them across geographies.
This is the first population-level analysis to establish a correlation between heat exposure and epigenetic ageing in humans.
Jennifer Ailshire, senior author of the study and professor of gerontology and sociology at the USC Leonard David School, said: ‘Participants living in areas where heat days, as defined as Extreme Caution or higher levels (greater than 90 degrees Fahrenheit), occur half the year, such as Phoenix, Arizona, experienced up to 14 months of additional biological aging compared to those living in areas with fewer than 10 heat days per year.
‘Even after controlling for several factors, we found this association. Just because you live in an area with more heat days, you’re aging faster biologically.’
‘It’s really about the combination of heat and humidity, particularly for older adults, because older adults don’t sweat the same way. We start to lose our ability to have the skin-cooling effect that comes from that evaporation of sweat,’ she continued. ‘If you’re in a high humidity place, you don’t get as much of that cooling effect. You have to look at your area’s temperature and your humidity to really understand what your risk might be.’
While the progress is looking positive, the research team have acknowledged there is still work to be done. In the meantime, the study results could prompt policymakers and architects to keep age friendly measures in mind as they update cities’ infrastructure.
‘If everywhere is getting warmer and the population is aging, and these people are vulnerable, then we need to get really a lot smarter about these mitigation strategies,’ Ailshire added.
The research can be accessed in full here.
Photo by Tomek Baginski via UnSplash
In related news:
Hospital admissions for eating disorders are skyrocketing, NHS figures show