The climate you live could influence the speed at which you are aging at the cellular level, according to a new study.
Compared to people living in cooler areas, those who live in regions with extreme more frequent heat had an accelerated biological age – the age of cells rather than the amount of time since birth, researchers have reported Scientific advances.
As climate change is progressing, more people in the world Live very hot temperatures. In the United States only, the average season of heat waves was 46 more days in 50 of the largest cities in the country than it was in the 1960s.
Heat waves can have devastating health consequences, especially for the elderly. Stifling conditions may increase the risk of hospitalizations, cardiovascular diseaseRenal and mortality dysfunction, co-author of the study Eunyoung Choi, PhdA postdoctoral partner with Leonard Davis School of Gerontology, University of South California, said Health.
The new results offer new information on how these conditions could develop. “The effects of extreme heat may not appear immediately as a diagnosed state of health, but they could make a silent toll on our body,” said Choi. “We have sought to discover these hidden effects of heat on the body, an important precursor before turning into more serious health results.”
For their research, Choi and his colleagues relied on blood samples with 3,679 participants aged 56 or over registered in the national health and retirement study.
They examined the samples, collected at different times over six years, for epigenetic changes – a measure of the way in which external environmental factors hit the “ON” and “OFF” switch for individual genes by a process called DNA methylation. To quantify these changes, the team used epigenetic clocks, tools that consider organic age based on methylation models.
“These clocks offer one of the best tools we currently have to assess how environmental exhibitions affect organic aging,” said Choi.
Scientists then compared the changes in the biological age of people with the historical readings of the heat index of their location and the number of heat days recorded by the heat of the heat indices of the National Weather Service between 2010 and 2016. Phoenix and Tucson in the south of Arizona, Brownsville and Laredo in South Texas, and Miami and Tampa of Florida have emerged as some of the most hot.
“These locations have experienced a high number of extreme heat days, defined as days when the heat index has reached or exceeded 90 ° F,” said Choi. “Some of these regions have recorded more than 140 days of extreme heat per year, which is among the areas most exposed to the country’s heat.”
Participants living in these areas experienced up to 14 months of additional organic aging compared to those who live in regions with less than 10 days of heat per year. These links were maintained even when researchers considered factors such as physical activity, alcohol consumption and socioeconomic differences.
“Although some previous studies have suggested that exposure to heat could influence aging, they were often limited to smaller and specific populations,” said Choi. “By taking advantage of a representative sample at the national level of older American adults, our study provides broader evidence than chronic heat exposure can accelerate biological aging at the level of the population.”
As for how this could happen, Choi highlighted higher temperatures potentially triggering cellular stress and inflammation, as well as influencing DNA methylation models. This can delete or activate genes, potentially leading to systemic effects, said Choi.
These results may seem frightening if you are older and live in a warm climate, but keep in mind that the study shows only an association between accelerated biological aging and frequent episodes of extreme heat – it does not prove causality.
The authors noted that the study also has certain drawbacks. For example, the researchers had no information on the use of the air conditioning of a participant, which could have had a “attenuating” effect on residents. In addition, the “validity” of the use of epigenetic clocks through genetically and environmental populations has not been established – and researchers do not know if the epigenetic changes they have seen are even so bad. They can represent “adaptive heat responses” rather than “only unsuitable changes associated with accelerated aging”.
Also, don’t forget that “results do not mean that each person living in warmer areas has an older biological age,” added Choi. “On the contrary, on average, people in warmer regions tend to show faster signs of aging. Two people living in the same district can have very different heat exhibitions based on lifestyle and socio-economic factors. »»
Future research, such as that focusing on more subtle temperature changes, is necessary to have a more complete understanding of this urgent subject, said Barrak Alahmad, MD, MPH, PHDAn environmental health instructor at the Harvard Th Chan School of Public Health.
It doesn’t matter if accelerated organic aging is at stake, it is clear that heat waves can be dangerous for aging populations. Experts did not mention that this was going to extreme lengths like moving, but they suggested taking additional precautions when temperatures increase.
To stay safe, Tarik Benmarhnia, PhdAssociate professor at the Scripps Institution of Oceanography at the University of California in San Diego, recommends drinking a lot of water, staying inside if possible and looking for air -conditioned spaces, such as local cooling centers. “Wearing light and breathable clothing can help reduce thermal tensions,” said Choi.
But it is also up to the communities themselves to offer solutions, said Choi. “As extreme heat events become more common, we have to pass reactive emergency responses to proactive infrastructure and health planning,” she said.