Ongoing stress is bad for your emotional and physical health. It can promote disease, reduce the length of telomeres -- a biomarker of biological aging -- and reduce the number of years you’ll live. That much is well established.
But there's another, more subtle form of psychological stress that has a powerful influence on health and telomere length.
It has to do with the glue that binds communities together. It concerns how well neighbors are willing to help each other, whether they generally get along and can be trusted, and whether people in the neighborhood share the same values.
When considered as a whole, scientists call these features social cohesion. This, together with crime, safety, and neighborhood quality can have a major impact on how long you live.
Longer Telomeres in Better Neighborhoods
The first study to test the link between neighborhood conditions and telomere length in US adults was carried out in 2014.
Researchers used data from 978 adults aged 45 - 84 living in six regions of the United States.
They found social environments affect telomere length. In areas with low social cohesion -- as well as those rated lower for noise, litter, safety and attractiveness -- participants in the study showed greater cellular aging compared to those who lived in the most trusting and safe communities.
The following year, 239 mixed race adults living in three neighborhoods of Detroit had their blood drawn and were questioned about their communities. Those who wanted to move out of the area, but didn't have the finances or opportunity to do so, had shorter telomeres.
Where You Live May Make You Old
A study of 2,902 individuals aged 18 - 65 living in the Netherlands was also published in 2015.
Compared to those who described their neighborhood quality as good, telomere length of residents who rated it as moderate were on average 69 base pairs shorter, and those who rated their neighborhood as poor, 174 base pair shorter. In terms of age, this translates to a reduced lifespan of around 8½ and 12 years respectively.
Since many factors influence length of telomeres, the researchers, in producing their findings, took a large number of demographic, socioeconomic, community, health and lifestyle characteristics into account.
But even adjusting for these, a clear link between cellular aging and neighborhood quality was established. The authors called their study: Where You Live May Make You Old.
City Versus Country Dwellers
Is it all a matter of well-off people who live in nice neighborhoods enjoying longer life? Not necessarily.
Although income and social class would be expected to influence social cohesion, the health of a neighborhood goes well beyond this. Poor districts can also display a strong sense of community.
So how does social cohesion penetrate deep into our cells to affect the length of telomeres? There are several potential causes related to vigilance and the ability to keep good health habits.
German researchers took brain scans of participants engaged in stressful mental math tests while receiving instant feedback on their answers. They found city dwellers had a larger stress response than country folks in the amygdala, a tiny area of the brain associated with the reaction of fear.
This occurred because there is less stability, increased danger and greater stress in city living. People are more vigilant and ready to mount a big stress response to any perceived threat.
That's one reason people living in less socially cohesive conditions have shorter telomeres. The other is that in such areas people may not sleep as soundly or be less inclined to exercise outdoors. Less sleep and exercise means shorter telomeres.
So if you're not happy where you live, it's worth thinking about moving to a safer area with high neighborhood quality and social cohesion.
Once you've recovered from the stress of moving to a different home, there's a good chance it will help maintain the length of your telomeres and extend your life.
