We are losing these ‘old friends’

Maria Isabel Garcia
There is a deep, biological reason why we gravitate toward rural areas when we need a break from our frenzied city lives

I have always felt inferior in many ways to those who have hometowns.

In fact, I have gravitated toward friends who have provinces more than those who do not identify with any. That’s probably because I did not have a hometown. The town that my father considered his ancestral landscape urbanized quite quickly. My second reason is that people who grew up in hometowns just seem to have much more interesting stories about their childhood, because it is strongly tied to a sense of place. I find their kind of authenticity much more grounded and refreshing than that of city-bred ones like me. Another reason is that they seem to consider their hometowns a place to return to when their “second homes” fail them.

Recently, though, a new study has just given me another reason to envy them. And this time, it’s scientific.

The study examined the immunity reactions of two groups of people: those who were born and raised (until about 15 years old) in rural areas with animals, and those who were born and raised in urban areas (until also about 15 years old) with no animals. The researchers had good reasons to be interested in this, as it is known in science that we humans have evolved being exposed to a wide range of microbes, and that our immune system has grown to be robust because of our adaptation to this wide range. Scientists refer to these microbes as “old friends.” This range in microbes depends on the environment, and it’s where rural and urban places greatly differ, with rural places harboring a lot more.

But with the rapid loss of rural areas, we are losing these “old friends.” According to previous studies the researchers cited, this could account for the significant difference in the prevalence of mental disorders among those who were born and raised in urban areas versus those in rural areas.

Rural environments harbor much more biological diversity than urban ones because the kinds of living spaces in rural areas and the variety of other life forms they harbor are home to more kinds of microbes. Urban areas, with their large-scale sanitation (including water treatment), infrastructure, and pollution limit the kinds of microbes that they harbor. The support systems in urban areas – with their increased caesarian section birth rates over natural delivery, replacements for breast milk, and the excessive use of antibiotics – also radically define the limited range of microbes.

The study induced a standard psychosocial test for the urban and rural groups, and afterwards, examined markers of their immune system at several intervals. These included blood and saliva samples, as well as taking their blood pressure and heart rate.

In the blood, they looked for markers of inflammation, which is a very telling mark of how our immune system is reacting. The reaction of our immune system is to inflame our “insides” when it senses that it is being attacked. That’s natural, but an overactive immune system triggers frequent and more sustained inflammation, which is strongly linked with many physical and mental disorders. In saliva, they looked for a protein that mirrors the state of our sympathetic nervous system – another reflection of how our body is reacting to the stress we experience.

The scientists found that those who were born and bred in rural areas with animals had a much more robust immune system. This meant that they did not have an overactive immune system. The ones who were born and raised in urban areas without animals had markers that reflected overreactive immune systems.

You are probably wondering at what age losing our old, biological “friends” will have an effect. The mean age of those tested was 25. This means the effects show up right away, and when we are supposed be at the prime of our lives.

There is a deep, biological reason why we gravitate toward rural areas when we need a break from our frenzied city lives, even if we were not born and bred in rural areas. Our bodies harbor immune systems that have “natural hometowns” in rural areas with animals. Those who were lucky enough to have been born and bred there generally seem to have the natural advantage, because they have not really “lost their old friends.”

The United Nations predicts that based on trends, the world will be 70% urbanized by 2050. In some ways, it will be progress, but in others, like for our health which is dependent on beneficial microbes, it will not be good news. By gaining a city after city, we may, in a big sense, lose our bodies and souls. – Rappler.com

Maria Isabel Garcia is a science writer. She has written two books, “Science Solitaire” and “Twenty One Grams of Spirit and Seven Ounces of Desire.” You can reach her at sciencesolitaire@gmail.com.