I somehow manage to squeeze onto the packed metro. I’m jammed in between the door and the countless people annoyedly gazing in my direction. I am overwhelmed. Right when I think this is the extent of this morning’s stimulation, the sound of accordion song busts into my ears. These chaotic metro rides were exciting during the first week or so in Paris; they were part of getting immersed in the culture! However, the honeymoon phase ended, and the metro became more stressful than exhilarating. That’s when this past weekend came to the rescue, providing a much needed break from the hectic, bustling Paris. The class took a trip to Provence, a region in southern France known for its colorful countryside, Roman architecture, and extensive art history. The difference in lifestyle was immediately noticeable. Everyone went about their day in a much more relaxed manner; there was no concept of time. This was quite the contrast from Paris, the city where everything is done in a rush. Whether you are navigating the crowded streets or shoving your way onto the metro, it seems you never get a break from the constantly accelerating Parisian lifestyle.
Cinematic shots in Avignon
Mullerthal region of Luxembourg, known for its impressive rock structures
The trip to Provence left me feeling refreshed. It was as if all the stress accumulated from the prior two weeks had been erased, and I was returning to Paris with a clear head. This made me realize how powerful the suburbs and nature can be towards influencing one’s mood. Most notably, when we visited the Pont du Gard aqueduct during the trip, the pristine, never ending river made me feel completely at peace. I couldn’t get enough, though, so I went for a hiking trip in Luxembourg this weekend and the nature had the same restorative effect. This made me question the effects of living in the city versus living in the suburbs. If just two days away from the city can be like hitting a reset button, are there permanent effects or consequences from living in one environment or the other? There have been various findings that suggest that urban living may pose a threat to our health.
At Pont Du Gard
Studies suggest that we undergo neurological and behavioral changes due to living in evolutionarily unfamiliar settings (cities) (Lambert et al., 2015). Research on this topic dates all the way back to 1868, when Charles Darwin found that the brains of domesticated rabbits were smaller than those of wild rabbits (Darwin, 1868). About one hundred years later, in 1972, there was a study that compared mice brains in natural and artificial environments. The natural environment had things such as logs and tree branches, whereas the artificial environment consisted of plastic toys. Mice were allowed to live in either of these environments for four to ten weeks, and were then autopsied. The results showed that the naturally-enriched group showed higher levels of DHEA, a hormone linked with positive health influences such as more emotional resilience (Starka et al., 2014; Rosenzweig et al., 1972). There is even evidence in humans of the positive neural effects of nature and the negative effects of urban environments. For example, humans showed an increase in prefrontal cortex activity when viewing an actual plant compared to viewing an image of that same plant (Igarashi et al., 2014). Furthermore, a recent study from the UK suggests that children raised in urban environments are at an increased risk for psychotic symptoms, such as anxiety, depression, and schizophrenia (Newbury et al., 2016). These findings are theorized to be due to lower social cohesion paired with more crime victimization seen in urban neighborhoods (Newbury et al., 2016).
The various forms of pollution experienced in urban environments also have a negative influence on our overall health. Light pollution is no exception. Light exposure at night interferes with the body’s natural circadian rhythm (McClung, 2007), in turn interfering with hormone secretion and other physiological processes (Stevens et al., 2013). This can pose serious health problems. For example, a 2008 study found a strong correlation between light at night and breast cancer incidence in about 150 different communities (Kloog et al., 2008). Animal studies have shown similar results, too. A study on hamsters in which they were exposed to constant light, both at night and day, caused them to show less locomotor activity, less preference for a sucrose solution, and dampened daily cortisol rhythms compared to control mice living in an environment with a natural lighting pattern (Bedrosian et al., 2013). These symptoms are considered to be representative of depression (Bedrosian et al., 2013). Light pollution is thus another factor of urban living that may lead to diminished mental and overall health.
A map of the world’s light pollution
All the studies discussed above make urban living sound quite horrific, but it should be mentioned that it is difficult to draw broad conclusions from them that can be applied to our lives as humans. For example, in field studies done on humans, the samples taken usually represent small populations and it is almost impossible to control for confounding variables. In the studies done in the lab, on both humans and animals, it is impossible to recreate the environments and experiences that everyday life provides us with. This being said, these findings do still suggest that urban living could pose health concerns to us, and possibly future studies will be more conclusive.
Although city life has its perks, such as better access to health care and more job exposure, both past and recent research suggest that an occasional break from the scurry of everyday life certainly wouldn’t hurt.
Sources:
Bedrosian TA, Galan A, Vaughn CA, WeilZ M, Nelson RJ. Nocturnal light alters diurnal patterns of cortisol and clock proteins in female hamsters. J Neuroendocrinol. 25:590–0606. (2013).
Darwin C. The variation of Animals and Plants under Domestication. 1s. London: John Murray; (1868).
Igarashi M, Song C, Ikei H, Miyazaki Y. Effect of stimulation by foliage plant display images on prefrontal cortex activity: a comparison with stimulation using actual foliage plants. J Neuroimaging. (2014).
Joanne Newbury, Louise Arseneault, 1 Avshalom Caspi, Terrie E. Moffitt, Candice L. Odgers, and Helen L. Fisher. Why Are Children in Urban Neighborhoods at Increased Risk for Psychotic Symptoms? Findings From a UK Longitudinal Cohort Study. Schizophr Bull. 42(6): 1372–1383. (2016).
Kelly G. Lambert, Randy J. Nelson, Tanja Jovanovic, and Magdalena Cerdá. Brains in the City: Neurobiological effects of urbanization. Neurosci Biobehav Rev. 58, 107-122. (2015).
Kloog I, Haim A, Stevens RG, Barachana M, Portnov BA. Light at night co-distributes with incident breast but not lung cancer in the female population of Israel. Chronobiol Int. 25:65–81. (2008).
McClung CA. Circadian genes, rhythms and the biology of mood disorders. Pharmacol Ther. 11:222–232. (2007).
Rosenzweig MH, Bennett EI, Diamond MC. Brain changes in response to experience. Scientific American February. 22–30. (1972).
Starka L, Duskova M, Hill M. Dehydroepiandrosterone: a neuroactive steroid. J Steroid Biochem Molecul Biol. (2014).
Stevens RG, Brainard GC, Blask DE, Lockley SW, Motta ME. Adverse health effects of nighttime lighting: comments on American Medical Association policy statement. Am J Prev Med. 45:343–346. (2013).
Image: https://brilliantmaps.com/light-pollution/
