With the addition of new coffee vendors on Emory’s campus over the past three years, combined with the excellent surrounding breakfast hotspots, I have become one to regularly appreciate and truly enjoy a hot cup of coffee. Whether the coffee be from Starbucks, Rise-n-Dine or Dunkin Donuts, I am victim to daily expenditure at these vendors for my morning (and sometimes evening) caffeine fix. Now that my time in Paris is approaching its end, I will readily admit that I had routed the closest Starbucks locations to my dorm and to the building where we take classes (before my departure from New York). I saved those directions in my phone; anticipating daily visits to this familiar coffee shop.
When I realized that it would be a daily struggle to somehow go to Starbucks before my early morning class (thanks to the reliability of the French subway system), I decided to give the conveniently located French coffee (on campus) a chance. My first experience with French café was at the Cite Universitaire cafeteria, as I was presented with a Dixie-cup size equivalent cup of black coffee. No sugar, no milk…but I was pleasantly surprised. I didn’t realize how strong the coffee would be and I can safely say that 3 cups of the café coffee was overkill…
All throughout Paris, I have noticed that the café comes in one size: about a quarter of the size of the regular coffee we get back in America. The coffee is quite deceiving, as the small cup actually keeps me energized despite its miniscule volume. I quickly realized that coffee in itself is a part of French culture, as many cafes throughout the city orient their tables and chairs to face the streets—this way, people can enjoy a cup of coffee and “people watch”. I rarely see Parisians eating lavish breakfasts (doesn’t stop me though…); rather, they enjoy a simple black coffee with the morning paper. French culture, to me, seems to emphasize simplicity and reservation. A cup of coffee, then, serves as a means to collect your thoughts and appreciate the beauty of France while simultaneously obtaining a needed jolt of energy. A cup of coffee transcends the traditional role of a breakfast drink, as “une tasse de café” is readily available (and encouraged) at any time of day.
One of the classes we are taking here is related to body enhancement and the new, innovative technologies that can alter normal human function. During class one day, Dr. Crutcher shared with us some research that suggested the caffeine fix from our morning cups of coffee actually yields some physiological effects besides just enhanced alertness. In the past, researchers found that caffeine can increase anxiety in the short run, but increased doses of caffeine over time (via more coffee, for example) can lead to a diminished effect because of the build up of tolerance (Rogers et al., 2010). Recent research suggests that caffeine, readily found in coffee, may modify the way the different brain areas react to social threats (Smith et al., 2012). What are the neurological implications of this? Smith et al. (2012) set out to determine if there really was a relationship between anxiety, threatening signals, caffeine and the brain.
How did they do this study? After obtaining a group of subjects, the researchers gave the participants in this study received a fixed amount of either caffeine or placebo in two different sessions. During each session, the participants were placed in an MRI machine that would give researchers an fMRI scan (functional magnetic resonance image). An fMRI is basically a way to measure the changes in blood flow in the brain. Changes in blood flow in the brain represent changes in activity and activation in the different areas of the brain. (For example, if an area of the brain is in use, then there is increased blood flow in that area.) While in the MRI machine, participants were asked to perform an “emotional face processing task” (EFPT). This task involved participants being presented with different faces, each representing different emotions, and they had to match the presented face to a target face at the top of the screen. (Similar to a matching game!) After seeing the faces and doing the matching task, the participants would rate their anxiety and mental alertness (compared to before the task) via a questionnaire. Researchers also measured their blood pressure (before and 2 hours after the treatment of either the placebo or caffeine) (Smith et al., 2012).
Turns out that when the participants who were administered caffeine saw the threatening faces, that is the angry and fearful faces during the EFPT, there was increased activation of a brain area called the “midbrain periaqueductal gray area” and decreased activation in another area called the “medial prefrontal cortex” compared to the placebo group (Smith et al., 2012). Participants who received the caffeine dosage had higher self-rated anxiety on the questionnaires and their diastolic blood pressures were higher also! However, the exact neural mechanisms and implications of how these areas actually process threatening images and scenarios are still unknown (Smith et al., 2012). So what was the point of this study then? Smith et al. (2012) suggest that these brain areas, that showed changes in activity, are actually related to social threat processing and anxiety in humans. Because there were actual changes in blood flow in these areas in response to threatening or anxiety-inducing faces, only in the light of a caffeine dosage, it seems to be that caffeine is modifying the patterns of activation in the brain. A daily dose of caffeine, in the form of coffee for most of us, then, can possibly affect the way we perceive threats and can possibly affect how anxious we are compared to when we do not consume caffeine.
As with almost everything that seems too good to be true, in this case a delicious cup of French coffee, this study seems to suggest that loading up on multiple cups of coffee a day might not be the best idea. But, I don’t really plan on giving up my black Americano any time soon (especially since I’m leaving France soon and am already having French coffee withdrawal).
Rogers, P, Hohoff C, Heatherley S (2010) Association of the anxiogenic and alerting effects of caffeine with ADORA2A and ADORA1 polymorphisms and habitual level of caffeine consumption. Neuropsychopharmacology 35: 1973–83.
Smith J, Lawrence D, Diukova A, Wise R, Rogers P (2012) Storm in a coffee cup: caffeine modifies brain activation to social signals of threat. Scan 7: 831-840