By Eugenie Bang, Northwestern University ’20
If America runs on Dunkin’, it is probably because of the college students buying coffee to survive their morning lectures from either an insane night of studying or partying- or in extreme cases, both. The National Coffee Association’s National Coffee Drinking Trends 2011 survey reveals that forty percent of the 18- to 24-year-olds reported that they drink coffee on a daily basis, an increase from the thirty-one percent in 2010. The drink has become a routine for many – some to the point of addiction. Although coffee does have negative effects, students should not feel guilty about grabbing that cup of Joe in the morning because moderate caffeine consumption has the potential to benefit them in the long run.
Before viewing the positive and negative aspects of coffee, the biology of sleep and how we try to overcome it must be understood. Adenosine is a compound found in our DNA that plays a major role by promoting sleep and decreasing arousal.1 In our brain, the amount of adenosine binding to its receptors rises as humans go about their daily activities. As the amount of binding increases, neuronal activity decreases, eventually resulting in sleep. However, an adenosine antagonist like caffeine, blocks adenosine from attaching to its receptors (A1 and A2A) by binding itself to these receptors first.1 The result is the prevention of adenosine from working properly; it can no longer bind to its receptors to promote drowsiness. A study reported that there is a significant increase in the density of adenosine receptors after frequent consumption of coffee, which means that more caffeine will be needed to block the increasing number of adenosine binding sites.2 This explains how people build a tolerance for caffeine, causing them to drink three or four cups of coffee a day just to feel the same effect, often leading to addiction.
Besides addiction, coffee has other negative side effects. One study showed how mice that consume caffeine develop short-term anxiety and noted that patients suffering from panic attacks or mental disorders are especially sensitive to small doses of caffeine.1 Long-term consumption of caffeine leads to less effective adenosine receptors,1 leading to many sleep disorders such as insomnia.1 Digestion problems can also arise from coffee, as it increases the production of stomach acid, especially if coffee is consumed first thing in the morning.1 If a high level of hydrochloric acid is produced because of coffee, then the body won’t be able to produce hydrochloric acid when it really needs it later on in the day. Furthermore, caffeine can result in heartburn as it relaxes the pressure on the lower esophageal sphincter, resulting in its inability to prevent the acidic stomach content from traveling back up the esophagus.3
Besides these unhealthy effects caffeine has on our body, moderate coffee consumption surprisingly has many health benefits, many of which are related to cognition. The enhancement in cognition is due to the ability of caffeine to block A1 adenosine receptors. These are located in the hippocampus and the cortex, which are the areas in the brain that control functions such as memory.1 By blocking adenosine from attaching to receptors in the hippocampus, caffeine suppresses sleepiness in areas controlling cognition. This results in memory enhancement. The Three City Study, an intensive study in Boston, Chicago, and San Antonio showed that among those over the age of sixty-five, more than three cups of coffee a day slow the decline of
verbal cognitive functioning and visuospatial memory.4 In a broader sense, coffee might even lower the risk of cognitive diseases such as Alzheimer’s disease. In a longitudinal study conducted by the Canadian Study of Health and Aging, risk of Alzheimer’s disease decreased by 31% in subjects over the age of sixty-five.4 One of the hypotheses that explains this phenomenon is the decreased risk of diabetes from consumption of caffeine. This is because diabetes has been linked to the occurrence of dementia.4 Coffee contains an abundance of magnesium, which is known to increase insulin sensitivity and the ability to effectively lower blood glucose levels- all of which help treat diabetes. 4 Caffeine has also been discovered to aid in areas other than cognition. Low doses of caffeine have been found to increase locomotor behavior in those with Parkinson’s disease, which stems from the blockade of A2A receptors in the brain.5 Caffeine was especially efficient for Parkinson’s patients in planting their heels on the ground while walking, which helps them walk more efficiently. 5
Although caffeine promotes anxiety and stomach indigestion in those who consume an excessive amount, studies show that moderate amounts of coffee could help reduce the likelihood of some diseases such as dementia and Parkinson’s disease. Anything in excess always leads to problems, but the future of coffee seems bright as more research is being done, revealing more possible benefits as time progresses. The newly discovered advantages of coffee have the potential to rehabilitate lives and not just to save a college student from an all-nighter.