Coffee is one of the most consumed drinks in the world. The active ingredient in coffee is caffeine, a slightly bitter-tasting substance that has an excitatory effect on the nervous system. Drinking coffee stimulates the brain, leading to an increase in alertness. Although in most cases it is relatively harmless, some individuals may experience adverse effects from ingesting too much coffee. Caffeine has been linked to a number of medical side effects which may be harmful for some individuals.
Dependence and Addiction
One medical effect of long-term consistent coffee use is caffeine dependence and addiction. Caffeine stimulates the central nervous system by altering the signaling of depressants within the brain, which is part of why caffeine acts as a stimulant. Over time, the central nervous system becomes used to the presence of caffeine for alertness, and undergoes changes in the absence of caffeine that lead to unpleasant side effects. This is known as caffeine dependence. Caffeine withdrawal can lead to headaches, difficulty concentrating, depression and fatigue, according to Brigham Young University.
In extreme cases, habitual caffeine users may become addicted to caffeine. In addition to the physical dependence on caffeine stimulation, users may experience neurological changes within the brain that lead to psychological cravings for caffeine. Caffeine dependence and addiction can be treated by abstaining from caffeine use.
Hypertension
Drinking coffee can also lead to hypertension, or high blood pressure. High blood pressure occurs as a result of caffeine for a range of reasons. Caffeine may prevent the action of vasodilators, chemicals that cause the blood vessels to widen, decreasing blood pressure. Caffeine also stimulates regions of the brain that release excitatory chemicals, which can increase heart rate and blood pressure, according to the Mayo Clinic. This medical side effect of coffee has been linked to hypertension in both adults and children. Individuals with a history of hypertension, or people at increased risk of high blood pressure, should carefully monitor their coffee intake and consider switching to decaffeinated coffee.
Anxiety
Excessive or prolonged coffee use can lead to anxiety in some individuals. Anxiety is characterized by an increased heart rate, trembling, shortness of breath, as well as mood swings and anger. Drinking coffee may contribute to anxiety in individuals already prone to the condition, since caffeine activates stimulatory pathways within the brain that can increase heart rate. Ingesting too much caffeine can lead to other symptoms of anxiety, such as trembling.
According to the American Institute for Preventive Medicine, caffeine withdrawal can also lead to anxiety, since the body is under stress in the absence of caffeine. Individuals predisposed to anxiety disorders should severely limit their coffee intake, or switch to decaffeinated coffee.
