With over half of all American adults consuming caffeine on a daily basis, the United States has the highest level of caffeine consumption in the world. Caffeine is classified as a drug because it affects the central nervous system. Most of the effects of caffeine can be categorized as either physiological or psychological. Two of the most common physiological effects include an increase in heart rate and increased energy levels due to the release of glucose into the body. Psychological effects include enhanced mental alertness and the potential for dependence. While some of the effects of caffeine use are considered by people to be desirable, the possibility of caffeine dependence is a reminder to consumers that caffeine is a drug.
Increased Heart Rate
Consumption of caffeine blocks the neurotransmitter adenosine, resulting in the release of adrenaline by the adrenal glands. Additionally, caffeine blocks phosphodiesterase, an enzyme that helps the body maintain a normal heart rate. The end result of these blockages is a faster heart rate. Increased heart rate can occur within fifteen to twenty minutes of caffeine consumption and the effect can linger for hours.
Higher Energy Level
The consumption of caffeine increases both physical and mental energy levels. By stimulating the body’s release of adrenaline and other catecholamines, caffeine causes your heart to beat faster. This impact on the sympathetic nervous system results in the distribution of additional blood to muscles and the release of sugar into bloodstream for energy. This additional energy helps athletes improve their performance times in sports such as running and cycling. Additionally, caffeine’s positive impact on energy levels can help people sustain physical performance for longer periods of time.
Enhanced Mental Alertness
Studies of the psychological effects of caffeine indicate that caffeine can positively impact a person’s ability to process information and vigilance. Caffeine is also known to improve information processing and response times. The positive effects that caffeine has on mental alertness are related to caffeine’s ability to raise levels of dopamine, which is linked to concentration levels. Other studies indicate that caffeine can help preserve the memory skills of older adults.
Regular consumption of 100 mg caffeine per day can result in chemical dependence. In fact, caffeine intoxication and caffeine withdrawal are listed as official diagnoses in the DSM-5 (5th edition of the Diagnostic and Statistical Manual of Mental Disorders). Approximately one day after ceasing caffeine use, regular caffeine users may experience muscle fatigue, irritability and difficulty concentrating. Mild nausea, muscular pain and headaches may also result. Measures to prevent chemical dependence and subsequent withdrawal include using modest amounts of caffeine or consuming caffeine on an irregular basis. Ideally, the best way to prevent caffeine dependence is to completely refrain from ingesting caffeine in the first place.