The caffeine in a person's coffee, tea, soft drinks, dietary supplements or energy drinks may cause adverse physiological side effects. Caffeine can negatively impact a person's blood pressure, heartbeat and quality of sleep. It is also potentially addictive. If you have heart disease, high blood pressure, trouble sleeping, or are pregnant, you may wish to limit or avoid caffeine. For best results, seek guidance from your doctor prior to increasing or decreasing caffeine in your diet.
Increased Blood Pressure
As a stimulant, caffeine may have a heightening effect on a person's blood pressure. According to Mayo Clinic hypertension specialist, Sheldon G. Sheps, M.D., the amount of caffeine in 16 to 20 ounces of coffee can raise a person's systolic pressure (the top number in a blood pressure reading) 3 to 14 millimeters of mercury (mm Hg). The diastolic pressure (the bottom number) may increase 4 to 13 mm Hg. This may occur whether a person already has high blood pressure or not. In addition, Sheps explains that regular coffee drinkers may have higher blood pressure than non-coffee drinkers.
Arrhythmia
Caffeine consumption may cause arrhythmia, or irregular heartbeat. According to the American Heart Assocation, arrhythmias are common, affecting more than 2.2 million Americans at any given time. Cardiovascular experts at the Cleveland Clinic suggest that a variety of factors contribute to these arrhythmias. Caffeine intake may trigger or worsen the condition in some people. Symptoms of an arrhythmia include heart palpitations, a "fluttering" heart rate, pounding in the chest, dizziness, lightheadedness, shortness of breath, weakness and fatigue.
Sleep Disruption and Daytime Sleepiness
Caffeine can contribute to sleep problems during the night and, as a result, sleepiness during the day. According to research published in the "Journal of Psychopharmacology" in July 2009, people who consume 150 milligrams of caffeine per day (the amount found in roughly 2 cups of coffee) experience reduced quality in every stage of nightly sleep. These effects replicate physiological symptoms of insomnia--a chronic inability to sleep. Following days of disrupted sleep, people often exhibit reduced ability to focus or remain fully alert. While people vary in their sensitivity to caffeine, it does appear to have a negative impact on nighttime sleep and daytime alertness.
Physical Dependence
People who experience headaches or irritability when their morning coffee is delayed may have a physical dependence. According to an article published in "U.S. News and World Report" in June 2009, most avid coffee drinkers experience mild to moderate withdrawal from caffeine every night, which is remedied by drinking coffee, or an alternate caffeine source, in the morning. Roland Griffiths, a professor of psychiatry and neuroscience at the Johns Hopkins School of Medicine suggests that caffeine withdrawal symptoms are similar to those of classic drug addiction. Symptoms may include headache, lethargy, depressed mood, nausea, vomiting, muscle pain and muscle stiffness. If you experience any one of these symptoms when you don't have caffeine, it could indicate a physical dependency.
References
- Mayo Clinic: Caffeine and Blood Pressure
- Cleveland Clinic: Management of Arrythmias
- American Heart Association: Arrythmia Facts
- Journal of Psychopharmacology: Effects on sleep stages and microarchitecture of caffeine and its combination with zolpidem or trazodone in healthy volunteers, Jul. 2009
- U.S. News and World Report: 6 Signs of Caffeine Addiction, January W. Payne, June 2009
Member Comments