Statistics from the American Heart Association indicate that more than one in three adult Americans has some form of cardiovascular disease. Many suffer from high blood pressure, while others have coronary artery disease or have been diagnosed with heart failure or suffered a heart attack. Many risk factors for heart disease are known, including smoking, poor diet, high cholesterol and a family history of heart problems. Researchers have examined whether caffeine consumption raises the risk of heart disease. While caffeine does affect certain heart functions, it does not appear to cause higher incidence of heart disease.
Caffeine Effects
Caffeine is absorbed very quickly after being ingested and moves into the brain where it exerts most of its effect. It is a general stimulant of the nervous system, increasing alertness and providing quick energy. It also causes fat to be released from fatty tissue and has rapid effects on the kidneys. Caffeine causes increased output of urine and, if not accompanied with fluid intake, it may cause dehydration. MedlinePlus states that habitual or excessive caffeine consumption may cause an increased heart rate, restlessness, depression, tremors or wakefulness.
Caffeine and Heart Disease
Because caffeine affects the heart rate, many studies have searched for a link between caffeine and heart disease. In one study by Dr. E. Lopez-Garcia et al published in "Circulation" in 2006, more than 120,000 healthy men and women were studied for 20 years. No link between heart disease and caffeine consumption was found in this group. In another study of more than 45,000 men published by Dr. D. Grobbee et al in the "New England Journal of Medicine" in 1991, there was also no relationship between moderate caffeine intake and heart disease. Other studies drew similar conclusions, including one published in 2010 in which coffee drinking was associated with a lower rate of hospitalization for heart rhythm abnormalities.
Dietary Sources
Caffeine is a bitter-tasting substance that occurs naturally in a number of plants and fruits, including coffee and tea plants, the seeds of the cacao plant and in kola nuts. Dietary sources of caffeine include coffee, tea, many soft drinks, some chocolate products and some nuts. Both coffee and tea are available with reduced caffeine and also are available decaffeinated.
Other Sources
Caffeine is also added to over-the-counter medications including some pain relievers and cold medicines. It is also a component in many appetite-suppressant products and in products intended to increase alertness and provide energy. Because caffeine has no taste, always check product labels to determine whether caffeine has been added.
Recommendations
Caffeine produces side effects in some people, including a noticeably fast heart rate, sleeplessness or tremors. Abrupt withdrawal may result in headaches, irritability or drowsiness. MedlinePlus indicates that 1 to 3 cups of coffee daily is considered moderate consumption and 10 or more cups daily is excessive. Caffeine is not recommended for children, especially for those who are hyperactive, and pregnant women and people with coronary artery disease or peptic ulcers should only consume moderate amounts. There may also be interactions between caffeine and some prescription drugs. Discuss your intake of caffeine with your doctor to determine what is appropriate for you.
References
- PubMed: "Coffee, caffeine, and cardiovascular disease in men.", by Grobbee, D. et al, "New England Journal of Medicine", 1990.
- MedlinePlus: Caffeine
- MedlinePlus: Caffeine in the Diet.
- Black Health Magazine: Coffee Drinking And Caffeine Associated With Reduced Risk Of Hospitalization For Heart Rhythm Disturb
- Health Publications: Coffee, Caffeine and Cardiovascular Disease.
- PubMed: "Coffee Consumption and Coronary Heart Disease in Men and Women: A Prospective Cohort Study", by Lopez-Garcia, E. et al, "Circulation", 2006.
