Before you grab your morning cup of coffee, think about the effect it is going to have on your body. You drink it because it is going to help wake you up, maybe even give you some energy, but the caffeine in your coffee is a drug that causes many metabolic effects. These metabolic effects include stimulation of your central nervous and urinary systems as well an increase in fatty acid metabolism.
Hypertension
High blood pressure is a common heart problem in America. Caffeine can exacerbate this problem. When you consume caffeine, both your systolic and diastolic pressures rise. Just two to three cups of coffee can cause a rise between 3 and 14 mmHg in systolic pressure or 4 and 13 mmHg in diastolic pressure.
Arrythmias
An arrhythmia occurs when the connection between the pacemaker cells of your heart and the rest of your cardiac cells fails. In a normal functioning heart, a spontaneous depolarization of the SA node cells inside your atrium conducts and facilitates the contraction and pumping action of the heart; however, when you have an arrhythmia, this connection malfunctions, for example, if the cardiac cells contract before they are signaled to or if there is a blockage between the SA node and the cardiac cells. Ingesting an excessive amount of caffeine may lead to a heart arrhythmia, some of which may be dangerous.
Physical Stress
A study conducted by the Duke University Medical Center in 1999 found that habitual morning caffeine produces a rise in the production of the adrenaline and noradrenaline your body produces and excretes. These two hormones induce a stress reaction by the body, including to the heart. The study monitored physiological responses to caffeine in 72 individuals for 2 weeks. Subjects were evaluated on both days caffeine was ingested and days when it was not. Day in and day out, physical stress like this is hard on the heart and can lead to heart disease.
Recommendations
Most health professionals agree that a moderate intake of caffeine can be perfectly safe for most. Moderate intake is equal to 200 mg of caffeine per day, or about two cups of coffee. If you have already been diagnosed with heart disease or hypertension, check with your doctor concerning the safest amount of caffeine for you.
References
- American Heart Association: Caffeine
- Mayo Clinic: Caffeine: How Does it Affect Blood Pressure?; Sheldon G. Sheps, M.D.; November 14, 2009
- Cleveland Clinic: Management of Arrythmias; August 2010
- "Anatomy and Physiology"; Kenneth S. Saladin; 2004
- Science Daily: Morning Coffee Boosts Blood Pressure, Stress Hormones All Day; March 1999
- Mayo Clinic: Stress: Constant Stress Puts Your Health At Risk; September 2010
