High blood pressure can cause damage to your arteries, heart, kidneys, brain and even your eyes. According to the Center for Science in the Public Interest, four out of five Americans consume caffeine everyday. Coffee contains caffeine, which is linked to raising blood pressure. If you are at risk for hypertension or have already been diagnosed with it, you may want to evaluate your coffee-drinking habits.
Caffeine and Blood Pressure
According to a study conducted by Duke University in 2002, your morning coffee may be enough to affect your blood pressure all day long. Coffee raises your blood pressure above what it normally would be. Researchers began by exploring the effects of coffee on regular drinkers. Forty-seven coffee drinkers were given the caffeine equivalent to 4 cups of coffee on two days; then for the next two days they were given a placebo. Each of the days, the subjects had their heart rate and blood pressure monitored four times each hour from morning until bedtime. On the days the caffeine was administered, their blood pressure, heart rate and stress levels were all elevated. This was enough to make researchers believe that regular coffee drinking may have long-term negative health effects.
Blood Pressure Readings
According to Dr. Sheldon G. Sheps of the Mayo Clinic, coffee intake raises both your systolic and diastolic blood pressure. After drinking just 2 to 3 cups of coffee, your systolic pressure -- the top number of a blood pressure reading -- can increase from 3 up to 14 mmHg. Your diastolic pressure -- the bottom number -- can jump 4 to 13 mmHg after consuming coffee.
Mechanism
Though in many foods and drinks, caffeine is still considered a drug. It is a stimulant and works to increase your alertness, but it also increases your heart rate and blood pressure. The mechanism by which coffee raises your blood pressure is not fully understood. Caffeine may increase blood pressure by constricting your blood vessels, or the blood pressure increase may be due to the elevation in adrenaline hormones.
Implications
If you are someone who has been diagnosed with chronic high blood pressure, you may want to consider cutting back or stopping your intake of coffee. The drastic increase in blood pressure associated with coffee may be unsafe. If you are concerned about your intake of caffeine, consult your doctor for advice.
References
- Go Ask Alice; Caffeine's Effects on Health; June 20, 2008
- MayoClinic.com; Caffeine: How Does It Affect Blood Pressure?; Shelon G. Sheps; November 24, 2009
- "The Chronicle"; Caffeine Adds To Stress, Warn Scientists; Mike Miller; August 27, 2002
- "Nutrition: Concepts and Controversies"; Frances Sizer, Eleanor Whitney; 2004
