High Blood Pressure
A blood pressure reading tells the amount of force, or pressure, with which the blood is pumping against the walls of the arteries. The systolic (top) number is the force of the blood when the heart pumps, and the bottom (diastolic) is the force of the blood when the heart is at rest. The Center for Disease Control (CDC) defines high blood pressure when the systolic reading is above 140 and the diastolic is above 90. There are many factors that can affect blood pressure, such as smoking, obesity and stress. Another possible factor that has conflicting evidence is coffee consumption.
Conflicting Research
"Entrepreneur" magazine lists coffee as the most popular drink in the world, second only to water, yet many wonder if they should continue to consume it after hearing negative reports on how coffee affects blood pressure. One such study, published in the "European Journal of Clinical Nutrition," states that coffee consumption has a negative effect on high blood pressure, especially for those who are prone to it due to other risk factors.
A more recent study published in the "Journal of Hypertension" found that when they separately tested the effects of caffeine and caffeinated coffee on blood pressure, caffeine raised blood pressure significantly, but caffeinated coffee showed only a small increase in blood pressure. This could be due to the fact that coffee has also been shown to contain a number of antioxidants, which can protect the body from heart disease, as reported in study published by the National Institute of Health.
Putting It Together
With all of the conflicting studies, the American Heart Association has taken a bottom line stance and declared that they see no problem or ill effects from drinking one to two cups of coffee per day. This is supported by researchers at Harvard University, who found no relevant rise in blood pressure associated with coffee drinking, and actually found that consuming coffee on a regular basis could possibly lead to protection from high blood pressure.
The best way to determine whether or not coffee will affect your blood pressure is to take a reading with a home BP monitor before consuming coffee, and then taking another reading 30 minutes and 60 minutes after consumption. Do not engage in strenuous activity within that hour, or eat heavy or salty foods. Record your readings, and you will be able to tell if you should be drinking coffee or not.
