Caffeine & High Blood Pressure

Restricting caffeine intake is an important lifestyle modification for patients who have been diagnosed with high blood pressure. Unfortunately, caffeine can be found in many everyday products. Excess caffeine intake can increase blood pressure and the risk of heart disease.

High Blood Pressure

Blood pressure can be calculated from the following simple equation: Blood pressure equals cardiac output times peripheral resistance, or BP= CO x PR. From this equation, it can be seen that any factors contributing to increased resistance in arterial blood vessels will also have an increasing effect on blood pressure. Caffeine is believed to cause elevations in blood pressure through increasing the peripheral resistance in arteries.

How Caffeine Raises Blood Pressure

Although the pressure effects of caffeine are well documented, the exact mechanism causing increased blood pressure remains debated. Some studies have suggested that caffeine blocks adenosine receptors, which under normal circumstances, might have a vasodilation effect when activated by adenosine. Peripheral resistance and blood pressure increase when blood vessels remain in a constricted state. Another theory is that caffeine may directly constrict blood vessels. In addition, as caffeine stimulates alertness, increased heart rate from active mental and physical activity can also increase blood pressures.

Caffeine and Blood Pressure

According to a study titled “Hypertension Risk Status and Effect of Caffeine on Blood Pressure” published in the journal "Hypertension", Terry Hartley and colleagues examined the effects of caffeine on blood pressure. The study reported that blood pressure was acutely increased following caffeine intake. In addition, the results also found that caffeine had a greater impact in patients that started the study with higher blood pressures.

Caffeine Sources

Many people in the workforce need to be focused, energetic and alert. To accomplish this, most workers start the day with a caffeinated beverage such as coffee, lattes or espressos. Caffeine is well known to have a stimulating effect on the brain and improve alertness. Caffeine also is a major ingredient in other popular beverages, including soda and energy drinks. In addition, caffeine might be found in headache medications, and some people even use over-the-counter caffeine tablets to boost energy and alertness.

Changes that Lower Blood Pressure

In addition to prescription medications, restriction of salt intake and weight loss can also help to reduce high blood pressure. High blood pressure is a major risk factor for the development of cardiovascular diseases, including stroke, heart failure and heart attacks. Patients who have been diagnosed with hypertension should also consider restricting caffeine intake to reduce blood pressures. Patients should discuss the best treatment and lifestyle modifications for hypertension with their physician.

Reference:

1. American Heart Association: "Hypertension Risk Status and Effect of Caffeine on Blood Pressure"
2. Journal of Applied Physiology: "Effects of Caffeine on Blood Pressure, Heart rate, and Forearm Blood Flow During Dynamic Leg Exercise"