Caffeine is a mild stimulant that is present in coffee, tea, chocolate, and some carbonated beverages. Excessive consumption of caffeine in humans, is not suffering from hypertension, leads to increased irritability. Amount of caffeine in 2-3 cups of coffee can raise systolic (ie, upper) blood pressure at 3-14 mm Hg, and diastolic (bottom) at 4-13 mm Hg
Some people who do not use permanent caffeine-containing products (coffee, tea, drinks), caffeine can cause a temporary but sharp rise in blood pressure. What exactly is the cause of the sharp rise in pressure is unknown. Some researchers believe that caffeine is able to block the so-called adenosine receptors.
Adenosine - a biologically active substance, which keeps the lumen of the arteries in the expanded state. In addition, caffeine can stimulate the adrenal glands that secrete hormones into the blood, such as cortisol and adrenaline. And these hormones are known to raise blood pressure.
The results of various studies are rather contradictory. Some scholars argue that people who regularly consume foods that contain caffeine, increased blood pressure, compared with those who did not consume these products. At the same time, other researchers say that regular intake of caffeine in humans is developed tolerance to it, in connection with which this substance has no lasting effect on blood pressure.
In one study, which examined the effects of caffeine contained in drinks such as cola, with 155,000 women, an association of caffeine and high blood pressure. At the same time such a connection between coffee, caffeine and high blood pressure, have been identified. In fact, women who drank caffeinated coffee, the risk of hypertension was lower.
In a similar study that was conducted in 2007 found that women who drank every day for 6 cups of caffeinated coffee per day, the pressure was lower than that of those who daily drank 3 cups of coffee. It was also found that women and men who never drank coffee, the risk of hypertension was low.
Doctors recommend limiting caffeine intake to 200 mg per day. The average is 2 cups of coffee. Note that the content of caffeine in a cup of coffee can vary depending on the brand of coffee. Also, avoid caffeine immediately after training, resulting in increased blood pressure, and so (exercise, weight lifting, running, etc.).
To find out how and how much caffeine raises your blood pressure, measure it for 30 minutes before you drink coffee (or any other product that contains caffeine), and after 20-30 minutes. If blood pressure rises by more than 5-10 mm Hg, then it means that you are sensitive to caffeine.