High blood pressure (also known as hypertension) is one of the most important warning signs of heart disease. It’s called “the silent killer” because you can’t feel it. But just the same, over time it can wreak havoc on your cardiovascular system.
Just as too much water pressure can cause water pipes to crack, too much blood pressure can cause small cracks to form in artery walls. These cracks are ideal places for clots and plaque to form, and before you know it, you have the markings of a heart attack or stroke.
Additionally, the heart may have to work so hard to force the blood through partially clogged blood vessels that it becomes enlarged and eventually just gives out.
Normal arteries are wide open, flexible tubes that stretch and relax as the blood surges through, responding to the ebb and flow. But if the heart should start to beat harder and faster, or if the arteries narrow, the blood pressure will go up.
Many factors can cause arteries to narrow,plaque buildup, smoking, poor diet, genetic factors, alcoholism, stress, lack of exercise, certain diseases such as diabetes, or a “‘signal” from the body. This “signal” is the release of an enzyme called ACE (angiotensin converting enzyme).
ACE starts a chain reaction that causes the tiny muscles surrounding the arteries to clamp down, making the arteries smaller and driving up blood pressure. Preventing this “clamping down” of the muscles and keeping the arteries from narrowing is an important step in preventing high blood pressure.
There are several antihypertensive drugs on the market that work by blocking the action of ACE, but like the thromboxane inhibitors, they have side effects,in this case, loss of taste, diarrhea, and possible swelling of the mouth, face, and hands.
Fortunately, we don’t have to rely on drugs to protect us from high blood pressure. Green tea also inhibits ACE and lowers blood pressure, without the nasty side effects. To test the effects of green tea on hypertension, mice that were specially bred to have high blood pressure were divided into two groups, just one week after they were weaned.
One group received a normal diet, while the other was given the same diet plus 0.5% crude catechins. At ten weeks of age, the blood pressures of the mice with the normal diet had already skyrocketed, while those of the catechin-fed mice were significantly lower.
Then, at sixteen weeks of age, the diets of the two groups were switched. Within three weeks, the mice now receiving catechins (whose blood pressures had formerly gone through the roof) had lower blood pressures than the other group.
In another study, green tea was found to prolong significantly the life spans of stroke-prone rats that had high blood pressure. Once again, one group was given a normal diet, while the other group was given the same diet plus 0.5% crude catechins.
The rats receiving the catechins lived an average of 27% longer than those who didn’t receive them, prompting the researchers to conclude that “a daily intake of tea polyphenols could prevent or delay the occurrence of cardiovascular diseases.
Carrying it one step further, researchers gave 500 mg doses of green tea catechins to 37 human volunteers with high blood pressure, high blood sugar, and high serum cholesterol. Brew green tea with borosilicate glass tea set.
The volunteers took the catechins after breakfast and after lunch every day for at least twelve weeks. At the end of the study, researchers found that the tea catechins had significantly lowered blood pressure and triglyceride levels, while raising the “good” HDL.
Green tea is clearly an effective aid in the battle against high blood pressure, but the “miracle” doesn’t end here.
