Green tea or black tea, which one is better for people with high blood pressure?

Green tea and black tea are both among the teas we drink most often. However, for those who are sensitive to high blood pressure, they need to pay more attention to their diet. So which tea, green tea or black tea, is more suitable for people with high blood pressure?

Green tea or black tea, which one is better for people with high blood pressure?

Green tea is an unfermented tea, and during the processing, about 90% of its tea polyphenols are retained; black tea is a fermented tea, and during the processing, about 90% of its tea polyphenols are reduced. The difference in their main ingredients lies in the amount of tea polyphenols they contain. Based on the existing evidence, tea polyphenols can produce effects similar to angiotensin converting enzyme inhibitors after entering the human body, inhibiting angiotensin converting enzyme, dilating blood vessels, and lowering blood pressure. This is similar to the antihypertensive mechanism of pril antihypertensive drugs. Therefore, the difference in tea polyphenol content between green tea and black tea may lead to slightly different effects on blood pressure: the former has a high tea polyphenol content, which may slightly lower or stabilize blood pressure; the latter has a low tea polyphenol content, which may stabilize blood pressure from rising. However, the authenticity of their effects on blood pressure remains to be verified. After all, other ingredients contained in black tea and green tea may also have a certain impact on blood pressure. The exact impact on blood pressure after drinking may also vary from person to person. Medical experts make no conclusion or recommendation here.

It should be noted that people with high blood pressure should try to drink light tea and less strong tea. Because tea is rich in caffeine, it can excite the central nervous system and bring the benefit of refreshing you. However, for people with high blood pressure, consuming too much caffeine can increase blood pressure, which is not conducive to blood pressure control. Compared with light tea, strong tea has a higher caffeine content and is not suitable for people with high blood pressure. But many friends like to drink strong tea, which may be related to the refreshing effect of strong tea. Here, Medical Science does not recommend friends to drink strong tea, because strong tea not only affects blood pressure, but also affects our digestive system. Especially for patients with gastroesophageal reflux disease and peptic ulcer, it is not recommended to drink it, which may aggravate the condition.

Tea time arrangement

Some old tea drinkers often make the following arrangements for drinking tea throughout the year:

Drinking scented tea in spring and autumn is warm and fragrant;

Drinking green tea in summer, or adding a few chrysanthemums, honeysuckle, or a few drops of lemon juice or mint juice to green tea, can enhance the cooling effect.

Drinking sugared black tea or milk black tea in winter has the effect of soothing the stomach and warming the body.

Some people drink different teas at different times of the day.

Drink a cup of light high-grade green tea in the morning to refresh your mind;

Drinking a cup of jasmine tea in the morning is fragrant and pleasant, which can improve work efficiency;

Drink a cup of black tea in the afternoon to relieve fatigue and refresh yourself;

During the afternoon break, drink a cup of milk tea or a cup of premium green tea with some snacks or fruits to supplement your nutrition;

What are the differences between black tea and green tea?

First of all, whether it is black tea or green tea, it is made from the leaves of the tea tree. Generally speaking, there are three types of tea that we come into contact with the most, namely: green tea, black tea and oolong tea. Although they are all called "tea", they are very different. The difference between them mainly depends on how the tea is processed. For example, partially fermented leaves produce oolong tea; fermented leaves produce black tea; and unfermented leaves produce green tea.

Secondly, whether it is fermented black tea or unfermented green tea, the main flavonoids they contain are flavanols, such as epigallocatechin-3, epigallocatechin-3 gallate, epicatechin-3 gallate and epicatechin-3. Although the total flavonoid content in green and black tea is similar, their chemical structures are different. This is largely due to the oxidation process used in black tea production, which converts flavonoids (such as catechins in green tea) into more complex varieties, such as thearubigins and theaflavins.

In green tea, catechins make up about 80% to 90% of the total flavonoids, while in black tea, catechins make up 20% to 30% of the total flavonoids. That is, green tea contains more catechins than black tea. Catechins are powerful antioxidants both inside and outside our bodies. In addition, green tea is a type of unfermented tea, which can be simply said to be a natural tea. It is produced from freshly picked leaves of the tea plant and has a high vitamin and mineral content. Drinking a certain amount every day can provide 5% to 10% of a person's daily requirement of riboflavin, niacin, folic acid and pantothenic acid.

Finally, there are differences in the caffeine content of black tea and green tea. Although the actual caffeine content will vary depending on the source of the tea, processing and preparation methods, each cup of green tea naturally contains about 25 mg of caffeine, which is much less than the caffeine content of black tea, about one-third. Moreover, the caffeine content in black tea increases with the steeping time.

Green tea is a non-fermented tea, while black tea is a fermented tea. The ingredients of the two are different.

my country's tea culture spans five thousand years in China and has a long history. It has developed into many varieties. Black tea and green tea may be the varieties that everyone is most familiar with. One is mild and mellow with a bright red soup; the other is fragrant and refreshing with an emerald green soup. Everyone has their own preferences for these two types of tea. But from the perspective of prevention and treatment of hypertension, the two have different ingredients and the effects are different. Let’s take a closer look.

There are many ways to classify tea in my country. According to the tea processing method, it can be divided into raw tea and refined tea; according to the tea picking season, it can be divided into spring tea, summer tea, autumn tea and winter tea; according to the degree of fermentation, it can be divided into non-fermented tea such as green tea, semi-fermented tea such as white tea, fully fermented tea such as black tea, and post-fermented tea such as dark tea. What is relevant to the prevention and treatment of hypertension is the degree of fermentation of tea, which has different ingredients.

Green tea is unfermented tea and is the representative tea drink in my country. Green tea is made from unfumigated and unoxidized leaves. After the tea leaves are picked, they are immediately evaporated or heated to destroy the enzymes that cause oxidation. The polyphenols in the fresh leaves are retained, keeping the color green. They are then dried and stored. Compared with black tea, green tea undergoes the least processing, which maximizes the retention of the beneficial ingredients of tea. The effective ingredients such as tea polyphenols, caffeine, chlorophyll, catechins, vitamins, minerals, etc. are almost not lost, but it also contains more tannic acid and phytic acid.

Black tea is a fermented tea. After fresh tea leaves are picked, they go through processes such as withering, rolling, fermentation, and drying. Among them, the most critical process is fermentation. The fermentation process is the process of oxidation of polyphenols. Polyphenols are destroyed to varying degrees during the oxidation process.

After tea is fermented, the tannic acid and phytic acid content decreases, the bitterness decreases, and more ingredients such as thearubigins, theaflavins, amino acids and B vitamins are produced.

Precautions for patients with hypertension to drink green tea

People with weak spleen and stomach can drink green tea after meals. In traditional Chinese medicine, green tea is cold in nature. Modern medicine has confirmed that green tea contains more tannic acid and phytic acid, which can cause great irritation to the gastrointestinal tract. People with poor gastrointestinal function may experience gastrointestinal discomfort or even abdominal pain when drinking green tea on an empty stomach. It is recommended to drink it after a meal. Drink black tea if you are on an empty stomach.

People with sensitive skin should not drink green tea before going to bed. Green tea contains a certain amount of caffeine, which can easily cause sympathetic nerve excitement. People who are sensitive to caffeine may suffer from insomnia if they drink tea before going to bed. I am one of these people and never dare to drink tea at night.

Do not take blood-enriching medicine with tea. The tannic acid in tea can affect the absorption of iron ions. Most blood tonics contain iron supplements. People who are taking blood tonics should not take them with tea to avoid affecting the efficacy of the medicine.

Which one is more suitable for patients with hypertension, black tea or green tea?

In the above, I have described in detail the simple differences between green tea and black tea. I believe you can also see some facts, that is, compared with black tea, green tea is obviously the best choice for us patients with hypertension. In fact, a meta-analysis of multiple observational studies suggests that:

One cup of green tea a day was linked to a 10% lower risk of coronary artery disease.

In addition, a recent meta-analysis found that:

Drinking green tea can improve control of both systolic and diastolic blood pressure. The beneficial effects were particularly significant in subjects with stage 1 hypertension or prehypertension.

In fact, the potential mechanisms for the beneficial effects of green tea on blood pressure control are multifaceted. First, green tea extract can maintain vasodilation by balancing vasoconstrictor substances, such as angiotensin II, prostaglandins, endothelins, etc., or vasodilator substances, such as prostacyclin and various endothelium-derived hyperpolarizing factors.

Second, green tea may improve ventricular function and exert beneficial effects by increasing nitric oxide production from endothelial cells in a PI3 kinase-dependent pathway. Finally, green tea can reduce the production of oxidative stress by inducing antioxidant enzymes. In addition, green tea catechins can induce anti-inflammatory effects through the inhibition of several inflammatory factors, such as cytokines, adhesion molecules, and nuclear factors.

Although drinking green tea can improve blood pressure, high doses of green tea may contain a large amount of caffeine, which may lead to increased blood pressure. From this perspective, long-term and excessive intake of green tea is not conducive to blood pressure control. In addition, when we are diagnosed with high blood pressure, we should not put all our hopes on green tea, but should follow the doctor's advice and learn to use medication as the main method and lifestyle regulation as the auxiliary method.

What should we pay attention to when drinking green tea?

Green tea has many health benefits when consumed in moderation. However, studies have shown that higher doses may cause some known and unknown adverse reactions. Since green tea contains caffeine, catechins and tannins, drinking large amounts of tea may cause neural tube birth defects in infants due to folic acid antagonism. Therefore, pregnant women should drink tea with caution, and it is recommended not to exceed 1 cup.

When consumed as a beverage, green tea is considered safe in moderate amounts. However, there is concern that green tea supplements containing high amounts of epigallocatechin gallate (EGCG) may cause liver damage, especially if taken in amounts exceeding 800 mg per day. In daily life, each cup of brewed green tea contains 50-100 mg EGCG, so to be safe, we should consume less than 8 cups of green tea.

With the exception of decaffeinated green tea products, green tea contains large amounts of caffeine and too much caffeine. The caffeine content is a stimulant and may cause adverse health effects in some people. In fact, consuming too much caffeine can make people feel jittery and shaky, which can disrupt our sleep and cause headaches. In addition, people with heart disease or severe cardiovascular disease should not drink green tea.

Some studies have shown that tea plants have the ability to accumulate high levels of aluminum. This aspect is very important for people with kidney failure, because aluminum can accumulate in the body and cause neurological diseases. Therefore, it is necessary for us to control the intake of this metal. At the same time, green tea catechins may have an affinity for iron, and green tea intake can lead to a significant decrease in the bioavailability of iron in the diet, thereby inducing iron deficiency anemia.

To sum up, whether you have high blood pressure or are a normal and healthy person, drinking tea is a good habit. However, drinking tea has both advantages and disadvantages to our health. Each of us should be able to see both sides of it, so as to abandon the harmful side of green tea and maximize the benefits of green tea to us. The biggest principle to maximize the benefits is not to drink too much, but to drink in moderation.

For many of us, drinking tea is a calm, peaceful part of our day. Even if tea itself doesn't have any health benefits, taking the time to simply brew a cup of tea and enjoying each sip can bring a sense of peace and well-being. There’s a good chance there’s medicinal value in our cups, too, as many types of tea have a long history of health benefits. However, since there is little solid evidence to support the true health benefits of tea, it is unwise to rely solely on tea to treat, prevent, or manage disease. If we are managing high blood pressure, we must work with our attending physician to develop a reasonable and correct plan. This is the wisest way to control blood pressure.