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?

Tea is an unfermented tea. During the processing, about 90% of the tea polyphenols in green tea are retained; black tea is a fermented tea. During the processing, about 90% of the tea polyphenols in black tea are reduced. The difference between the main ingredients they contain lies in the amount of tea polyphenols. According to the current evidence, after tea polyphenols enter the human body, they can produce an effect similar to that of angiotensin converting enzyme inhibitors, inhibit angiotensin converting enzyme, dilate blood vessels, and lower blood pressure. This is similar to the antihypertensive mechanism of pril antihypertensive drugs. Therefore, the difference in the content of tea polyphenols between green tea and black tea may lead to a slight difference in their effects on blood pressure: the former has a high content of tea polyphenols, which may slightly lower or stabilize blood pressure; the latter has a low content of tea polyphenols, which may stabilize blood pressure. 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 effect on blood pressure. What kind of effect on blood pressure after drinking may also vary from person to person. Here, medical Shen does not make a conclusion or recommendation.

It should be noted that people with high blood pressure should try to drink light tea and less strong tea when drinking tea. Because tea is rich in caffeine, it can excite the central nervous system and bring the benefit of refreshing. However, for people with high blood pressure, excessive intake of 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. However, many friends like to drink strong tea, which may be related to the refreshing effect of strong tea. Here, Medical Shen 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 ulcers. It is not recommended to drink it, which may aggravate the condition.

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;

First of all, whether it is black tea or green tea, they are all made from the leaves of the Camellia sinensis plant. Generally speaking, there are three types of tea that we are most exposed to, 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 the processing method of the tea leaves. For example, partially fermented leaves produce oolong tea; fermented leaves produce black tea; and unfermented leaves produce green tea.

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

In green tea, catechins account for about 80% to 90% of the total flavonoids, while in black tea, catechins account for 20% to 30% of the total flavonoids. That is, green tea contains more catechins than black tea. Catechins are strong antioxidants in our body and outside the body. In addition, green tea belongs to a kind of unfermented tea, which can be simply understood as a natural tea. It is produced from freshly picked leaves of the tea tree and has a high content of vitamins and minerals. 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 amount of caffeine in black tea and green tea. Although the actual caffeine content varies depending on the source, processing, and preparation of the tea, 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. And the caffeine content of black tea increases with the increase of steeping time.

my country's tea culture has a history of 5,000 years and has developed into many varieties. Black tea and green tea are probably the most familiar varieties. One is mild and mellow, with a bright red soup; the other is fresh and fragrant, with a emerald green soup. Everyone has their own preferences for these two types of tea. However, from the perspective of preventing and treating high blood pressure, the two have different ingredients and different effects. Let's take a closer look.

There are many ways to classify tea in my country. According to the 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 black tea. What is related 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 of Chinese tea. Green tea is made from unfumigated and unoxidized leaves. After picking, the tea leaves are evaporated or heated immediately to destroy the enzymes that cause oxidation, so that the polyphenols in the fresh leaves are retained, keeping the color green, and then dried and stored. Compared with black tea, green tea has the least processing process, so that the beneficial ingredients of tea are retained to the maximum extent. 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 fermented tea. Fresh tea leaves are picked and then go through withering, rolling, fermentation, drying and other processes. Among them, the most critical process is fermentation. The fermentation process is the process of polyphenols being oxidized, and 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.

If you have a weak spleen and stomach, choose to 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 meals. If you are on an empty stomach, drink black tea.

People who are sensitive to caffeine 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 will suffer from insomnia if they drink tea before going to bed. I am such a person and I never dare to drink tea at night.

Do not drink tea when taking blood tonics. 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 drink tea to avoid affecting the efficacy of the medicine.

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, green tea is obviously the best choice for us patients with hypertension compared to black tea. In fact, according to a meta-analysis of multiple observational studies:

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:

Green tea consumption can improve control of both systolic and diastolic blood pressure, with the beneficial effects being more pronounced in subjects with stage 1 hypertension or prehypertension.

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

Secondly, green tea can improve ventricular function and exert beneficial effects by increasing nitric oxide production in endothelial cells in a PI3 kinase-dependent pathway. Finally, green tea is able to 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 consuming green tea can improve blood pressure, high doses of green tea may contain a lot of caffeine, which can lead to increased blood pressure. From this perspective, long-term and large 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 follow the doctor's advice and learn to use medication as the main method and lifestyle control as the supplement.

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

In addition to decaffeinated green tea products, green tea also contains a lot of caffeine and too much caffeine. The caffeine content is stimulating and may cause adverse health effects in some people. In fact, excessive caffeine intake can make people feel uneasy and shaky, which can interfere with our sleep and cause headaches. In addition, friends with heart disease or severe cardiovascular disease should not drink green tea.

Some studies have shown that tea trees have the ability to accumulate high levels of aluminum. This aspect is very important for people with renal failure, as aluminum can accumulate in the body, leading to neurological disorders. Therefore, it is necessary to control the intake of this metal. At the same time, green tea catechins may have an affinity for iron, and the intake of green tea can lead to a significant decrease in the bioavailability of iron in the diet, thus triggering iron deficiency anemia.

In summary, whether you have high blood pressure or are healthy, drinking tea is a good habit. However, drinking tea has both advantages and disadvantages for 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 excessively, 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 every sip can bring a sense of peace and well-being. It’s possible that there’s medicinal value in our cups, too, as many types of tea have a long history of health benefits. However, since there’s little solid evidence to support tea’s true health benefits, it’s unwise to rely solely on tea to treat, prevent, or manage disease. If you’re managing high blood pressure, working with your doctor to develop a plan is the smartest way to keep your blood pressure under control.