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Tea can truly be called the national Russian drink.
Studies evaluating the effect of drinking tea as primary cardiovascular prevention are limited.
The authors of a new prospective cohort study assessed the association between tea consumption and the risk of atherosclerotic cardiovascular disease and overall mortality.
Does green tea help against cancer?
Catechins are also credited with unprecedented antioxidant properties that can protect the body from the effects of free radicals - molecules that damage healthy cells, due to which they can mutate, turn into cancerous ones and give rise to cancer.
However, firstly, the occurrence of cancer is a complex and difficult to explain process, and it is unlikely that its cause can be reduced to an insufficient amount of antioxidants. Secondly, everything in the body is too complex for us to say that antioxidants are an absolute good and free radicals are an absolute evil. Thus, the latter can destroy both healthy and malignant cells in the body. And antioxidants can ward off free radicals in both cases, says a study published
in the journal Science.
The Cochrane Library has twice conducted
analysis of scientific papers that assessed the connection between green tea and cancer prevention. In 2009, works were analyzed, the total number of subjects was 1.6 million people. Then experts found the research results contradictory and did not allow us to conclude that green tea really protects against cancer. By 2021, data had accumulated from an additional million people, but the conclusions remained the same: the effect of green tea on cancer prevention has not been proven, and if it does exist, it is insignificant.
Methods
The study included 100,902 adults from China who participated in the Prediction for ASCVD Risk in China (China-PAR) program. All individuals included in the study had lived in 15 Chinese provinces since 1998.
Information on tea consumption was obtained from questionnaires. Based on the amount of tea consumed per week, 2 groups were divided: drinking tea 3 or more times a week (habitual consumers) and never or rarely drinking tea (less than 3 times a week).
The researchers performed regression analyzes and calculated hazard ratios for atherosclerotic cardiovascular events and death.
Does green tea neutralize “radiation” from your computer?
On the Internet you can find many references to the fact that green tea neutralizes the harm of “radioactive” radiation from a computer or TV.
Over the years, scientific studies have been conducted in which they tried to evaluate whether green tea, for example, neutralizes the negative effects of various radiations: from ultraviolet radiation to the consequences of radiation therapy for cancer patients.
Firstly, the research results turned out, as often happens, contradictory (but it is already clear that tea cannot
); secondly, computers, like any electrical device, emit electromagnetic radiation (EMR), but not radioactive!
There are only a few studies regarding electromagnetic radiation. Yes, small
The work of Chinese scientists reports that green tea can protect against EMR, but they cannot explain how the protective mechanism works, and there are questions about the study: in the experiment, nerve cells treated with polyphenols from a test tube were irradiated. This can hardly be compared with the effect in a living organism.
results
- During a mean follow-up period of 7.3 years, 3683 atherosclerotic cardiovascular events, 1477 deaths due to atherosclerotic cardiovascular causes, and 5479 deaths from any cause occurred.
- Compared with those who never or rarely drank tea, drinking tea 3 or more times per week was associated with a 20% reduction in the risk of atherosclerotic cardiovascular events (hazard ratio, 0.80 (0.75–0.87)), death for atherosclerotic cardiovascular causes by 22% (hazard ratio, 0.78 (0.69–0.88), and all-cause death by 15% (hazard ratio, 0.85 (0.79–0.90).
- Tea drinkers had a 1.4 year longer period of life without atherosclerotic cardiovascular events.
- This association was stronger for study participants who drank tea 3 or more times throughout the observation period.
- Note that the association between tea consumption and cardiovascular events was observed for green tea, but not for black tea.
Does green tea help you lose weight?
“Green tea may speed up your metabolism somewhat and thus affect your body weight, but it’s unlikely that you’ll see a significant difference on the scale from drinking green tea alone,” says David Nieman, MD.
The belief that green tea helps in weight loss has led to a large number of green tea supplements being introduced into the market. A group of Dutch scientists conducted an analysis
all the studies related to weight loss and the use of dietary supplements with green tea, and concluded that, thanks to catechins or a combination of epigallocatechin gallate (a subtype of catechins) and caffeine, it is indeed possible to lose weight, but only by a few hundred grams. Thus, on average, during the periods of observation of volunteers (studies had different durations - from several weeks to several months), Europeans lost about 800 g, and representatives of the Asian race - 1.5 kg. And this despite the fact that the supplements contain higher concentrations of caffeine and catechins than several cups of green tea!
“If we summarize the available research, it turns out that green tea does not have a pronounced effect on body weight,” they summarize
specialists from the National Institutes of Health in the USA (NIH).
Moreover, green tea extract supplements have been shown to cause liver damage. Not because tea is actually bad for the liver, but because everything is good in moderation.
In the study
A group of scientists from the USA and Norway (the results were published in the journal Cancer Prevention Research) women took dietary supplements with green tea extract twice a day. The purpose of the study is to determine the effect of tea on the prevention of breast cancer. After a year of study, a blood test of the subjects showed an increase in the level of liver enzymes, which indicated liver damage.
United States Pharmacopeia (USP) reports
that epigallocatechin gallate (EGCG) supplements may be hepatotoxic at daily intakes of 140 to 1000 mg.
Consumer Reports included
green tea supplements in its list of 15 dietary supplements to avoid. Green tea itself has a much lower concentration of EGCG, so there is no need to worry about it.
The US National Institutes of Health recommends drinking no more than eight cups of tea per day, and no more than six for pregnant and breastfeeding women.
Scientists have described the mechanism of tea's effect on blood pressure
Compounds found in green and black tea help lower blood pressure. This is evidenced by data from a joint study by scientists from the University of California, Irvine and the University of Copenhagen, published in the journal Cellular Physiology and Biochemistry.
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The authors concluded that the catechin-type compounds epicatechin gallate and epigallocatechin-3-gallate, which are found in tea, activate a certain type of ion channel protein called KCNQ5 in the walls of blood vessels, which leads to their relaxation. These compounds were found in the Camellia sinensis plant, the leaves of which form the basis for black and green tea.
The results of the study confirm the data on the antihypertensive properties of tea, and also reveal the molecular mechanism of action of these compounds through the KCNQ5 channel.
According to experts, up to a third of the world's adult population suffers from hypertension. Doctors warn that high blood pressure creates a risk of developing cardiovascular diseases and premature mortality.
The authors suggest that their discovery may serve as the basis for the development of new drugs to lower blood pressure. According to them, a new approach to the treatment of hypertension has enormous potential to improve the health of populations around the world.
In addition, scientists note that KCNQ5 affects certain processes occurring in various parts of the brain. This protein regulates electrical activity and signal transmission between neurons. Disruption of its functioning can lead to epileptic seizures, encephalopathy and developmental disorders. The ability of the compounds to activate KCNQ5, discovered by the study authors, may also help scientists develop drugs to treat brain dysfunctions associated with excitability.
The researchers also described a method that makes activation of the protein more efficient. To do this, you need to heat green tea to 35 degrees Celsius, as a result of which its chemical composition changes. At the same time, it is not necessary to drink the drink hot, the scientists indicated.
“Whether you drink your tea cold or hot, this threshold is reached as the human body temperature is over 36 degrees Celsius. Thus, simply by drinking tea, we activate its beneficial antihypertensive properties,” explains study leader Jeffrey Abbott, professor in the Department of Physiology and Biophysics at the University School of Medicine.
The day before, Turkish doctors named ways to lower blood pressure without medications at home. According to experts, patients should pay attention to nutrition. You need to remove salty foods from your diet, drink water and herbal teas instead of caffeinated drinks, and also eat foods with protein and potassium. Experts named garlic, beets, bananas, pomegranates and hawthorn as some of the most useful foods for fighting blood pressure.
What are the benefits and harms of green tea?
The benefits of green tea have been proven in ancient times. Modern scientists confirm the beneficial properties of tea, but at the same time they also talk about its harm.
USEFUL COMPOSITION
The beneficial qualities of green tea are explained by the content of various substances in it. Tea contains more than 500(!) elements (calcium, magnesium, fluorine, phosphorus, etc.) and almost all groups of vitamins. Also, green tea benefits due to such components as:
CAFFEINE is the main alkaloid of green tea, thanks to which our body receives a surge of strength and a portion of vigor. But green tea does not contain caffeine in its pure form; here it is called theine. Theine has a milder effect than pure caffeine, it activates a person’s mental and physical activity, increases his performance, and lifts his mood.
MINERALS in green tea contribute to the normal functioning of all body systems. Maintaining the correct balance of minerals in the body is the key to strong immunity, healthy hair, nails, teeth, etc.
CAKHETINS are good antioxidants. The most powerful antioxidant of the four main tea cahetins is approximately 35-100 times stronger than vitamins
C and E. Just one cup of green tea a day is enough for this. to provide the body with 10-40 milligrams of antioxidants. Being a strong antioxidant, green tea reduces the likelihood of cancer.
SO WHAT IS THE BENEFIT?
- Green tea is an effective diaphoretic. It is recommended to drink it at elevated temperatures, fever, and various types of inflammation.
- It is especially useful for people suffering from diseases of the kidneys and genitourinary system, and also has a beneficial effect on the gastrointestinal tract and digestion in general.
- Drinking this tea has a positive effect on the functioning of the duodenum, gall bladder, liver and pancreas.
- It can increase attention and improve memory, can invigorate and relieve drowsiness, normalizes metabolism in the body and strengthens the nervous system, helps to get out of depression.
- The beneficial effects of green tea also extend to the cardiovascular system: the beneficial properties of green tea reduce the likelihood of atherosclerosis, improve the elasticity of the arteries, prevent the appearance of cholesterol plaques, increase the strength of capillaries, while the permeability of the walls of blood vessels is reduced and ascorbic acid is better absorbed.
- And he is also an excellent assistant for those who want to lose weight.
WHAT IS THE HARM?
Green tea is harmful to people suffering from nervous exhaustion. Caffeine, which is found in large quantities in green tea, stimulates the nervous system. In this regard, people suffering from nervous exhaustion may experience sleep disturbances and causeless loss of strength.
It is better not to drink green tea before bed at all, as there is a risk of insomnia. Green tea is not recommended for those who suffer from tachycardia, as well as increased excitability.
People with blood pressure problems can feel the harm of green tea. It often lowers blood pressure, so you should not drink it in large quantities if you have hypotension, and drinking green tea for acute hypertension is completely contraindicated.
If you have any chronic disease, then green tea should be drunk with caution, it can cause an exacerbation of the disease and worsen your health. For example, with peptic ulcers, drinking green tea can lead to increased acidity of gastric juice.
If you have gout, it is better not to drink green tea at all, as it is rich in purine bases!
HOW TO DRINK GREEN TEA CORRECTLY
Drinking green tea on an empty stomach is harmful, as it irritates the mucous membrane of even a healthy stomach. And if you drink green tea after eating, then on the contrary, it helps your digestion.
Green tea is much healthier if you drink it throughout the day rather than in the evening or at night. Drinking fresh green tea before bed, having a tonic effect, instead of the expected rest and sweet sleep, will give you a headache and fatigue.
Never alternate green tea with alcoholic drinks! This is a severe blow to your kidneys.
Do not take pills or other medications with green tea - it will remove all chemicals from the body, thereby reducing the effectiveness of the medications.
The harm of green tea may lie in its low-quality varieties. Try to find real, fresh green tea, not the poor version in cheap tea bags.
And remember the golden rule: EVERYTHING IS GOOD IN MODERATION. This also applies to green tea.
Store tea in tin jars with a tight-fitting lid, or better yet, in wooden boxes. Green tea cannot be stored in paper bags: they do not close tightly and allow moisture to pass through.
Head dept. 2nd t/o L.M. Dumpling
