Tea has as much health-promoting properties as wine. You just need to learn how to brew it.
There is hardly any more tea enthusiast than Dr. John Weisburger. A retired professor at the US Institute for Cancer Prevention drinks up to 10 cups a day. However, it is not the taste values that she values the most. He is a fan of tea because of its health-promoting properties. – The substances contained in the infusion prevent strokes, heart attacks, cancer and tooth decay, and also slow down the aging process – says Dr. Weisburger. And he knows what he is saying. First, he conducted a lot of research into the effects of tea. And secondly, he has been living for 90 years, which – as he claims – is due to this drink. The health benefits of tea became famous in the 90s. Then scientists showed that it contains large amounts of polyphenols. These compounds have extremely strong antioxidant properties, i.e. they inhibit free radicals. Therefore, polyphenols protect against the development of cardiovascular diseases and cancer and prevent rapid aging. It has been calculated that one cup of strong tea contains as many as in five glasses of orange juice. “In this respect, only red wine can match tea,” says Gerald Weissmann of the New York University School of Medicine.
The strength of its activities was proven by a large Dutch study published a year ago. They covered as many as 37 people. The researchers, led by Dr. Yvonne T. van der Schouw from the University Medical Center in Utrecht, monitored the health of the participants for 13 years. On this basis, they found that drinking three to six cups of tea a day reduced the risk of dying from heart disease by as much as 45 percent. compared to those who drink less than one cup a day.
A weapon against free radicals
– All its varieties are good for health: black, green, red and white. However, depending on the color, which indicates the degree and type of processing, the content of valuable compounds is different – says Dr. Wojciech Kolanowski, food and nutrition technologist from the Warsaw University of Life Sciences.
The most and the strongest antioxidants are found in green tea. That is why it is recommended especially in the prevention or fight against cancer, atherosclerosis and allergies. A team of Dr. I-Hsin Lin from Chung Shan Medical University in Taichung, Taiwan, published a paper a few weeks ago proving that the drink protects against lung cancer. People who do not drink green tea are five times more likely to develop this cancer than those who consume at least one cup of green tea a day.
The results were even more interesting when scientists looked only at smokers. It found that tea addicts who weren’t at risk of cancer were 12 times more likely than tea gourmets who smoked. One of the most powerful antioxidants in green tea is epigallocatechin gallate (EGCG). In terms of the power of destroying free radicals, it has a power as much as 20 times greater than vitamin C, one of the strongest antioxidants. In June this year, it was finally possible to discover what the secret of its operation was. Well, EGCG increases the number of cells in the immune system called regulatory T lymphocytes, determined the team of Dr. Emily Ho of the US Linus Pauling Institute. In this way, it inhibits the inflammation process, increases the body’s immunity and, as a result, protects against the development of diseases. The researcher hopes that she will be able to obtain an extract containing EGCG, helpful in the treatment of, among others autoimmune diseases in which the body attacks and destroys its own cells.
The remaining varieties of tea no longer have such a strong antioxidant effect as green tea, but contain tannins with astringent properties and soothing irritation of the mucosa. For this reason, especially drinking black tea is recommended during diarrhea and other gastric ailments. The effectiveness of this solution has been confirmed by research by scientists from the Unilever laboratory in Vlaardingen, Netherlands. They were carried out on piglets, which, like humans, contracted a gastrointestinal infection caused by the bacterium Escherichia coli. Sick animals were given orally black tea extract, which by 20 percent. reduced the severity of diarrhea. Tannins also prevent the absorption of heavy metals such as lead. And if any amount of these harmful substances penetrates the body, the compounds contained in tea have a protective effect on organs. This has been shown by experiments on rats. Scientists from the University of Alexandria in Egypt and the University of Kashmir in India watered the rodents with lead water. The effect was, inter alia, a reduction in the ability of the animals’ liver to regenerate. The organ was only in better condition in those rats given concurrently with the tea extract. This is important information that the liver is one of the organs most at risk from lead poisoning.
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Black tea can be used to treat diabetes. These surprising conclusions come from a study conducted at the Chinese Nankai University in Tianjin. The polysaccharides contained in it delay the absorption of glucose. In this way, they prevent sudden states of high blood sugar levels that can damage internal organs. Their formation occurs due to a defect in the production or action of insulin, which is the basis for the development of diabetes. The compounds in black tea – theaflavin and thearubigin – mimic the action of this hormone. As a result, they help convert glucose into energy and prevent sugar spikes, as demonstrated by scientists from the University of Dundee in Scotland. However, for tea to have a health-promoting effect, you need to drink it at least an hour after eating. This is especially true for people suffering from anemia. – The tannins contained in tea can be up to 70 percent. weaken the absorption of iron from food – says Dr. Kolanowski. Researchers at the University of Pennsylvania have determined how this process works. They found that the tea compounds bind to iron in the cells of the intestine to form molecules that cannot be transferred any further. Instead of entering the bloodstream, they are excreted from the body, which can lead to anemia.
It is more harmful than good to drink too hot tea at a temperature above 70 degrees C. The result may be the development of esophageal cancer, it was established by studying the inhabitants of the Iranian Golestan province, where the incidence rate of this cancer is the highest in the world. In addition, if you want to enjoy the beneficial effects of tea, you need to store it in an airtight container. As a result, valuable compounds will not be degraded, for example, under the influence of moisture. – If the tea is not packed tightly at the place of collection, it will partially lose its pro-health values - says Paweł Dudziak, knowledge management manager of the Dilmah brand.
And one more thing: the health-promoting properties of the substances contained in the aromatic leaves decrease if you prepare a drink with the addition of milk or sugar. And you absolutely shouldn’t brew tea with lemon. Due to the acidified environment, the aluminum present in the leaves – the tea bush has the property of accumulating it – will be a component of the infusion. This was proved by, among others, Polish scientists from the Military University of Technology. Excess aluminum accumulates in the brain tissue, which can result in memory impairment and even dementia. So if we want tea with lemon, put it in the cup after straining the infusion.
And then just enjoy the taste. The rest will be taken care of by the polyphenols.
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