The tea is harmful: 6 unexpected findings of scientists
Educational Program Health / / December 19, 2019
The benefits of tea there is little doubt that billions of Asians who use this hot drink for thousands of years, can not be wrong. Tea perfectly quenches thirst and invigorates, reduces cholesterol levels and normalizes the cardiovascular system, slows aging and even making smarter.
However, an abundance of advantages does not exclude the minuses.
1. Hot tea can cause bleeding
British audiologist and the plastic surgeon Henry Sharpe (Henry Sharpe) considersTea could be bad for your healthThat the habit of drinking tea piping hot can badly affect the nasopharynx vessels. Steam from cup causes them to expand and often provokes nosebleeds.
In addition, there is a versionTea drinking habits and oesophageal cancer in a high risk area in northern Iran: population based case-control studyThat hot tea may increase the risk of developing esophageal cancer. Fortunately, it did not all agree.
In any case, the optimal temperature of the beverage considered to 50-60 ° C. To achieve the ideal, by drinking cup with freshly enough to stand 5-7 minutes at room temperature.
2. Too strong tea destroys teeth and bones
The New England Journal of Medicine published a few stories of patients who have suffered from the habit of drinking too much strong drink. Thus, the remarkable case of a 47-year-old womanSkeletal Fluorosis Due to Excessive Tea Drinking, For 17 years on a daily basis are treated to tea, brewed from 100-150 bags. In a relatively short period of time it has lost almost all his teeth and got excessive bone fragility. These are symptoms of skeletal fluorosisfluorosis. It is caused by the accumulation of fluoride in bones coming including the strong tea.
It is clear that much strong tea not everyone will join in yourself, but keep in mind as it is worth. Nutritionists recommend eating no more than 4-5 cups a day.
3. Tea may contain heavy metals
In 2013, the Canadian Journal of Toxicology published a studyThe Benefits and Risks of Consuming Brewed Tea a large number of tea bags of samples from different regions of the planet.
TOXICOLOGY found in samples of heavy metals, in particular lead, aluminum, arsenic and cadmium. It is assumed that metals get into the tea leaves from contaminated soils: often plantations are located, for example, next to the environmentally unfriendly coal-fired power plants.
The metal concentration in the beverage depends upon the infusion time. If the bag is in the water 15-17 minutes, the level of toxic substances rises to unsafe (e.g., some samples the aluminum concentration was up to 11 449 g / l at the admissible maximum daily in 7000 ug / L).
Scientists have concluded that the longer the tea is brewed, the more any muck is washed out of the leaves in water. Therefore, it is not necessary to insist drink more than 3 minutes.
Another option - to give preference to white tea. Its leaves are disrupted quite young, which means they do not have time to accumulate a critical dose of heavy metals.
4. Sometimes tea is harmful to the liver
Herbal teas often accumulate a pyrrolizidine alkaloid - toxins produced by some species of flowering plants. For example, a harmless at first glance, the mother-and-stepmother.
These toxins adversely affect the body as a whole, but their main target is the liverToxicity and metabolism of pyrrolizidine alkaloids. In 2015, the American Journal of Food Chemistry published a studyPyrrolizidine alkaloids in herbal teas for infants, pregnant or lactating women 44 samples of herbal teas, intended for babies, pregnant and lactating women. Scientists have found pyrrolizidine alkaloid in 86% of samples.
In principle, the dose of toxin that actually get from tea (with a moderate its use, of course), is practically safe for an adult. With babies, as well as pregnant and nursing women the situation is different. Due to the low body weight baby and the more unborn baby is more vulnerable to toxins that come to him from his mother.
5. Drinking tea after eating can lead to a shortage of iron
Research conducted by the University of California in 2011, provedIron deficiency anemia due to excessive green tea drinking: Tea "binds" to proceed with food iron, significantly impairing its absorption by the body. If you regularly drink tea after a meal, it can be drunk before the glandular deficiency, which is fraught with unpleasant consequences: deterioration of the skin, hair, slackness to iron deficiency anemia, which have to deal with doctor.
Therefore, doctors recommendEffect of tea and other dietary factors on iron absorption do not drink a drink for breakfast, lunch or dinner. Before tea must pass at least 20 minutes.
6. Tea provokes insomnia
Blame caffeine and aromatic substances, for which we are, in fact, tea and love. The invigorating effect of the drink has a physiological basis: pulse rate, blood flow is accelerated, the adrenal glands secrete more adrenalineCaffeine affect blood pressure, Central nervous system and the brain gets excited... In the morning or in the middle of a working day tea - just a godsend!
But in the evening tea excitement could kill you all sleep. If you really really want a cup of tea at night, it is better to restrict herbal drinks, the caffeine content of which is reduced as compared with the black and especially green tea.
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