The benefits of tea

Published 8:00 am Tuesday, March 22, 2022

This week’s “unsung hero” of nutrition is actually a drink. Tea is the most popular drink worldwide, but in the United States, it ranks behind coffee, soft drinks, milk and fruit juice. Medical researchers are finding potential healing properties in this ancient beverage (the history of tea dates back to ancient China, almost 5,000 years ago). The word tea comes from the Chinese “te”, later the Malay and Mandarin “cha,” then “tea.” The most popular teas are black, red, white and green. These are produced from the leaves, buds and stalks of the camellia sinensis plant. Black, red and white teas are dried, crushed, then fermented. Black tea is the most fermented tea. The length of fermentation determines whether the tea will be black or red. White tea is processed the least. To manufacture tea, camellia sinensis leaves are simply picked, dried, then heated to preserve freshness. Green tea is merely steamed quickly before packaging, and therefore is the least processed. 

                   

Leaves of the camellia sinensis plant contain compounds called polyphenols. These polyphenols act as antioxidants that protect the body’s cells from free radical damage, help prevent premature blood clotting and assist in boosting the immune system. Some researchers believe these polyphenols can also lower cholesterol levels, neutralize enzymes that aid in the growth of tumors and deactivate cancer promoters, which are chemicals or substances that promote expansion of initiated cancer cells. 

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Since green tea is unfermented, it retains more polyphenols than either black, red or white tea. Apart from polyphenols, tea contains theanine, an amino acid unique to tea. Theanine, along with vitamins and minerals (vitamins C, D, K and riboflavin B2, and calcium, iron, zinc, sodium and nickel) found in tea,help reduce high blood pressure, premature aging, improve digestive function, and aid in fighting viral and bacterial infections. Tea also contains fluoride for strong teeth. When considering caffeine, tea leaves do have higher concentrations than coffee, by weight, but more coffee than tea is required to make a cup. 

                    

Tea also contains small amounts of the “caffeine related” compounds theophylline and theobromine. These substances, along with caffeine, are known as xanthenes. All three produce similar actions within the body, but differ in their intensity. Caffeine is absorbed rapidly, and appears in all body tissues within about five minutes of ingestion. It reaches its peak in about 30 minutes. Mild doses of caffeine (85-250 milligrams – the equivalent to one to three cups of coffee) help suppress fatigue and improve alertness, but higher doses may produce nervousness, restlessness and insomnia. Xanthenes increase blood flow to the heart, but if used in excess, can in some instances trigger irregularities in heartbeat. However, in contrast to the dilating effect to other blood vessels, xanthenes constrict blood vessels in the brain. For this reason, caffeine may relieve some headaches, and is often a component of prescription and non-prescription headache medications. 

                     

With the focus of so many folks today on natural, caffeine-free alternatives to coffee and tea, “herbal teas” have become especially popular. Actually, herbal teas aren’t true “teas” in the actual sense, in that  they are not produced from the camellia sinensis plant, but rather are brewed flowers, leaves, seeds, bark and roots of certain plants, or combinations of plants. Popular herbal tea blends include ginger, cinnamon, mint, lemon, orange and apple. While it’s true many herbs have been approved by the FDA (Food and Drug Administration), it is equally true that many have not been tested for safety for use as teas. For example, one pinch of nutmeg, when added to eggnog, produces no harmful effects, but when brewed into tea can cause dizziness, rapid pulse and disturbed vision. In 1975, the FDA evaluated 171 herbs commonly used in herbal teas. Of these, 91 were determined to be safe, 53 were classified as of undefined safety and 27 were placed in the unsafe category. Also remember, just because it’s “herbal” or “all natural”, doesn’t mean it’s safe. Mandrake, hemlock, belladonna, curare, lobelia, root of pokeweed, mistletoe, wormwood and foxglove are all herbal, but highly toxic.

                      

To enjoy herbal teas safely, I do recommend the following:

  • Buy only tea bags (not loose tea) from well known manufacturers. 
  • Use new varieties sparingly. If there are no adverse effects, use more next time. 
  • Read the ingredient label carefully. The names of certain teas don’t really tell you all that’s in them. 
  • If you take medications, over the counter or prescription, check with your physician or pharmacist before indulging in herbal tea. 
  • Never gather leaves, buds or other plant parts to make your own herbal tea, as these can be deadly. Don’t drink more than 2-3 cups of herbal tea a day, since its long-term effects aren’t really known. 
  • If you are pregnant, always check with your doctor before starting any herbal tea. 

 

David Crocker is a nutritionist and master personal trainer. Questions? Email David at dwcrocker77@gmail.com.