Want to protect yourself against cancer, heart disease, diabetes, tooth decay, and the common cold? How about losing a bit of weight as an added bonus?
Try tea. Research suggests that drinking a daily cup of tea – or rather two or three cups of the beverage – might help ward off chronic diseases including cardiovascular disease, cancers, and diabetes, strengthen the immune system, and act as a weight loss aid.
What is Tea?
True tea comes from the tea plant, Camellia sinensis, an evergreen plant that thrives in warm, wet weather. Several varieties, or subspecies, of Camellia sinensis exist. The most important subspecies are assam, grown in India, and sinensis, grown in China. There are four types of tea: black, oolong, green, or white. All four types of tea can come from the same tea bushes, depending on the way the leaf is processed.
Herbal teas, which may come from a variety of plants, are more correctly called infusions.
What Does the Research Say?
Over and over again, scientific studies have demonstrated that tea has many potential health benefits. Scientists have examined tea’s possible role in preventing and controlling other types of cancer, helping reduce the risk of heart and blood vessel disease, helping control weight and diabetes, preventing cavities, staving off bacterial, viral, and fungal infections, decreasing the risk of Alzheimer’s disease, improving athletic performance, and more. The majority of these studies have shown that tea does indeed have beneficial effects.
For instance, a study published in December 2005 in the Journal of the American Medical Association’s Archives of Internal Medicine suggests that women who drank at least two cups of tea daily had a lower risk of ovarian cancer than non-tea drinkers.
To perform the study, researchers from the Division of Nutritional Epidemiology, The National Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden examined the association between tea consumption and the risk of ovarian cancer in 61,057 women, aged 40 to 76. Women in the study who drank two or more cups of tea per day had a 46 per cent lower risk of ovarian cancer compared with non-drinkers. For each additional cup of tea per day, the women’s risk of ovarian cancer decreased by 18 percent.
In another study, researchers from Brigham and Women’s Hospital and Harvard University found that tea contains a substance that may help the body fight off infection and disease and strengthen the immune system. The substance, L-theanine, helps the immune system in fight infection, bacteria, viruses and fungi. When the researchers tested their theory in humans, they found that people who drank five cups of black tea a day for two to four weeks secreted up to four times more interferon, an important part of the body’s immune defense, than at the beginning of the study. The researchers concluded that drinking black tea provides the body’s immune system with natural resistance to microbial infection.
How Does Tea Help?
Like the fruits and vegetables that health professionals constantly urge everyone to eat, tea contains compounds called antioxidants. In fact, the dried tea leaf is about 40 percent antioxidants.
Antioxidants protect cells in the body by neutralizing “bad” molecules called oxidants (sometimes called free radicals). Oxidants are charged molecules produced when the body burns oxygen for energy. Oxidants damage cell proteins and genetic material by “stealing” electrons. The damaged cells may be vulnerable to cancer, heart disease, and other chronic diseases.
If antioxidant molecules are present, however, they give up an electron to the oxidant molecules before they come in contact with cells, neutralizing the oxidant molecules so they cannot cause damage to cells.
Can Tea Hurt?
Believe it or not, you actually can drink too much tea. Tea contains caffeine. The amount depends on the type of tea, how long it’s steeped, and other factors. On average, though, tea contains about 35 to 40 milligrams of caffeine per cup – less than half the amount in an average 8 oz cup of coffee. Pregnant women, people with heart conditions, and those who wish to avoid caffeine for other reasons should moderate their intake of tea or drink decaffeinated tea (for instructions on how to decaffeinate your own tea, see the next section of this article).
Tea can also interfere with the ability to absorb iron from food. To avoid this problem, some people take Vitamin C with their tea, which can improve iron absorption. A better solution (in those in whom iron deficiency may be a problem) is simply to drink your tea between meals.
Low-grade teas (such as the brick teas drunk in parts of the Himalayas) and powdered iced tea mixes can be high in fluoride. Because of this high fluoride content, consuming large quantities of low-grade or iced teas can lead to brittle bones.
The Perfect Pot of Tea
How can you get the most out of your tea? Researchers suggest drinking three cups a day at different times throughout the day. Spreading your tea drinking out over the day allows you to absorb the largest amount of polyphenols and other healthful compounds.
Avoid decaffeinated, bottled ready-to-drink teas, and instant teas, which all have fewer polyphenols than freshly steeped tea made from tea leaves.
* You can decaffeinate your own tea without losing its beneficial effects. Pour boiling water over a teabag, wait 20 to 40 seconds, then discard the water. Then pour a second cup of hot water over the teabag and allow it to steep for five minutes. Because caffeine dissolves easily in water, you’ll throw out most of the caffeine with the first cup of water.
* If you prefer your tea iced, start with tea bags, not iced tea mix.
The beneficial effects of tea also depend on how you brew it. Here’s how:
1. Always start with fresh, cold water. For best taste, use filtered or spring water. If you’re using tap water, start with cold water. This reduces the risk of picking up heavy metals from water pipes, especially in homes with older plumbing systems.
2. For each cup, place one teabag, or one teaspoon of loose tea, in the cup or pot.
3. Bring the water to a rolling boil (203 degrees Fahrenheit).
4. For black or oolong tea, pour the boiling water over the dried tea immediately after it boils.
5. For green and white tea, wait 2 minutes after the water has boiled before pouring the hot water in the pot. Green and should steep at slightly lower temperatures (158 to 203 degrees Fahrenheit).
6. Steep the tea according to its type:
a. Step black tea for five minutes to get the full benefits of the catechins. About 85 percent of catechins are released within five minutes. Steeping for longer than five
b. Steep green or white tea for two to four minutes.
c. Steep oolong tea for up to six minutes.
7. Enjoy! If you prefer, add milk and sugar. Adding milk to your tea provides nutrients including calcium, protein, and Vitamin D.
Related Resources
Tea Association of Canada
http://www.tea.ca
Tea Association of the United States
http://www.teausa.com
United Kingdom Tea Council
http://www.tea.co.uk
[Source: E Health MD]
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