Chilly winter weather, blustery winds and fewer hours of daylight send many of us seeking warming comfort foods. Afternoon tea with a friend or relation helps us pass long winter afternoons and brightens a dreary day. As you sip and share stories with friends you may be unaware of the health promoting properties of tea. Protection against Parkinson’s disease, high blood pressure, vascular disease, prostate cancer, ovarian cancer and heart attack and stroke are, in all probability, far from your mind. Yet, according to many studies conducted over the past decade, tea has profound health benefits.
Where Does Tea Come From?
Tea consumption originated in China and dates back over two thousand years. Tea spread to Europe in the 14th century and was imported from Europe to the Americas. Today tea is second only to water as the most widely consumed beverage in the world. Tea is made up from the leaf and bud of the plant Camellia Sinensis, which is indigenous to China and India.
The Color Of Tea
There are many different types of teas – black, green, white, Pouchong or Oolong tea. All are from the Camellia Sinensis plant. Processing differences of leaves and buds result in different types of tea. When the leaves of the tea plant are dried they undergo enzymatic oxidation. Tea producers call this process “fermentation”, a term which, when applied to tea, is actually a misnomer. Fermentation is a term used in biology or food production and means the conversion of a carbohydrate into an acid or alcohol. Tea fermentation, however, refers to how long the leaves are allowed to dry. As the leaves dry they oxidize and become darker. The aroma and flavor becomes stronger. More highly fermented teas tend to have higher amounts of caffeine.
Non-fermented or lightly fermented teas include green tea and white tea. White tea includes buds as well as leaves and is lower in caffeine. Semi-fermented teas include Pouchong (Jasmine tea is Pouchong flavored with Jasmine flowers), and Oolong. Black tea is fully fermented and has a brown or dark red color. A cup of green tea contains about 10 to 20 mg of caffeine. A cup of coffee has between 80 to 120 mg of caffeine.
Health Benefits of Green Tea
Green tea is the most extensively studied. Green tea contains antioxidants called polyphenols, caffeine and a caffeine like substance called theophylline. The main polyphenol identified with health benefits is a catechin called epigallocatechin – 3 – gallate (EGCG). Green tea also contains gallic acid, and flavonols kaempferol, myricetin and quercetin. It is important to note two factors in assessing the benefits of tea. The first is that most of the studies look back at populations and draw an association in terms of risk reduction. We can only identify a trend, not state for sure that tea prevents a particular disease. The second consideration is that in some of the positive studies subjects drank a lot of tea – 6 cups a day or more. Most people don’t drink that much and would have a hard time with the caffeine levels.
Green tea consumption is associated in some studies with a lowered risk of breast cancer, prostate cancer, and ovarian cancer. Risk reduction in ovarian cancer was seen in women who drank 2 or more cups per day. For breast cancer, recurrence was reduced in women who drank 3 or more cups per day.
Green tea polyphenols also have antibacterial, anti-fungal and antiviral activity. Green tea has been shown to have activity against salmonella and clostridium bacteria, which cause severe GI infections. It has also shown to be active against Helicobacter Pylori, and infection associated with gastric ulcers. Green tea also has some activity against Candida fungus.
Green tea consumption is also associated with increased bone mineral density and has been identified as a factor that may prevent the risk of hip fractures.
Green tea may also protect against arteriosclerosis and has been shown to improve blood flow in the brachial artery, which is an important indicator for healthy blood vessels. It also has been shown to improve memory and cognitive function and may reduce the risk of Parkinson’s disease.
Green tea has been shown to be active against the virus that causes genital warts. An extract of green tea has been formulated into an ointment called Veregen, which is approved by the FDA for treating genital warts.
Health Benefits of Fermented and Semi-Fermented Teas
As tealeaves are fermented to produce either Oolong or Black Teas, the polyphenols become oxidized, so there is less ECGC and other catechins associated with anti-cancer activity. Black tea has anti-oxidants called theaflavins, which may be beneficial for preventing arteriosclerosis and cardiovascular disease. Black tea may improve vessel dilation in people with heart disease and may mildly lower bad cholesterol.
Fermented teas also reduce the risk of ovarian cancer. Woman who consume two or more cups of tea - black, green or Oolong – have a 46% lower risk of ovarian cancer compared to women who drink no tea.
People who drink tea of any type seem to have a lower risk of Parkinson’s disease. Black and Oolong tea, like green tea, have a protective effect against osteoporosis.
Precautions Regarding Tea Consumption
Both caffeine and theophylline are stimulants that may increase heart rate and cause nervousness. Some people are extremely sensitive to stimulants in tea and may respond with irregular heartbeats. If you experience palpitations, you may want to switch to decaffeinated teas or avoid tea. Pregnant and breast feeding women should limit tea intake to 1 to 2 cups per day, as it can cause an increase in heart rate. Some teas, depending on where they are grown and processed, contain aluminum and fluoride, which may accumulate in excessive tea drinking. Picking a quality brand is important. Tea consumption with meals will inhibit iron absorption. If you have iron deficiency anemia either avoid tea or take it apart from meals.
Decaffeinated tea looses some of the valuable, cancer preventing polyphenols. The best process, which results in only a small loss of polyphenols, is called effervescence. Look on the label for this type of decaffeination process.
Teatime is an opportunity to slow down, warm our bodies, enjoy our relationships, and nurture our health with remarkable functional food. Best wishes for a peaceful holiday season.
These statements have not been evaluated by the Food and Drug Administration. They are not intended to diagnose, cure or prevent any disease. They are for information purposes only.
Beneficial Effects of Green Tea – A Review. Cabrera C., et. al. Journal of the Am. College of Nutrition. Vol. 25, No. 2 79-99 (2006)
Debbie Edson is a registered pharmacist, with a background in hospital and community practice. She is proprietor of Healthy Morning, LLC. Her passion is educating people about evidence based natural healing. She is a recent contributor to the best selling book, Prescription For Nutritional Healing, 4th Ed. Debbie lives in Massachusetts with her husband, David. She has one child, Laura Novak, who is a photographer in Wilmington, Delaware.