The leaf and bud of the camellia plant are the basis of both green and black tea. Unlike black tea, which is fermented, green tea is steamed dry immediately after harvesting, which leaves it with larger amounts of polyphenols. It’s most effective polyphenol is epigallocatechin gallate (EGCG). Most of the benefits of green tea consumption appear to be preventive in nature. It is not known exactly how much you need to reap the potential benefits, but four cups a day or more may be required for benefit. Oolong tea has been “fermented” (or more accurately, “oxidized”) more than green tea but less than black tea. Oolong tea is sometimes referred to as “semi-fermented”.
Decaffeinated green tea does have the same amount of EGCG as regular green tea. Check your local health food store for decaffeinated green tea capsules. Depending on the brand, one capsule can supply as much EGCG as four cups of tea.
Bottled tea and instant tea have few antioxidants, research shows. Herbal teas do not have the same health properties as real tea (Camellia sinensis). Tea with caffeine has slightly more antioxidant activity. Steep tea leaves or bags in hot water 3 to 5 minutes to thoroughly release antioxidants. Adding milk to tea does not block absorption of antioxidants, new Dutch research finds.
Green / Oolong / BlackTea (Camellia sinensis) can help with the following
Anemia (Iron deficiency)
Tea “chelates” iron, removing it from the body which may cause iron deficiency anemia in young people.
Sun Damage/Overexposure
Drinking four or more cups of green tea each day may help stave off skin cancer. This substance could be similarly effective if incorporated into skin care creams, but the quantity and consistency of EGCG (active compound found in green tea) should be questioned.
HPV (Human Papilloma Virus)
Genital and anal warts are caused by human papillomavirus (HPV), and there has been a lack of effective, well tolerated treatments.
Researchers assigned over 500 adults with 30 warts to either sinecatechins (a green tea extract) ointment or a placebo. In the sinecatechins groups, warts cleared completely in roughly 57% of patients, compared to just 34% of subjects in the control group. [Obstetrics and Gynecology, 111(6):pp.1371-1379, June 2008]
Chronic Inflammation
Researchers at Case Western Reserve University gave arthritis-prone mice either green tea or water. The human equivalent of 4 cups of green tea daily halved the mice’s risk of developing arthritis. Also intriguing: TF-2, the anti-cancer compound in black tea, suppresses the Cox-2 enzyme that triggers inflammation, says research at Rutgers. That’s the same way the drugs Vioxx and Celebrex work.
Depression
Previous studies have reported that green tea exerts a variety of beneficial effects on stress and inflammation, Kaijun Niu, from the Tohoku University Graduate School of Biomedical Engineering (Japan), and colleagues investigated the relationship between green tea consumption and depressive symptoms. Studying a group of 1,058 community living elderly Japanese individuals, ages 70 and over, the researchers surveyed green tea consumption and evaluated depressive symptoms via the Geriatric Depression Scale. They found that those study subjects who drank four or more cups of green tea daily were 44% less likely to have symptoms of depression (as compared to subjects who drank one or less cups). The team speculates that the amino acid theanine, present in green tea, which has a calming effect on the brain, may contribute to the beneficial effect seen on depression in this study.
Problem Caused By Being Overweight
70 moderately obese patients received 2 capsules of a green tea extract morning and midday for 12 weeks. This extract contained 27mg of epigallocatechin gallate (EGCG) and 150mg per day of caffeine. Mean body weight and waist circumference decreased by over 4%. The effect on thermogenesis (calorie burning) was greater than that which would have been caused by equivalent amounts of caffeine. This effect was not accompanied by an increased heart rate as seen with the sympathomimetic drugs used to treat obesity! Green tea (extract AR25) is an effective treatment for obesity, possibly due to its ability to inhibit lipases and stimulate thermogenesis. [Phytomedicine 2002;9: pp.3-8]
In a Swiss study, a daily dose of 270mg EGCG (the amount in 2 to 3 cups of green tea) caused men to burn 4% more energy – about 80 extra calories a day. Green tea did not increase heart rate, and the calorie burning was not due to caffeine.
Osteoporosis / Risk
Drinking regular tea was associated with a small improvement in bone mineral density, but was not associated with the risk of hip or forearm/wrist fractures. This study was done in the United States using 4,979 women over 50 years old who were followed for an average of 4years. [Am J Epidemiol 2003;158(8): pp.772-81]
Antioxidant Need/Oxidative Stress w/o Supplements
Studies of humans and animals show that the antioxidants in black and green teas are highly beneficial to our health, says 82-year-old John Weisburger, PhD, senior researcher at the Institute for Cancer Prevention in Valhalla, N.Y.
“I’ve published more than 500 papers, including a . . . Lot on tea,” says Weisburger, who drinks 10 cups daily. “I was the first American researcher to show that tea modifies the metabolism to detoxify harmful chemicals.”
Diabetes Type II
Epigallocatechin gallate (EGCG), a compound found in tea, may reduce the association between high-fructose corn syrup (HFCS) and diabetes, according to researchers from Rutgers University. Stopping the intake of HFCS would be best, but consuming tea does seem to provide a protective effect, if one continues to use HFCS. [Beverage Daily August 28, 2007]
Increased Risk of Diabetes ll
Epigallocatechin gallate (EGCG), a compound found in tea, may reduce the association between high-fructose corn syrup (HFCS) and diabetes, according to researchers from Rutgers University. Stopping the intake of HFCS would be best, but consuming tea does seem to provide a protective effect, if one continues to use HFCS. [Beverage Daily August 28, 2007]
Hepatitis
Green tea can decrease inflammation. 2 to 3 cups per day.
Increased Risk of Ovarian Cancer
Drinking tea can cut the risk of developing ovarian cancer by almost half, according to a major study by scientists in Sweden. Just two cups of tea a day was found to reduce the chance of the disease by 46%, the researchers found, after studying the records of more than 61,000 women over a period of about 15 years.
Laboratory research has found that black and green tea can protect against a range of cancers, but there have been few studies to look at the real incidence of cancers among drinkers and non-drinkers of the brew, until now. [Archives of Internal Medicine, Dec. 12, 2005]
Increased Risk of Prostate Cancer
A study has revealed that the once highly praised antioxidants found in red wine, grapes and peanuts were not as effective cancer preventatives as green and black tea, in slowing down the progression of prostate cancer. Participants of the study involved 20 men who had prostate cancer and were pending prostate removal surgery. Each of the men were required to drink five cups of black tea, green tea or soda each day for five days prior to their scheduled surgeries.
The goal of the study was to determine if polyphenols, a substance found in tea, might contribute to slowing down the cell growth of the prostate cancer. One component of the study involved cutting out a piece of each man’s prostate for examination. The study revealed a decrease in the growth rate of the cancer cells in the men who had consumed the black or green tea, however there was no change in the men who drank soda. [Free Radical Biology & Medicine April 2004;36(7): pp.829-37]
Increased Risk of Esophageal Cancer
Regular and substantial consumption of green tea may provide protective effect against this type of cancer. Green tea reduced the risk of esophageal cancer in women by 50%, and in non-smoking men and women by 60% [J Natl Cancer Inst Jun 1, 1994; 86(11): pp.855-8]. Risk decreased as tea consumption increased.
Increased Risk of Coronary Disease / Heart Attack
In a large 10-year study in the Netherlands, men who consumed the amount of antioxidants called “catechins” found in three cups of black tea were 50% less likely to die of ischemic heart disease, caused by narrowed clogged arteries, than were men who consumed only the catechins in half a cup of tea. In another recent test, Joseph Vita, M.D., of the Boston University School of Medicine, had heart patients drink either plain water or four cups of black tea daily. In a month, impaired blood vessel functioning (a risk factor for heart attack and strokes) improved about 50% in the tea drinkers.
Cancer / Risk - General Measures
Green tea can delay or prevent the occurrence of some cancers, but typically must be consumed in large quantities (up to 10 cups or more) daily to achieve this effect. Extracts taken in pill form may be more convenient. There are also teas available with added SGS, which does have an independent cancer preventive action.
Increased Risk of Bladder Cancer
Regular and substantial consumption of green tea may provide protective effect against this type of cancer.
Increased Risk of Hypertension
Regular and substantial consumption of green tea may provide protective effect against hypertension.
Increased Risk of Stomach Cancer
A study of over 600 Chinese men and women showed that green tea drinkers had a 48% lower risk of stomach cancer than non-drinkers. [Int J Canc May, 2001;92: pp.600-604] This effect may have been from reduced stomach inflammation.
Increased Risk of Colon Cancer
Regular and substantial consumption of green tea may provide protective effect against this type of cancer.
Increased Risk of Pancreatic Cancer
Regular and substantial consumption of green tea may provide protective effect against this type of cancer.
Eczema
In one study, a 10gm bag of Oolong tea was soaked in 1 liter of boiling water, 1/3 of which was consumed after each meal of the day. Reduced itching and inflammation was reported and 54% showed a good or better response after 6 months of use.[Archives of Dermatology (2001;137: pp. 42-3]
Male Hair Loss
Of interest to those with androgenetic alopecia is evidence that green tea can influence serum concentrations of hormones. High intake of green tea has been associated with higher levels of sex hormone binding globulin (SHBG) and lowered levels of serum estradiol (estrogen) concentration in women. Increased SHBG may be of help in reducing the effects of androgenetic alopecia (pattern baldness).
Prostate Cancer
A study has revealed that the once highly praised antioxidants found in red wine, grapes and peanuts were not as effective cancer preventatives as green and black tea, in slowing down the progression of prostate cancer. Participants of the study involved 20 men who had prostate cancer and were pending prostate removal surgery. Each of the men were required to drink five cups of black tea, green tea or soda each day for five days prior to their scheduled surgeries.
The goal of the study was to determine if polyphenols, a substance found in tea, might contribute to slowing down the cell growth of the prostate cancer. One component of the study involved cutting out a piece of each man’s prostate for examination. The study revealed a decrease in the growth rate of the cancer cells in the men who had consumed the black or green tea, however there was no change in the men who drank soda. [Free Radical Biology & Medicine April 2004;36(7): pp.829-37]
Rectal Cancer
Rutgers University researchers showed that a compound in black tea called TF-2 caused colorectal cancer cells to “commit suicide”; normal cells were unaffected. “The effect is quite dramatic,” said Rutgers professor Kuang Yu Chen, who speculates that the chemical might one day be made into an anti-cancer drug.
Key
| May do some good |
| Likely to help |
| Highly recommended |
| May have adverse consequences |
Glossary
Antioxidant
A chemical compound that slows or prevents oxygen from reacting with other compounds. Some antioxidants have been shown to have cancer-protecting potential because they neutralize free radicals. Examples include vitamins C and E, alpha lipoic acid, beta carotene, the minerals selenium, zinc, and germanium, superoxide dismutase (SOD), coenzyme Q10, catalase, and some amino acids, like cystiene. Other nutrient sources include grape seed extract, curcumin, gingko, green tea, olive leaf, policosanol and pycnogenol.
Herbs
Herbs may be used as dried extracts (capsules, powders, teas), glycerites (glycerine extracts), or tinctures (alcohol extracts). Unless otherwise indicated, teas should be made with one teaspoon herb per cup of hot water. Steep covered 5 to 10 minutes for leaf or flowers, and 10 to 20 minutes for roots. Tinctures may be used singly or in combination as noted. The high doses of single herbs suggested may be best taken as dried extracts (in capsules), although tinctures (60 drops four times per day) and teas (4 to 6 cups per day) may also be used.