By Shirley Vanderbilt
Originally published in Massage & Bodywork magazine, February/March 2001.
In an age when ancient remedies are increasingly emerging as solutions to our modern medical questions, researchers are finding a blend of simplicity and complexity in their work. So is the case with green tea. For thousands of years, the Chinese have known the power of its healing properties, incorporating its use in their traditional tea ceremonies. Now green tea has found its way into the heart of Western medicine as an anti-inflammatory and antioxidant agent capable of blocking the carcinogenic effects of free radicals in the human body. The process of administering this miracle elixir is quite simple, but discovering the reasons for its effectiveness has drawn researchers deep into their laboratories to decipher complex chemical compositions with equally complex scientific names. One such scientist is Santosh K. Katiyar, Ph.D., of the Department of Dermatology at Case Western Reserve University in Cleveland, Ohio. Katiyar has figured prominently in investigating the relationship between green tea and skin. In a recent article, he stated that green tea has an “antioxidant activity superior to that of any other naturally occurring antioxidant known.”1 Through his work and that of others in this highly specialized field, we have come to learn more about the mysterious properties of this very basic, unassuming beverage.
What is Green Tea?
Green, black and oolong tea leaves all come from the same plant, Camellia sinensis, a large evergreen shrub native to Eastern Asia. But it’s the difference in processing that defines their color, aroma and level of health benefits. Basically, black tea is fermented and oolong tea is partially fermented, causing oxidation of the original chemical components. Green tea is steamed and dried at an elevated temperature to avoid oxygenation and change in the structure of polyphenols (the antioxidant agents). Because it is not fermented, the chemical properties of green tea are very similar to that of the original, fresh picked leaf.2
A Brief Look at Chemistry
Green tea contains polyphenols, natural compounds that give the tea its flavor, color and antioxidant potential. These polyphenols account for approximately 30 percent of the weight of processed green tea and 78 percent of its antioxidant constitution. Some of these polyphenols are flavanols, more commonly called catechins. The four major catechins in green tea are epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and epigallocatechin gallate (EGCG). Of these, EGCG has emerged as the most potent in its ability to fight carcinogenic and inflammatory responses.3
Although researchers are still investigating the mechanisms involved,4 it is known that these catechins reduce free radicals and prevent their formation. Ken Cohen, a Qigong master and avid proponent of green tea, gives us a metaphor for the destructive force of free radicals in his book, The Way of Qigong. He writes, “Antioxidants destroy or deactivate free-roaming and highly reactive oxygen molecules. These ‘free radicals’ essentially do to our bodies what oxygen does to household oils and fats; they turn us rancid and stale.”5 By modulating these errant biochemicals, catechins have a significant affect on reducing inflammatory responses and tumor promoters.
The antioxidant effect of green tea, estimated to be 200 times that of vitamin E, benefits almost every body system, according to Mitscher and Dolby in The Green Tea Book.6 It “lowers cholesterol and blood pressure, which reduces the risk of heart attack and stroke; prevents cancer from starting and spreading; boosts immunity and fights infection; and even helps prevent dental cavities.”7
Specific to the Skin
“Sun, gravity, free-radical damage and a poor diet take their toll on healthy, youthful-looking skin,” say Mitscher and Dolby. They note that change in the skin, with its short life span, is the first sign of problems in nutrition. “On the one hand, nutrient deficiencies soon produce skin problems; on the other hand, proper nutrition can have a quick and powerful effect on correcting problems.” Antioxidants, and specifically the polyphenols in green tea, protect the skin in several ways. Healthy collagen and elastin are necessary to preserve a youthful look, but are easily damaged by free radicals, contributing to an older facial appearance. Flavonoids prevent damage to collagen and elastin, keeping skin stronger, smoother and more elastic. In other words, less wrinkled. “Among the polyphenols in green tea, EGCG and ECG show the strongest effect in reducing collagenase activity,” say Mitscher and Dolby.8
Many Americans suffer from allergies, which cause skin reactions such as swelling, rashes or skin irritation. Green tea relieves these symptoms “by reducing inflammation, inhibiting the release of histamine from cells, and lessening the release of other allergy-mediated chemicals in the body.”9 It also protects the skin from free radical damage caused by sun exposure. Beyond the wrinkles produced by this damage, there is the more serious concern of initiation of the carcinogenic process.
Mice and Men
As with much of today’s current research, mice were the first subjects of studies on green tea and skin. Early in the 1990s, scientists discovered that oral consumption or subcutaneous application of green tea polyphenols (GTP) inhibited inflammation and the development of cancer in lab mice.10 As stated earlier, Katiyar, Hasan Mukhtar and other associates are responsible for much of this and subsequent work. They tested GTPs for protection against chemically induced tumors and tumor promotion, conversion of benign papillomas to carcinomas, protection against ultraviolet B (UVB) radiation and the effects on skin tumor growth, all with positive results.11 Anti-inflammatory effects were also addressed, with GTPs protecting against chemical and UVB radiation promotion of edema.12
These research teams have gone on to test some of their results on human skin. In a study published in 1996, volunteers received application of GTPs prior to exposure to UV radiation on untanned backs. There was a significant reduction in erythema (redness of skin) as compared to UV exposure alone. Subsequent studies with only topical EGCG showed inhibition of chemical processes leading to inflammation and skin disease.13 According to Katiyar et al, “These data obtained in human skin demonstrate that green tea may have the potential to reduce the risk of UV-induced oxidative stress-mediated skin diseases in humans, as well as mice.”14 Overall, there is a strong indication that green tea will become “a significant pharmacologic agent for the prevention and treatment of a variety of human skin disorders.”15
Additional studies on metabolism and bioavailability of GTPs in green tea consumption by humans revealed that levels of GTPs in the blood system increase with repeated consumption. It was also suggested that slowly drinking the tea provides higher concentrations of catechins to be absorbed through the oral mucosa.16
With the increasing scientific data on green tea’s benefits, many cosmetic and pharmaceutical companies have jumped on the bandwagon to provide consumers with topical and capsule versions of the product. Katiyar et al state that “although more clinical studies are needed, supplementation of skin care products with green tea may have a profound impact on various skin disorders in the years to come.”17 However, they caution that skin care products likely have not been tested in clinical studies to assure the effectiveness of GTPs in this form, nor the concentration needed for beneficial effects.18
‘Tea Party’ Health Etiquette
Although it’s not necessary to follow the Chinese protocol for tea ceremony to reap the benefits of green tea, there are some important guidelines for adding this beverage to your daily routine. The caffeine content in brewed green tea generally ranges from 1 percent to 4 percent, far below that of coffee or black tea, but enough to be of concern to those overstimulated by caffeine. According to Mitscher and Dolby, caffeine content increases with the length of brewing time. They state, “The size of the leaves you use can also affect caffeine content. The tiny broken bits of tea leaves that fill a tea bag release twice as much caffeine as the equivalent amount of whole leaves.”19 Therefore, the amount of caffeine varies from cup to cup and there is no fool-proof way of determining just how much is being consumed.
Alternatives include using a caffeine-free green tea supplement which provides a controlled dosage of polyphenols, or buying a decaffeinated brand. Unfortunately, the decaffeinating process decreases the polyphenols. Caffeine-free or not, the level of polyphenols is always an unknown in brewed tea. Commercially prepared green tea generally contains 60 percent polyphenols, but as Mitscher and Dolby point out, “the polyphenol levels can vary as a result of many factors, including where the tea plant was grown, how it was processed, its age, and how you brewed it.”20 Green tea aficionados usually recommend a high grade, whole leaf tea over commercially produced tea bags. The larger the leaf, the better the quality, with tea bags containing primarily the remaining “dust.”21 Whatever the form for brewing, green tea should be taken without adding milk, as this can decrease the antioxidant effect.22
How much green tea should you drink to reap the benefits? Although personal lifestyle and risk factors for disease obviously enter into the equation, it is estimated that 300 to 400 mg of GTPs are needed to provide health protection. This translates into four to 10 cups daily23 (remembering that polyphenols vary cup to cup) or the standardized amount provided in supplement form of three capsules.24
From a medical point of view, there are those who should take caution with green tea products. Consultation with a physician is recommended to prevent risk of allergic reaction in those who are tea-sensitive. Additionally, the caffeine in green tea can cause a negative reaction with some medications.25 Mitscher and Dolby caution against the use of green tea for pregnant women and “women whose PMS or fibrocystic breast disease worsens after caffeine ingestion.” In these cases, a preferred choice would be decaffeinated tea or a caffeine-free green tea supplement.26 Consumption of more than 250 ml a day of green tea has been shown to interfere with iron metabolism in infants, putting them at risk of anemia. In light of the research, infants and breastfeeding mothers as well should avoid drinking green tea.27
As a final note, heralding back to the days of tried and true folk medicine, leftover tea can be used as a skin cleanser, a disinfectant for skin injuries and is especially beneficial for mild cases of acne and skin rashes.28