| Green tea 'may keep arthritis, HIV at bay' Green tea, touted for its cardiovascular and anticancer benefits, has widened its therapeutic scope. BEN UKWUOMA reports on two research findings released last week unveiling its potentials in the management of rheumatoid arthritis and HIV. THE list of health enhancing properties associated with Green tea, has continued to widen as two separate studies lay claims to its potentials in easing the inflammation and pain of rheumatoid arthritis, and in the fight against Human Immuno-deficiency Virus (HIV). Before now, research suggests that Green Tea, which contains numerous compounds including flavonoid catechin, that have antioxidant and health enhancing properties, is said to protect against cancer, lowers blood cholesterol levels and reduces the clothing tendency of the blood. It also shows promise as a weight-loss aid that can promote the burning of fat and help regulate blood pressure and insulin levels But scientists found a component called epigallocatechin gallate (EGCG), which they insist prevents HIV from binding to immune system cells by getting there first. "Once EGCG has bound to immune system cells there is no room for HIV to take hold in its usual fashion," they stated. Another study conducted in the laboratory at the University of Michigan Health System, in Ann Arbor by an African researcher Salah-uddin Ahmed, also claimed that the same compound may ease the pains associated rheumatoid arthritis "It is too early" to fully recommend green tea to ease rheumatoid arthritis, he said, but the study "is a starting point." Ahmed is expected to present the research on Sunday at the Experimental Biology meeting, in Washington, D.C. For the study, Ahmed isolated cells called synovial fibroblasts from the joints of patients with rheumatoid arthritis. These cells form a lining of tissue surrounding the capsule of the joints. In patients with rheumatoid arthritis, this lining is inflamed, leading to long-term joint damage and chronic pain. Although the statistics of the number of Nigerians suffering from arthritis is not available, experts claim that the ailment is gradually emerging as apiblic health problem. Ahmed's team next cultured these cells and exposed them to the active ingredient in green tea, a compound named epigallocatechin-3-gallate (EGCG). Next, the cells were stimulated with a protein of the immune system known to play a role in causing joint degradation in rheumatoid arthritis. The protein is called cytokine interleukin-1 beta or IL-1B. "IL-1B is a major player in mediating cartilage degradation," Ahmed explained. In an earlier study, Ahmed's team found that fibroblasts pre-treated with EGCG and then stimulated with cytokine IL-1B were better able to block IL-1B's ability to produce damaging proteins and enzymes. Those proteins and enzymes can infiltrate the joints and cause the cartilage breakdown seen in people with rheumatoid arthritis. In the more recent study, the researchers focused on whether EGCG had the ability to block the activity of two potent molecules, IL-6 and cyclooxygenase-2 (Cox-2), which also play a role in breaking down bone in an RA joint. The two molecules were suppressed by the EGCG, Ahmed's team found. While he said it is difficult to quantify exactly the effect of the suppression, the EGCG "blocked them significantly," he said. EGCG also blocked the production of prostaglandin E2, another compound that can cause joint inflammation. One expert said the new green tea study was intriguing. "This study is very specific," said Stephen Hsu, an associate professor of dentistry, molecular medicine and genetics at the Medical College of Georgia in Augusta. In his own research, Hsu has found that green tea may help protect against certain autoimmune diseases, in which the body triggers an immune response, basically attacking its own cells. Hsu studied EGCG's effect in helping to inhibit an autoimmune disorder known as Sjogren's syndrome, in which the salivary glands are affected, and in lupus, in which the skin is affected. The new research by Ahmed is one of the firsts to focus on rheumatoid arthritis and green tea, Hsu said. If it bears out, it could be good news for rheumatoid arthritis patients, perhaps offering them a non-drug option to keep pain under control, he said. Ahmed cautioned that it is too soon to advise rheumatoid arthritis patients to drink green tea. On the other hand, drinking green tea certainly wouldn't hurt, he said, since it is known to have many health benefits and no known side effects. He said people might want to try drinking three or four 8-ounce cups of green tea per day. "Try different brands," he suggested. The flavours may taste slightly different. "Drink it continuously throughout the day," he said, to keep blood levels more constant. In the HIV study, researchers suggest that drinking green tea could help in the fight against HIV. However, experts said the joint Britain and United States work, which appeared in the Journal of Allergy and Clinical Immunology, was at a very preliminary stage. "We suggest that it should be used in combination with conventional medicines to improve quality of life for those infected," Prof. Mike Williamson of University of Sheffield says Williamson said: "Our research shows that drinking green tea could reduce the risk of becoming infected by HIV, and could also slow down the spread of HIV. "It is not a cure, and nor is it a safe way to avoid infection, however, we suggest that it should be used in combination with conventional medicines to improve quality of life for those infected. "Future research is also currently underway in order to determine how much effect can be expected from different amounts of tea." Keith Alcorn, senior editor of the Aidsmap web service, said tests on animals would be needed before any conclusions could be safely drawn on the potential protective effect of drinking green tea. "This study only looks at the ability of a chemical in green tea to block HIV binding to human CD4 immune cells in the test tube. "Many substances shown to prevent HIV infection in the test tube turn out to have little or no effect in real life, so I think there's a long way to go before anyone should rely on green tea to protect against HIV infection." In recent years, tea has attracted a lot of attention for its many health benefits. For years, Asian cultures have used tea for many medical purposes, and science is proving out what Asians seem to have known all along - tea has many healthy benefits. Among tea, green tea seems to provide the most health benefits. "This is because green tea, unlike black tea, is not fermented during its processing. Green tea leaves are left in their more natural state compared to the leaves that are fermented. In their natural state, tea leaves retain all of their natural anti-oxidants, known as catechins," Prof. Albert Egbuehi of the Department of Biochemistry, College of Medicine, Idi-Araba, Lagos said. Generally anti-oxidants are important to health as they said to protect the body free radicals. Free radicals are oxygen containing molecules that are created as a by-product of our digestive processes. Free radicals left unchecked is capable of damaging cells and DNA, leading to disease and ageing. For years, it was assumed that green tea was beneficial to weight loss simply because it contains caffeine. Caffeine has been shown to speed up the metabolism, helping you burn more calories each day. However, there have been studies that indicated that green tea is more effective than other caffeinated beverages in aiding weight loss, suggesting that something in addition to caffeine is doing the trick. In addition, green tea is lower in caffeine than black tea, coffee and colas, yet it aids weight loss more than any of these beverages. It is believed that this magic ingredient that makes green tea a more effective weight loss aid than its more caffeinated counterparts is the tea catechins - primarily the EGCG. To further advance this theory, a study was conducted in Japan, evaluating healthy Japanese men who were overweight. The participants in this study were divided into groups with similar weights and body mass indexes. During the 12-week study, the participants were fed either a bottle of tea containing 690 mg of tea catechins or a bottle of tea containing just 22 mg of tea catechins. At the end of the study, the group ingesting the larger amount of tea catechins each day had lost significantly more weight than the group ingesting the smaller amount of tea catechins. In addition, their BMI, waist circumference and overall body fat were reduced significantly compared to the control group. Not only did the group lose more weight and reduce their body fat significantly, but their cholesterol levels were also significantly reduced. This is just another in a long list of research studies outlining the benefits of the catechins found in green tea. And, one of the great things about using green tea as a health supplement, whether for weight loss, or overall health protection, is that green tea has no side effects. Many studies have linked green tea with a reduced risk of heart disease. This risk reduction is likely due to the fact that green tea can reduce your cholesterol levels, and seems to prevent the cholesterol that is circulating in the blood from turning into arterial plaque. In addition, green tea has been linked to a reduction in the risk of some cancers. Cultures where green tea is widely consumed are said to have significantly lower incidences of breast cancer, lung cancer, prostate cancer and gastrointestinal cancers. In some studies, green tea has even been shown to be an effective adjunct treatment for some forms of cancer. Much of the health benefits of green tea diets owe to the steaming method of making it. As opposed to black and oolong tea, which undergoes full oxidisation. Green tea diet is only gently steamed, preserving the natural antioxidants in its original form. Whether they are poured from the teapot or straight from the supplement bottle, the polyphenols in green tea are potent health-protecting substances Green tea leaves, however, are picked and dried without undergoing fermentation. The lack of fermentation results in a slightly different taste, and a higher polyphenol content in the resulting green-coloured tea. Polyphenols are naturally-occurring compounds present in a wide range of plants. Some polyphenols are responsible for colourful plant pigments, while others contribute to the taste and aroma of plants. Green tea contains four primary polyphenols: epicatechin gallate, epigallocatechin, and epigallocatechin gallate. These polyphenols are perhaps best known for their role as antioxidants. The antioxidant potential of green tea polyphenols has amazed even the scientists studying green tea. Other research indicates the following protective properties of green tea extract:
- fights the bacteria that leads to dental plaque;
- protects against disease-causing micro-organisms in the gastrointestinal tract;
- promotes the growth of beneficial bacteria in the intestine;
- exhibits possible anti-ulcer action; and,
- encourages anti-viral activity.
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