Wu-yi Tea Weight Loss Case Studies

Tea AND Cholesterol

According to Dutch research, drinking tea protects against the build-up of cholesterol in the arteries, especially in women. Results indicated that people who drank one to two cups of tea a day were 46% less likely to develop severe atherosclerosis, rising to 69% in those who drank four cups of tea a day. The protective benefit of tea was most pronounced among women. The authors acknowledge that at least in the West, people who drink tea generally have a healthier lifestyle and diet, which may account for the findings. In this study, for example, the researchers found that people who drank more tea tended to be lean, had a healthy diet, and smoked less. However the fairly high levels of antioxidant flavonoids in black tea are thought to protect against arterial plaques, the fatty deposits that clog arteries, by preventing fat from being deposited on artery walls (Archives of Internal Medicine 1999;159:2170-2174).

Tea and Weight Loss

Green tea appears to speed up calorie burning, including fat calorie burning, according to researchers from the University of Geneva in Switzerland. The study authors report that, compared with placebo, treatment with green tea was associated with a "significant increase" (+4%) in daily energy expenditure. They believe that the caffeine interacts with the flavonoids in tea to alter the body's use of norepinephrine, a chemical transmitter in the nervous system, and increase the rate of calorie burning (American Journal of Clinical Nutrition, November 1999).

Thirty-eight men were assigned to one of two groups, and were asked to drink a bottle of oolong tea daily, containing either 22mg or 690mg
of catechins. After twelve weeks the high catechin group showed a significant reduction in body mass index, waist circumference and body-fat mass compared with the low dose group. (Am J Clin Nutr 2005; 81: 122-9).

TEA AND CANCER

In a study carried out in Japan over a ten-year period, consumption of 3 or more cups of green tea a day was shown to reduce the risk of recurrence of breast cancer (Cancer Lett. 2001, 167,175-82).

In Japan, The Saitama Cancer Research Institute has discovered that women with a history of breast cancer who drank 5 cups of tea daily were 50% less likely to have a recurrence than women who drink none or less than 5 daily cups. In a separate study, drinking strong tannin-rich tea has been shown to benefit genetic haemochromatosis, since tannates and other ligands inhibit the absorption of iron (BMJ no. 7168 (7th Nov ’98) p1330).

A Chinese study has shown that men who drink at least 1 cup of green tea per week for 6 months have a reduced risk of cancer of the colon, rectum or pancreas (Int. J. Cancer 1997, 70, 255-258).

A joint US-Chinese study carried out in China compared green tea consumption among 133 stomach cancer patients, 166 patients with colonic gastritis and 433 people with no stomach disease. They found that people who drank one to three cups of green tea daily had a 30% lower rate of stomach cancer, whilst those who drank more than three cups had a 61% lower rate (International Journal of Cancer, May 2001).

In research at the Karolinska Institute in Stockholm, finding suggests that a compound found in green tea may be useful in fighting malignant tumors, which must form new blood vessels in order to grow. Drs. Yihai Cao and Renhai Cao report that green tea, and one of its components, epigallocatechin-3-gallate (EGCG), significantly prevents the growth of new blood vessels in animals. The researchers conclude that long-term consumption of 2 to 3 cups of green tea might inhibit angiogenesis, an effect that may be beneficial in the prevention of cancers as well as other angiogenesis-dependent diseases, such as diabetic retinopathy - an eye disease that is a common cause of blindness. The researchers warn that where angiogenesis is important, as in pregnancy or in patients with healing wounds, people should not drink large amounts of tea. (Nature 1999;398:381-382).

Previous studies have shown that green tea contains powerful anti-oxidants that fight harmful free radicals. This enables green tea to reduce the risk and prevent the development of many cancers. But the effect of green tea is not limited to internal organs. It can also improve the health of the skin by preventing wrinkles, reducing damage from sunburn and even decreasing the risk of skin cancer when applied topically. A recent study reviewed several previous studies that looked at green tea and skin. Green tea taken orally or applied directly to the skin has prevented damage from ultraviolet light, which can lead to skin cancer. Mice exposed to a chemical that causes skin cancer were less likely to develop tumours if they had green tea ointment applied for 1 week prior to exposure. (Archives of Dermatology 2000;136:989-994, 1051).

In an Australian study of 254 Chinese patients with epithelial ovarian cancer and 652 healthy controls, it was found that the risk of ovarian cancer declined both with the more tea they drank and the length of time they had been drinking tea, with those drinking tea daily having only 39% of the risk (compared to non tea drinkers) and those who had drunk tea for more than 30 years having a 23% risk. (Cancer Epidemio Biomarkers Prev 2002; 11: 713-18).

TEA AND THE HEART

A US study has shown that drinking at least one cup of tea a day can reduce the risk of heart attack by 44%. The health benefits are thought to be derived from ingredients known as flavanoids, a type of antioxidant found in all types of tea. Flavanoids are thought to neutralise the effect of free radicals, a highly reactive molecule which travels around the body causing chemical reactions which can damage cells, including those in the heart tissues.

A previous Dutch investigation of more than 800 men between 65 and 84 showed that drinking even more tea - between three and four cups a day - decreased risk of death from coronary heart disease by 58%. Another study has shown that drinkers of one or more cups of black tea a day are 40% less likely to suffer a heart attack than non-drinkers, whilst coffee seems to have no significant effect on heart attack risk (American Journal of Epidemiology 1999;149:162-167). Numerous studies have proved the cardiovascular benefits of green tea. But black tea also has benefits for the heart say researchers from the University of Arizona. A study of 3,430 adults in Saudi Arabia found that those who drank more than 6 cups per day of black tea had a more than 50% lower risk of coronary heart disease compared to tea abstainers, even after adjusting for other factors such as smoking, diet and obesity.

Antioxidants called flavonoids, found in both green and black teas, are thought to help reduce blood pressure, hardening of the arteries and the amount of LDL or ‘bad’ cholesterol in the blood stream. (Preventive Medicine 2002;36:64-70).

The British Medical Journal has published a Japanese study on the benefits of green tea consumption in preventing cardiovascular disease, liver disorders and possibly cancer. The study, begun in 1986, concerned 1371 men over the age of 40. Tea consumption was classified as less than 3 cups, between 4 and 9 cups, and over 10 cups per day. It was found that consumption of green tea was significantly associated with lower serum concentrations of lipids and lipoproteins. "An increase in consumption substantially decreased serum total cholesterol and triglyceride concentrations, and this strong association remained almost unaltered even after age, cigarette smoking, alcohol consumption and relative body weight were controlled for". Interestingly it was found that those who drank the most green tea (more than 10 cups) were also the heaviest smokers, but that whilst levels of lipid peroxides were generally higher among smokers than non-smokers, those smokers who drank more than 10 cups had lipid peroxide levels similar to non-smokers. The study also showed that consumption of green tea reduced liver cell damage and resulted in slightly lower (but not abnormal) haemoglobin concentration. The study also suggests that green tea has protective effects on the development of cancer.

Tea and Skin

Dr. Stephen Hsu, a cell biologist in the Medical College of Georgia Department of Oral Biology, previously helped determine that polyphenols in green tea help eliminate free radicals, which can cause cancer by altering DNA, and can safeguard healthy cells while promoting the death of cancer cells. Now he reports that EGCG (epigallocatechin-3-gallate), the most abundant green tea polyphenol, can reactivate dying skin cells. Dr. Hsu believes this may lead to potential benefits for skin conditions such aphthous ulcers, psoriasis, rosascea, wrinkles and wounds. (J Pharmacol Exp Ther 2003).

Previous studies have shown that green tea contains powerful anti-oxidants that fight harmful free radicals. This enables green tea to reduce the risk and prevent the development of many cancers. But the effect of green tea is not limited to internal organs. It can also improve the health of the skin by preventing wrinkles, reducing damage from sunburn and even decreasing the risk of skin cancer when applied topically. A recent study reviewed several previous studies that looked at green tea and skin. Green tea taken orally or applied directly to the skin has prevented damage from ultraviolet light, which can lead to skin cancer. Mice exposed to a chemical that causes skin cancer were less likely to develop tumours if they had green tea ointment applied for 1 week prior to exposure. (Archives of Dermatology 2000;136:989-994, 1051).

Epigallocatechin gallate, or EGCG, an antioxidant found in green tea is at least 100 times more effective than vitamin C and 25 times better than vitamin E at protecting cells and their genetic material, DNA, from damage believed to be linked to cancer, heart disease and other potentially life-threatening illnesses, according to research carried out at the University of Kansas Lawrence. The antioxidant has twice the antioxidant benefit of resveratrol, found in red wine. Green tea has another advantage over vitamin E in that excessive amounts of antioxidants found in water soluble green tea are excreted by the body, whilst the body absorbs and retains fat-based vitamins such as vitamin E, even at potentially harmful levels.

Tea and Infection

A study carried out at Brigham and Women’s Hospital and Harvard Medical School has indicated the mechanism by which tea is able to help fight infections. Immune T cells in the body are can recognise antigens such as those found in tumour cells, bacteria, parasites and fungi, and then stimulate the production of antibodies to fight infection. Once exposed to antigens, the T cells remember them when exposed again, thus developing immunity. Now similar antigens have been found in tea, and the researchers discovered that the tea antigens tea were able to prime the T cells to remember how to respond to subsequent antigens, even when the source of the antigens was bacterial, thus helping to provide natural resistance. (Proceedings of the National Academy of Sciences).

Dr Yoshimasa Yamamoto, of Showa University in Japan, says green tea contains chemicals called catechins that "show strong antibacterial activity" against helicobacter, a bacterium which earlier this decade was discovered to be the cause of the majority of stomach ulcers. "The level required for such activity… is easily reached in the stomach after drinking a cup of green tea," he told the American Society of Microbiology's annual conference. And a Dutch team has found that garlic, even in low concentrations, especially when taken in conjunction with chemicals that reduce stomach acidity, also inhibits the growth of Helicobacter.

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