Green tea for colorectal cancer screening

Scientific study examines the effects of green tea as colorectal cancer screening

25/09/2011

In natural medicine, green tea extracts are ever considered as a health-promoting remedy. Researchers from the Universities of Halle and Ulm have now started a long-term study to provide scientific evidence for the efficacy of green tea for the prevention of colorectal cancer. Already several smaller evidence-based studies had pointed to positive effects of the tea from the Far East.

More than 70,000 people get colon cancer each year. Malignant tumors in the intestine are among the most common causes of death in Germany, along with other cancer conditions. Naturopaths and more and more doctors believe in the healing power of green tea for the prevention of colon cancer and other cancers. Scientists from the Universities of Halle and Ulm have now started a long-term study, which should prove efficacy in particular for the prophylaxis of polyps in the intestine.

Intestinal polyps are first indications of the development of colorectal cancer
In particular, people over the age of 50 often have risk factors for the development of malignant bowel disease. Every third person from this liver age is particularly endangered. Thomas Seufferlein from the University Hospital Halle reports. The first indications of an increased risk are intestinal polyps. Anyone who regularly goes to the medical precaution, has the chance that the polyps are recognized in time and removed. Nevertheless, an increased risk of disease remains says the physician and study leader. Many patients who have ever had polyps in the intestine, after some time show a re-formation of intestinal polyps. This inevitably increases the overall risk of developing colon cancer later on. For the researchers, the question now arises for this patient group as to how the development of cancer can be effectively prevented.

For this reason, the two universities started a joint project. In the search for suitable active ingredients, the specialists have come across green tea. Previous studies had shown that the plant hormone epigallocatechin-3-gallate (epigallocatechin gallate, EGCG) contained in the green tea extract can inhibit the development of malignant tumors. From October of this year, the world's largest study on this topic begins. Especially for this purpose 3000 subjects from all over Germany were searched. All participants are over 50 years old and have been examined at least once by colonoscopy. In addition, at least one polyp in the intestine was removed from all project participants. During the study period, all subjects must take two high-concentration green tea capsules every day for three years. During the course of the study and at the end it is examined whether and when new intestinal polyps formed. "The study recruitment runs over three years, as the subjects participate staggered“, says Thomas Seufferlein. The subjects come from a total of thirty clinics and outpatient practices from all over Germany. Beforehand, the patients were asked if they wanted to participate in the project.

Instead of tea, extracts are administered in the form of capsules
However, the study participants do not drink tea, but take extracts in the form of capsules. For the quantity of a two cups is not sufficient, so that effects can unfold completely. "You would need to drink seven to nine cups of tea a day for over three years, which you can handle, but you may not always have green tea with you, and green tea contains caffeine.“ The latter could disturb the sleep in the evening, as the professor points out. The caffeine was therefore secreted before, so that the drugs do not cause sleep disorders. In the capsules themselves, the concentrated plant hormone is epigallocatechin-3-gallate. For a comparison to be made, one group also receives a non-effective placebo. Nobody knows who will be taking green tea capsules or who is consuming placebos daily. The researchers want to draw an objective comparison. In the further course, blood is taken from the project participants, the liver values ​​are measured and the blood pressure is checked. In addition, all subjects groups are asked whether they have drunk in addition to green tea or take other medicines. At the end of the study, everyone has to undergo colonoscopy.

Green tea with potency without side effects
The doctors do not expect any side effects during the project period. The green tea extract contains plant hormones that inhibit the formation of tumors. It has been scientifically proven that polyps are a precursor to the formation of carcinomas. The physicians consciously rely on a natural plant substance for cancer prevention in their study work. Finally, they want to prevent otherwise healthy people with safe plant ingredients, as Seufferlein emphasized. Drugs have a majority of side effects, which could then cause health problems. Therefore, you use a drug that does not require any side effects or side effects, yet is as effective as a drug of the previous studies. The researchers are expecting first conclusive results in six to seven years at the earliest.

The German Cancer Aid finances the study work with a total of 2.1 million euros. The funds come in the majority of donations. As a spokeswoman stressed, one wants „to exhaust all possibilities for cancer screening“. Explicitly include natural remedies, as Christina Tschoepe said.

Far Eastern remedy of naturopathy
Green tea has been grown in China for several thousand years and is one of the national drinks there. Several studies were already on the track of the green mean of natural medicine. This is what the Japanese proved „Ohsaki Study“ In 2006, the consumption of five cups of green tea daily significantly reduces the risk of cardiovascular disease. Risk reduction was 12% for men and 23% for women. Another Japanese study showed that green tea and red-bush tea developed a preventive effect against diabetic nephropathy. Regular tea consumption also reduces the risk of cancer and osteoporosis. (Sb)

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Image: Michael Grabscheit