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2007-8-31 18:39:01 |
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A study by Medical College of Georgia researchers suggests that green tea may help protect against autoimmune disease. The suggestion came after researchers studied green tea in an animal model for type I diabetes and primary Sjogren¡¯s syndrome, which damages the glands that produce tears and saliva. They found the animals treated with green tea extract significantly reduced salivary gland damage, suggesting a reduction of the Sjogren¡¯s symptom commonly referred to as dry mouth. Dry mouth, which affects about 30 percent of elderly Americans, can be implicated by certain drugs, radiation and other diseases. Apparently, Dr. Stephen Hsu, a researcher in the MCG School of Dentistry and lead investigator on the study and colleagues were triggered to do the study by the fact that only about 5 percent of the elderly suffer dry mouth in China where consumption of green tea is common. ¡°Since it is an autoimmune disease, Sjogren¡¯s Syndrome causes the body to attack itself and produce extra antibodies that mistakenly target the salivary and lacrimal glands,¡± Hsu says. The finding can be significant as there is no cure or prevention for Sjogren¡¯s syndrome. In the study, Hsu and colleagues examined the salivary glands of the water-consuming group and a green tea extract-consuming group to see if green tea extract has any effect on inflammation and the number of lymphocytes, a type of white blood cells on the inflammation sites to fend off foreign cells. Dr. Hsu says the group treated with green tea had significantly fewer lymphocytes. Their blood also showed lower levels of auto-antibodies, which are protein weapons produced when the immune system attacks itself, he says. The results indicate that green tea extract reduced the inflammation, which is in agreement of early findings. This effect may be due to one component of green tea ¨C EGCG ¨C which has been known in early studies to help suppress inflammation, according to Dr. Hsu. ¡°So, we suspected that green tea would suppress the inflammatory response of this disease. Those treated with the green tea extract beginning at three weeks, showed significantly less damage to those glands over time.¡± These results, published in a recent issue of Autoimmunity, reinforced early findings resulting from a 2005 study conducted in a Petrie dish, Dr. Hsu says. In addition, researchers suspect that EGCG from green tea may turn on the body¡¯s defense system against TNF-alpha ¨C a group of molecules involved in systemic inflammation. ¡°The salivary gland cells treated with EGCG had much fewer signs of cell death caused by TNF-alpha,¡± Dr. Hsu says. ¡°We don¡¯t yet know exactly how EGCG makes that happen. That will require further study. In some ways, this study gives us more questions than answers.¡± Further research is needed to determine if green tea provides protection against autoimmune diseases, including lupus, psoriasis, scleroderma and rheumatoid arthritis, Dr. Hsu says. |
