April 26 (iVillage Total Health) -- Drinking a cup of green tea may help relieve dry mouth symptoms and offer protection against autoimmune diseases like type 1 diabetes, Sjogren's syndrome, lupus and rheumatoid arthritis.

Researchers at the Medical College of Georgia studied mice with type 1 diabetes and Sjogren's syndrome -- an autoimmune disorder that destroys salivary and tear glands and leads to severe dry mouth and dry eyes. In addition to Sjogren's syndrome, dry mouth can be caused by other conditions, numerous medications or radiation treatments. The study showed that mice given oral doses of green tea extract had significantly less salivary gland damage than mice given only water. Sjogren's syndrome is common among elderly people and generally only the symptoms are treated, with artificial saliva for dry mouth symptoms.

"We suspected that green tea would suppress the inflammatory response of this disease," Dr. Stephen Hsu, the study's lead author, said in a press release. "Those treated with the green tea extract beginning at three weeks, showed significantly less damage to those glands over time."

The researchers found that a plant chemical in green tea called epigallocatechin-3gallate (or EGCG) appears to inhibit the autoimmune response and suppress inflammation. According to researchers, EGCG may cause the body's defense system to block TNF-alpha, a group of proteins and molecules produced by white blood cells that. TNF-alpha plays a role in cell destruction.

"The salivary gland cells treated with EGCG had much fewer signs of cell death caused by TNF-alpha," Hsu said. "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."

Hsu said additional study may also show how the plant chemicals in green tea can affect other autoimmune diseases such as psoriasis, scleroderma, lupus and rheumatoid arthritis.

Results of the study were published in the March issue of Autoimmunity.

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