Epigallocatechin gallate (EGCG), a powerful antioxidant found in green tea, may prevent or delay the onset of type 1 diabetes and help prevent autoimmune disease.
Researchers at the Medical College of Georgia were testing EGCG in a laboratory mouse with type 1 diabetes and primary Sjogren’s syndrome, which damages moisture-producing glands, and for which there is no known cure.
EGCG was found to reduce the severity and delay onset of salivary gland damage associated with Sjogren’s syndrome.
“EGCG modulates several important genes, so it suppresses the abnormality at the molecular level in the salivary gland. It also significantly lowered the serum auto-antibodies, reducing the severity of Sjogren’s syndrome-like symptoms,” says Dr. Hsu, head researcher. Auto-antibodies are antibodies the body makes against itself.
Both type 1 diabetes and Sjogren’s syndrome are autoimmune diseases, causing the body to attack itself. Autoimmune disorders are the third most common group of diseases in the United States and affect about 8 percent of the population.
Sjogren’s syndrome can occur alone or secondary to another autoimmune disease, such as lupus, rheumatoid arthritis or type 1 diabetes. The study supports earlier research showing EGCG’s impact on helping prevent autoimmune disease.
Another related finding was that even when salivary cells were under attack, they seemed to be rapidly reproducing in the control group. The proliferation was suppressed in the EGCG-fed group.
The proliferation phenomenon also can be observed in psoriasis, an autoimmune disease affecting the skin and joints, says Dr. Hsu. “Normal skin cells turn over every 30 days or so, but skin cells with psoriasis turn over every two or three days.” Dr. Hsu’s group previously found that green tea polyphenols, including EGCG, inhibited rapid proliferation in an animal model for human psoriasis.
“We never thought proliferation was going on to this extent in the salivary gland, but we now believe it is tightly associated with Sjogren’s syndrome,” he says.
The next step is to observe Sjogren’s syndrome in human salivary gland samples to determine whether the study findings hold up in humans.
“The benefit of using green tea in preventing or slowing these autoimmune diseases is that it’s natural and not known to harm the body,” says Dr. Gillespie, periodontics chief resident at Fort Gordon’s Tingay Dental Clinic. “EGCG doesn’t have the negative side-effects that can be associated with steroids or other medications that could otherwise be prescribed.”
References:
Stephen Hsu, et al. Green tea may delay onset of type 1 diabetes. Medical College of Georgia. October 2008.
