Green Tea Protects Against Autoimmune Diseases

Adapted from Green Tea Polyphenols reduce autoimmune symptoms... Autoimmunity, March 2007

According to researchers, green tea may help protect against autoimmune diseases.
 
A study of animal models for type 1 diabetes and primary Sjogren's Syndrome, which damages the glands that produce tears and saliva, found that there was significantly less salivary gland damage in a group treated with green tea extract.
 
The study  was conducted by Dr. Stephen Hsu, a School of Dentistry cell biologist and lead investigator, and his colleagues at the Medical College of Georgia, and was printed in the March 2007 volume of Autoimmunity.
 
Hsu' results reinforced findings of a 2005 study showing a similar phenomenon in a Petrie dish
 
Researchers also suspect that the EGCG in green tea can turn on the body’s defense system against TNF-alpha – a group of proteins and molecules involved in systemic inflammation.
 
TNF-alpha, which is produced by white blood cells, can reach out to target and kill cells.
 
Researchers looked for inflammation and the number of lymphocytes, a type of white blood cells that gather at inflammation sites. The group treated with green tea had fewer lymphocytes, and their blood also showed lower levels of autoantibodies, which are produced when the immune system attacks itself.
 
Epigallocatechin-3-gallate (EGCG), a component of green tea, is known to help suppress inflammation. EGCG may activate the body's defense against TNF-alpha, a group of proteins and molecules involved in systemic inflammation.
 
Approximately 30 percent of elderly Americans suffer from dry mouth, but in China, where green tea is widely consumed, only 5 percent of the elderly suffer from the problem.
 
“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.”
 
Additional study could help determine green tea’s protective role in other autoimmune diseases, including lupus, psoriasis, scleroderma and rheumatoid arthritis.

References

Autoimmunity, Vol. 40, No. 2, March 2007: 138-147
 
Medical College of Georgia April 18, 2007
 
Science Daily April 20, 2007