Green Tea May Delay Onset of Type 1 Diabetes

October 23, 2008
Drs. Stephen Hsu (left) and Kevin Gillespie. Credit: Medical College of Georgia

A powerful antioxidant in green tea may prevent or delay the onset of type 1 diabetes, Medical College of Georgia researchers say. Researchers were testing EGCG, green tea's predominant antioxidant, in a laboratory mouse with type 1 diabetes and primary Sjogren's syndrome, which damages moisture-producing glands, causing dry mouth and eyes.

"Our study focused on Sjogren's syndrome, so learning that EGCG also can prevent and delay insulin-dependent type 1 diabetes was a big surprise," says Dr. Stephen Hsu, molecular/cell biologist in the School of Dentistry.

They found it also worked well in their original disease focus.

In the mouse, EGCG reduced the severity and delayed onset of salivary gland damage associated with Sjogren's syndrome, which has no known cure.

"EGCG modulates several important genes, so it suppresses the abnormality at the molecular level in the salivary gland. It also significantly lowered the serum autoantibodies, reducing the severity of Sjogren's syndrome-like symptoms," Dr. Hsu says. Autoantibodies are antibodies the body makes against itself.

Both type 1 diabetes and Sjogren's syndrome are autoimmune diseases, which cause 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, says Dr. Hsu. Sjogren's syndrome can occur alone or secondary to another autoimmune disease, such as lupus, rheumatoid arthritis or type 1 diabetes.

The study, published in the Oct. 24 issue of Life Sciences, supports earlier research showing EGCG's impact on helping prevent autoimmune disease.

Researchers treated a control group of mice with water and a test group with a purified form of EGCG dissolved in the drinking water. At 16 weeks, the EGCG-fed mice were 6.1 times more likely to be diabetes-free than the water-fed group, and 4.2 times more likely at 22 weeks.

"Previous studies used another animal model that developed type 1 diabetes only after an injected chemical killed the insulin-producing cells. That may not accurately resemble disease development in humans, because type 1 diabetes is a genetic disease," says Dr. Hsu, the study's corresponding author.

"Our study is significant because we used a mouse model with the genetic defects that cause symptoms similar to human type 1 diabetes and Sjogren's syndrome, so the immune cells attack the pancreas and salivary glands until they are no longer functional."

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.

"It's kind of counterintuitive – why would there be proliferation of the glandular cells occurring when the present cells are not secreting saliva?" says Dr. Kevin Gillespie, first author of the study he conducted for his master's research project at MCG.

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.

"If the abnormal expression of these genes is the same in humans as in the animal model, then the second stage will be intervention and treatment with a pure form of EGCG," says Dr. Hsu.

"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."

Source: Medical College of Georgia

Explore further: New discovery makes early diagnosis of Sjogren's syndrome a reality for the first time

Related Stories

New discovery makes early diagnosis of Sjogren's syndrome a reality for the first time

December 13, 2012
(Medical Xpress)—Patients suffering from the painful autoimmune disease, Sjogren's Syndrome, will soon be able to be properly diagnosed much earlier, thanks to the discovery of novel antibodies by researchers at the University ...

New classification criteria released for research on Sjogren's Syndrome

April 12, 2012
An international team of researchers released new classification criteria for the common autoimmune condition Sjogren’s syndrome. Classification criteria are the consensus opinion of a group of experts that researchers ...

Researchers discover potential genetic trigger of autoimmune disease

June 27, 2016
Researchers at Hospital for Special Surgery (HSS) have uncovered a potential genetic trigger of systemic autoimmune disease. The study, the culmination of more than 10 years of research and published online in the journal ...

Link found between autoimmune diseases, medications, and a dangerous heartbeat condition

July 6, 2015
Mohamed Boutjdir, PhD, professor of medicine, cell biology, and physiology and pharmacology at SUNY Downstate Medical Center, has led a study with international collaborators identifying the mechanism by which patients with ...

Scleral lenses benefit patients with corneal irregularities

October 9, 2012
(Medical Xpress)—A UC Davis Health System Eye Center study found that scleral lenses, which rest beyond the limits of the cornea and cover the white part of the eye (sclera), were a good alternative for patients with corneal ...

Some drugs are going generic this year and next

August 3, 2012
Dozens of brand-name prescription drugs are losing their patent protection, allowing generic versions to enter the market and consumers to save 30 to 80 percent on those medications, said David Belian, director of media relations ...

Recommended for you

New insights into controversial diagnosis of adolescent chronic fatigue

October 23, 2017
Crucial new research could provide some clarity around the controversy surrounding the diagnosis and treatment of chronic fatigue syndrome (CFS) in adolescents. The research by the Murdoch Children's Research Institute published ...

Do boys really have a testosterone spurt at age four?

October 23, 2017
The idea that four-year-old boys have a spurt of testosterone is often used to explain challenging behaviour at this age.

New prevention exercise programme to reduce rugby injuries

October 23, 2017
A new dynamic 20-minute exercise programme, performed by rugby players before training and pre-match, could dramatically reduce injuries in the sport according to a benchmark study published today (Sunday 22 October).

Our laws don't do enough to protect our health data

October 23, 2017
Have you ever wondered why your computer often shows you ads that seem tailor-made for your interests? The answer is big data. By combing through extremely large datasets, analysts can reveal patterns in your behavior.

Expert: Be concerned about how apps collect, share health data

October 20, 2017
As of 2016 there were more than 165,000 health and wellness apps available though the Apple App Store alone. According to Rice University medical media expert Kirsten Ostherr, the Food and Drug Administration (FDA) regulates ...

Three million Americans carry loaded handguns daily, study finds

October 19, 2017
An estimated 3 million adult American handgun owners carry a firearm loaded and on their person on a daily basis, and 9 million do so on a monthly basis, new research indicates. The vast majority cited protection as their ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.