Green Tea: Part Two

I've written previously about the possible health benefits that can be found in green tea, but am learning more about it's potential for treatment of autoimmune disease.

Thanks to reader G., who sent me an e-mail containing research conducted by Dr. Stephen Hsu, among others.

Dr. Hsu has been a very busy researcher, in addition to being a member of the Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, USA. How busy? Go to Google Scholar, enter his name, and be prepared to be amazed by the volume of his published research. One of his papers in particular caught my attention today entitled A New Approach to Managing Oral Manifestations of Sjogren’s Syndrome and Skin Manifestations of Lupus, 29 March 2006, co-authored by Dr. Douglas Dickenson.

I'll admit that parts of the material presented in this paper is beyond my current level of understanding, specifically the parts that address the in-depth activity of specific autoantigens:

....The ubiquitously expressed endogenous autoantigens also include golgin family members, fodrins, nuclear mitotic apparatus protein (NuMA), poly(ADP)ribose polymerase (PARP), Ku, nucleolar organizer region protein (NOR-90), p80 coilin and centromere protein- C (CENP-C) (Rosen and Casciola-Rosen, 2004). Sera from lupus patients also often have high titers of anti-nuclear autoantibodies (ANAs). These autoantibodies specifically target the following autoantigens: dsDNA, Smith antigen (Sm), Sjogren’s syndrome (SS)-A/Ro, SS-B/La, poly(ADP)ribose polymerase (PARP), uridine rich 1 small nuclear ribonucleoprotein (U1 snRNP), and ribosomal-P (Reeves, 2004).

Blink.

Oh, and the part where he discusses caspase-mediated apoptosis as being responsible for the initiation of autoimmune response. Caspase-mediated apopto.....what?? This diagram from Wikipedia explains it all. Mmhm. Sure.

BUT, I and most other sjoggies, are perfectly capable of understanding this:

Sjögren’s syndrome (SS) is an autoimmune disorder that affects the salivary glands, leading to xerostomia, and the lacrimal glands, resulting in xerophthalmia. Secondary SS is associated with other autoimmune disorders such as systemic rheumatic diseases and systemic lupus erythematosis (SLE), which can affect multiple organs, including the epidermis. Recent studies have demonstrated that green tea polyphenols (GTPs) possess both anti-inflammatory and anti-apoptotic properties in normal human cells. Epidemiological evidence has indicated that, in comparison to the United States, the incidence of SS, clinical xerostomia and lupus is considerably lower in China and Japan, the two leading green tea-consuming countries. Thus, GTPs might be responsible, in part, for geographical differences in the incidence of xerostomia by reducing the initiation or severity of SS and lupus. Consistent with this, molecular, cellular and animal studies indicate that GTPs could provide protective effects against autoimmune reactions in salivary glands and skin. 

The authors go on to discuss current modes of treatment for autoimmune disease, all of which provide some measure of relief, but are not without potentially dangerous side effects. You can read more about disease modifying anti rheumatic drugs, biologic response modifiers, steroidal and non-steroidal anti inflammatory drugs, and saliva stimulants here.

In view of the less than ideal efficacy of these drugs along with significant side effects, the authors go on to discuss the use of the active ingredients in green tea - polyphenols and (-)-epigallocatechin- 3-gallate (EGCG) - as a potential source of treatment for autoimmune disease:

Autoimmune disorders such as SS and lupus are associated with three major destructive cell-based mechanisms: apoptosis of target cells, autoantigen expression/autoantibody production, and production of pro-inflammatory cytokines. If developed, strategies simultaneously targeting these three systems could provide novel preventive and therapeutic measures to combat autoimmune disorders. Epidemiology evidence suggests that green tea consumption is associated with overall improved health; specifically, in China and Japan, the two leading green tea-consuming countries, the incidence of SS is lower relative to non-green tea consuming countries such as the US. GTPs have been shown to possess the capacity to inhibit apoptosis, suppress autoantigen expression, and down-regulate inflammatory cytokines. Thus, delay of the autoimmune disease onset and/ or reduction of the severity of the symptoms might be achieved if GTPs are appropriately administered. 

(GTPs - green tea polyphenols) Bolding and parenthetical comments mine.  

Well, now. This information sent me rushing to the kitchen to set the tea kettle on for a cuppa. However, before YOU rush to the kitchen, consider this: although green tea and it's GTPs are potentially valuable in the treatment of autoimmune disease, it also contains other ingredients as well - specifically alkaloids including caffeine, theobromine, and theophylline. These alkaloids provide green tea's stimulant effects. All of which combined with the GTPs, create a compound that when concentrated or taken in large amounts, can also cause serious drug interactions. This information taken from the University of Maryland Medical Center:

Green Tea Possible Interactions:

If you are being treated with any of the following medications, you should not drink green tea or take green tea extract without first talking to your health care provider:

Adenosine -- Green tea may inhibit the actions of adenosine, a medication given in the hospital for an irregular (and usually unstable) heart rhythm.

Antibiotics, Beta-lactam -- Green tea may increase the effectiveness of beta-lactam antibiotics by reducing bacterial resistance to treatment.

Benzodiazepines -- Caffeine (including caffeine from green tea) has been shown to reduce the sedative effects of benzodiazepines (medications commonly used to treat anxiety, such as diazepam and lorazepam).

Beta-blockers, Propranolol, and Metoprolol -- Caffeine (including caffeine from green tea) may increase blood pressure in people taking propranolol and metoprolol (medications used to treat high blood pressure and heart disease).

Blood Thinning Medications (Including Aspirin) -- People who take warfarin, a blood thinning medication, should not drink green tea. Since green tea contains vitamin K, it can make warfarin ineffective. Meanwhile, you should not mix green tea and aspirin because they both prevent platelets from clotting. Using the two together may increase your risk of bleeding.

Chemotherapy -- The combination of green tea and chemotherapy medications, specifically doxorubicin and tamoxifen, increased the effectiveness of these medications in laboratory tests. However, these results have not yet been demonstrated in studies on people. On the other hand, there have been reports of both green and black tea extracts stimulating a gene in prostate cancer cells that may cause them to be less sensitive to chemotherapy drugs. Given this potential interaction, people should not drink black and green tea (as well as extracts of these teas) while receiving chemotherapy for prostate cancer in particular.

Clozapine -- The antipsychotic effects of the medication clozapine may be reduced if taken fewer than 40 minutes after drinking green tea.

Ephedrine -- When taken together with ephedrine, green tea may cause agitation, tremors, insomnia, and weight loss.

Lithium -- Green tea has been shown to reduce blood levels of lithium (a medication used to treat manic/depression).

Monoamine Oxidase Inhibitors (MAOIs) -- Green tea may cause a severe increase in blood pressure (called a "hypertensive crisis") when taken together with MAOIs, which are used to treat depression. Examples of MAOIs include phenelzine and tranylcypromine.

Oral Contraceptives -- Oral contraceptives can prolong the amount of time caffeine stays in the body and may increase its stimulating effects.

Phenylpropanolamine -- A combination of caffeine (including caffeine from green tea) and phenylpropanolamine (an ingredient used in many over-the-counter and prescription cough and cold medications and weight loss products) can cause mania and a severe increase in blood pressure. The FDA issued a public health advisory in November 2000 to warn people of the risk of bleeding in the brain from use of this medication and has strongly urged all manufacturers of this drug to remove it from the market.

It appears that the caffeine component in green tea is the culprit for many - but not all - drug interactions, so drinking decaffeinated green tea may be a better choice for those who indulge in a cup or two.

Should sjoggies drink green tea? That's food for thought.