I didn’t use to drink a lot of tea in the past, preferring to indulge in coffee, soft drinks and others. Yet, for a reason or another, about two years ago I began drinking more and more tea every day, perhaps because I was surrounded by roommates doing the same thing. Now, I knew that tea was good for your health, but I never looked too much into it. What type of tea, how much and on what occasions? As I have become quite health-conscious recently, I decided to do my research homework.
Choosing Tea
All tea types come from the leaves of the tea plant (Camellia sinensis), which was originally cultivated in Southeast Asia. The difference between teas rests almost exclusively on the amount of processing being done to the leaves. White tea is processed the least, green tea – medium, while black tea – the most. The potency of positive health effects have to do with this length of processing. Basically, tea that is least processed contains the most catechins, an antioxidant that has been shown to inhibit bacteria and virus growth and other health problems. According to this, the healthiest tea should be the white tea, which is however rare and more expensive. Green tea comes second-best, and least is black tea. Nevertheless, it should not be understood that black tea is ‘bad’ or inefficient; its consumption has been shown to produce some promising health effects.
Health Studies on Tea
First of all, it must be noted that not a lot of scientific research has been done on tea until very recent years. Often, I have found these studies to be incomprehensive and unconnected, being undertaken in different institutions from Egypt to Croatia to the US. This is what I have gathered:
• Teeth: Green tea apparently reduces teeth and gum disease. A separate black tea research reported similar reductions in mouth-related diseases.
• Immune system: all forms of tea seem to be good in helping the immune system fight bacteria and viruses. However, research shows that white tea may be the most effective.
• Antibiotics: a 2008 study from Egypt shows that taking antibiotics with green tea increases the potency of the medicine. No similar research was undertaken for other types of tea.
• Bones and joints: research shows that green tea prevents and eases arthritis inflammation, cartilage breakdown and may improve bone mineral content for older women
• Cancer: so far, white tea has been shown to be most effective in cancer prevention, as it prevents cancer-mutating DNA in cells. Researchers consider white tea is most effective against colon, stomach, esophageal and other gastrointestinal cancer. Other research shows that the risk of ovarian cancer is reduced by 46% for women that consume at least 2 cups of tea (any type) per day. A Japanese study also affirms that lung cancer may be prevented or inhibited by green tea.
• Heart disease: research has shown that both green tea reduce risk of heart attack, and both green and black tea lower the danger of atherosclerosis. A 2006 Japanese study also showed that green tea is associated with lower risks of cardiovascular disease.
• Diabetes: both green and black tea prevent diabetes and reduce its ensuing complications.
• Stress Levels: research performed on black tea shows that it reduces stress hormones.
How to Keep Healthy with Tea
This brief review of several scientific studies shows that tea is a good prevention and disease-reducer for a number of serious diseases. However, as the Mayo Clinic emphasizes, further in-depth studies are required before science will admit the qualities of tea. In the meantime, perhaps there is wisdom in the health benefits Asian cultures have always attributed to tea.
So, how to keep health with tea?
• Drink more than 2-3 cups of tea per day but do not exaggerate (even if you wanted to, probably your bladder wouldn’t be able to take it!)
• Don’t forget that all tea (except herbal) contains caffeine: black tea contains roughly 1/3 of a cup of coffee, and green tea 1/6.
• As with everything consumed in excess, drinking too much (particularly black) tea may have adverse effects on health including caffeine-related problems (anxiety, sleep disorders, arrhythmias) and high fluoride-related problems (arthritis, osteoporosis, or even cancer)
• Drink tea, refrain from tea supplements. Research points out to the fact that too many tea antioxidants could cause chromosome damage and leukemia
• To the best extent, drink white tea; green tea is second best.
References
Kushiyama et al. Relationship Between Intake of Green Tea and Periodontal Disease. Journal of Periodontology, 2009; 80 (3): 372
American Society For Microbiology (2001, May 24). Tea Fights Cavities, Reduces Plaque. ScienceDaily. Retrieved March 7, 2009, from http://www.sciencedaily.com¬ /releases/2001/05/010523072047.htm
Society for General Microbiology (2008, April 1). Green Tea Helps Beat Superbugs, Study Suggests. ScienceDaily. Retrieved March 7, 2009, from http://www.sciencedaily.com¬ /releases/2008/03/080330200640.htm
National Institute Of Chemistry, Slovenia (2007, January 16). Cup Of Green Tea To Keep The Bacteria Away. ScienceDaily. Retrieved March 7, 2009, from http://www.sciencedaily.com¬ /releases/2007/01/070116132946.htm
Mayo Clinic (2008, April 6). Drinking Tea May Offer Health Benefits, But Evidence Still Limited. ScienceDaily. Retrieved March 7, 2009, from http://www.sciencedaily.com¬ /releases/2008/04/080402212206.htm
American Chemical Society (2000, April 13). Cancer-Preventive Potential Of White Tea. ScienceDaily. Retrieved March 7, 2009, from http://www.sciencedaily.com¬ /releases/2000/04/000410084553.htm
American Society For Microbiology (2004, May 28). White Tea Beats Green Tea In Fighting Germs. ScienceDaily. Retrieved March 7, 2009, from http://www.sciencedaily.com¬ /releases/2004/05/040526070934.htm
Federation of American Societies for Experimental Biology (2008, April 10). Digestive Process Affects Anti-cancer Activity Of Tea In Gastrointestinal Cells. ScienceDaily. Retrieved March 7, 2009, from http://www.sciencedaily.com¬ /releases/2008/04/080407172713.htm
University Of Southern California (2002, April 9). Polyphenols In Tea May Reduce Risk Of Stomach, Esophagus Cancers. ScienceDaily. Retrieved March 7, 2009, from http://www.sciencedaily.com¬ /releases/2002/04/020409073717.htm
JAMA and Archives Journals (2006, January 3). Drinking Tea Associated With Lower Risk Of Ovarian Cancer. ScienceDaily. Retrieved March 7, 2009, from http://www.sciencedaily.com¬ /releases/2006/01/060103085358.htm
University College London (2006, October 4). Black Tea Soothes Away Stress. ScienceDaily. Retrieved March 7, 2009, from http://www.sciencedaily.com¬ /releases/2006/10/061004173749.htm
American Chemical Society (2005, April 19). Tea May Help Prevent Diabetes And Cataracts. ScienceDaily. Retrieved March 7, 2009, from http://www.sciencedaily.com¬ /releases/2005/04/050419094700.htm
Alexopoulos et al. The acute effect of green tea consumption on endothelial function in healthy individuals. European Journal of Cardiovascular Prevention & Rehabilitation, 2008; 15 (3): 300 DOI: 10.1097/HJR.0b013e3282f4832f
"The combination of green tea and tamoxifen is effective against breast cancer." Sartippour MR, et al. Carcinogenesis. 2006 Dec;27(12):2424-33. Epub 2006 Jun 19.
Dangerous Side Effects of Tea Exposed. Bio-Medicine. Online. Available at: http://www.bio-medicine.org/medicine-news/Dangerous-Side-Effects-of-Tea-Exposed-20270-1/
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