Put down those saucer cups and get chugging, tea is officially awesome for our health. Before loading up on Red Zinger, make sure that "tea" is actually tea. Real tea is derived from a particular plant (Camellia sinensis) and includes only four varieties: green, black, white, and oolong. Anything else (like herbal “tea”) is an infusion of a different plant and isn’t technically tea.
But what real tea lacks in variety, it makes up for with some serious health benefits. Researchers attribute tea’s health properties to polyphenols (a type of antioxidants) and phytochemicals. Though most studies have focused on the better-known green and black teas, white and oolong also bring benefits to the table. Read on to find out why coffee's little cousin rocks our health.
Why Tea Is (Healthy and) Awesome
1. Tea can boost exercise endurance. Scientists found the catechins (antioxidants) in green tea extract increase the body’s ability to burn fat as fuel, which accounts for improved muscle endurance Green tea extract improves endurance capacity and increases muscle lipid oxidation in mice. Murase, T., Haramizu, S., Shimotoyodome, A., et al. Biological Science Laboratories, Kao Corporation, Japan. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology, 2005 Mar;288(3):R708-15..
2. Drinking tea might reduce the risk of heart attack. Tea might also help protect against cardiovascular and degenerative diseases Black tea consumption dose-dependently improves flow-mediated dilation in healthy males. Grassi, D., Mulder, TP, Draijer, R.,et al. Department of Internal Medicine and Public Health, University of L’Aquila, Italy. Journal of Hypertension, 2009 Apr;27(4):774-81..
3. The antioxidants in tea might help protect against a boatload of cancers, including breast, colon Inhibition by white tea of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine-induced colonic aberrant crypts in the F344 rat. Santana-Rios, G, Orner, GA, Xu, M, et al. Linus Pauling Institute, Oregon State University, Oregon. Nutrition and Cancer, 2001;41(1-2):98-103, colorectal Urinary biomarkers of tea polyphenols and risk of colorectal cancer in the Shanghai Cohort Study. The Cancer Center, University of Minnesota, Minnesota. Yuan, JM, Gao, YT, Yang, CS, et al. International Journal of Cancer, 2007 Mar 15;120(6):1344-50, skin, lung Green tea, black tea consumption and risk of lung cancer: a meta-analysis. Tang, N., Wu, Y., Zhou, B., et al. National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai Institute of Pharmaceutical Industry, China. Lung Cancer, 2009 Sep;65(3):274-83, esophagus, stomach, small intestine, pancreas, liver Phase IIa chemoprevention trial of green tea polyphenols in high-risk individuals of liver cancer: modulation of urinary excretion of green tea polyphenols and 8-hydroxydeoxyguanosine. Luo, H., Tang, L., Tang, M., et al. The Institute of Environmental and Human Health and Department of Environmental Toxicology, Texas Tech University, Texas. Carcinogenesis, 2006 Feb;27(2):262-8, ovarian A prospective study of dietary flavonoid intake and incidence of epithelial ovarian cancer. Gates, MA, Tworoger, SS, Hecht, JL, et al. Channing Laboratory, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts. International Journal of Cancer, 2007 Nov 15;121(10):2225-32, prostate Green tea consumption and prostate cancer risk in Japanese men: a prospective study. Kurahashi, N., Sasazuki, S., Iwasaki, M., et al. Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan. American Journal of Epidemiology, 2008 Jan 1;167(1):71-7, and oral Phase II randomized, placebo-controlled trial of green tea extract in patients with high-risk oral premalignant lesions. Tsao, AS, Liu, D., Martin, J., et al. Department of Thoracic/Head and Neck Medical Oncology, The University of Texas M.D. Anderson Cancer Center, Texas. Cancer Prevention and Research, 2009 Nov;2(11):931-41 cancers Inhibition of carcinogenesis by tea. Yang, CS, Maliakal, P., and Meng, X. Laboratory for Cancer Research, Department of Chemical Biology, College of Pharmacy, Rutgers, New Jersey. Annual Review of Pharmacological Toxicology, 2002;42:25-54. But don’t rely solely on tea to keep a healthy body: Tea might not be a miracle cure, after all The association of tea consumption with ovarian cancer risk: A metaanalysis. Zhou, B., Yang, L., Wang, L., et al. Key Laboratory of Reproductive Medicine, Department of Pharmacology, Nanjing Medical University, China. American Journal of Obstetric Gynecology, 2007 Dec;197(6):594.e1-6 A prospective clinical trial of green tea for hormone refractory prostate cancer: an evaluation of the complementary/alternative therapy approach. Choan, E., Segal, R., Jonker, D., et al. Division of Radiation Oncology, The Ottawa Hospital Regional Cancer Centre, Ontario, Canada. Urologic Oncology, 2005 Mar-Apr;23(2):108-13. While more studies than not suggest that tea has cancer-fighting benefits, current research on cancer is mixed.
4. Tea helps fight free radicals. Tea is high in Oxygen Radical Absorbance Capacity (“ORAC” to its friends), which is a fancy way of saying that it helps destroy free radicals (which can damage DNA) in the body. While bodies are designed to fight free radicals on their own, they’re not 100 percent effective—and since damage from these radical oxygen ninjas has been linked to cancer, heart disease, and neurological degeneration, we’ll take all the help we can get.
5. Tea is hydrating to the body (even despite the caffeine!) Black tea is not significantly different from water in the maintenance of normal hydration in human subjects: results from a randomised controlled trial. Ruxton, CH and Hart, VA. Nutrition Communications, Front Lebanon, Cupar, UK. British Journal of Nutrition, 2011 Aug;106(4):588-95.
6. Drinking tea can lower the risk of Parkinson’s disease. When considered with other factors like smoking, physical activity, age, and body mass index, regular tea drinking was associated with a lowered risk of Parkinson’s disease in both men and women Coffee and tea consumption and the risk of Parkinson's disease.Hu, G., Bidel, S., Jousilahti, P., et al. Department of Health Promotion and Chronic Diseases Prevention, National Public Health Institute, Finland. Movement Disorders, 2007 Nov 15;22(15):2242-8.
7. Tea might provide protection from ultraviolet rays. We know it’s important to limit exposure to UV rays, and we all know what it’s like to feel the burn. The good news is that green tea may act as a back-up sunscreen Cutaneous photoprotection from ultraviolet injury by green tea polyphenols. Elmets, CA, Singh, D., Tubesing, K., et al. Department of Dermatology, Case Western Reserve, Ohio. American Journal of Academic Dermatology, 2001 Mar;44(3):425-32.
8. Tea could keep waist circumference in check. In one study, participants who regularly consumed hot tea had lower waist circumference and lower BMI than non-consuming participants Tea consumption is inversely associated with weight status and other markers for metabolic syndrome in US adults. Vernarelli, JA and Lambert, JD. Department of Nutritional Sciences, Penn State University, Pennsylvania. European Journal of Nutrition, 2012 Jul 10. Scientists speculate that regular tea drinking lowers the risk of metabolic syndrome (which increases the risk of diabetes, artery disease, and stroke), although it’s important to remember that correlation does not equal causation.
9. Regular tea drinking might also counteract some of the negative effects of smoking Effect of increased tea consumption on oxidative DNA damage among smokers: a randomized controlled study. Hakim, IA, Harris, RB, Brown, S., et al. Mel and Enid Zuckerman Arizona College of Public Health, University of Arizona, Arizona. Journal of Nutrition, 2003 Oct;133(10):3303S-3309S and might even lessen the risk of lung cancer (good news, obviously, but not a justification for cigs).
10. Tea could be beneficial to people with Type II diabetes. Studies suggest that compounds in green tea could help diabetics better process sugars Beneficial effects of green tea: A literature review. Chacko, M., Thambi, P., Kuttan, R., et al. Chinese Medicine, 2010;5:13.
11. Tea can help the body recover from radiation. One study found that tea helped protect against cellular degeneration upon exposure to radiation, while another found that tea can help skin bounce back post-exposure Radio-modulatory effects of green tea catechin EGCG on pBR322 plasmid DNA and murine splenocytes against gamma-radiation induced damage. Richi, B., Kale, RK, and Tiku, AB. Radiation and Cancer Therapeutics Lab, Jawaharlal Nehru University, India. Mutation Research, 2012 Aug 30;747(1):62-70.
12. Green tea has been found to improve bone mineral density and strength Green tea polyphenols benefits body composition and improves bone quality in long-term high-fat diet-induced obese rats. Shen, CL, Cao, JJ, Dagda, RY, et al. Department of Pathology, Texas Tech University Health Sciences Center, Texas. Nutrition Research, 2012 Jun;32(6):448-57. Epub 2012 Jun 8.
13. Tea might be an effective agent in the prevention and treatment of neurological diseases, especially degenerative diseases (think Alzheimer’s). While many factors influence brain health, polyphenols in green tea may help maintain the parts of the brain that regulate learning and memory Green tea epigallocatechin-3-gallate (EGCG) promotes neural progenitor cell proliferation and sonic hedgehog pathway activation during adult hippocampal neurogenesis. Wang, Y., Li, M., Xu, X., Department of Medical Genetics, Third Military Medical University, China. Molecular Nutrition and Food Research, 2012 Aug;56(8):1292-303.
Steeped In Controversy - The Answer/Debate
Though most research on tea is highly positive, it’s not all definitive — so keep these caveats in mind before stocking up on gallons of the stuff:
1. Keep it cool. Repeatedly drinking hot beverages may boost the risk of esophageal cancer High-temperature beverages and Foods and Esophageal Cancer Risk -- A Systematic Review. Islami, F., Boffetta, P., Ren, J., et al. International Journal of Cancer, 2009 August 1; 125(3): 491—524. Give tea several minutes to cool off before sipping.
2. A rat does not a human make. Chemicals in tea may react differently in the lab than they do in the human body Inhibition of carcinogenesis by tea. Yang, CS, Maliakal, P., Meng, X. Laboratory for Cancer Research, Department of Chemical Biology, College of Pharmacy, Rutgers, New Jersey. Annual Review of Pharmacological Toxicology, 2002;42:25-54. Tannins (and the other good stuff in green tea) may not be bioavailable for humans, meaning tea might not always benefit human health to the same degree as in lab studies suggest.
3. All tea drinks are not created equal. The body’s access to the good stuff in tea might be determined by the tea variety, canning and processing, and the way it was brewed Catechin content of 18 teas and a green tea extract supplement correlates with the antioxidant capacity. Henning, SM, Fajardo-Lira, C., Lee, HW, et al. UCLA Center for Human Nutrition, School of Medicine, California. Nutrition and Cancer, 2003;45(2):226-35 Degradation of green tea catechins in tea drinks. Chen, Z., Zhu, QY, Tsang, D., et al. Department of Biochemistry, The Chinese University of Hong Kong, China. Journal of Agricultural and Food Chemistry, 2001 Jan;49(1):477-82.
At the very least, tea should be safe to consume — just not in excessive amounts Pharmacokinetics and safety of green tea polyphenols after multiple-dose administration of epigallocatechin gallate and polyphenon E in healthy individuals.Chow, HH, Cai, Y., Hakim, IA, et al. Arizona Cancer Center, The University of Arizona, Arizona. Clinical Cancer Research, 2003 Aug 15;9(9):3312-9 Adverse effects of concentrated green tea extracts. Schonthal, AH. Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, California. Molecular Nutrition and Food Research, 2011 Jun;55(6):874-85. So brew up a batch of the good stuff — hot or cold — and enjoy.
Do you drink tea regularly? Have you noticed any health benefits? Let us know in comments!