Supplement your 2015 health goals with green tea

Green tea has been dubbed as the ‘healthiest beverage on the planet’ by some health magazines and bloggers, but how real are these claims? Can green tea help support your healthy lifestyle and goals for the new year? Surprisingly, green tea has four important health benefits that have been shown through research and clinical trials.

• Green tea contains compounds that can help improve your health. These compounds or polyphenols are catechins and flavinoids. Polyphenols in green tea are powerful antioxidants, which help reduce the formation of free radicals in the body, thus protecting cells from damage. (8)

• Green tea has been show to aid in weight loss efforts. Although some claim that green tea can increase your fat burning and boost your metabolism, a Cochrane Review found the evidence to support these large claims was not sufficient. It has been shown however that the combination of catechins and caffeine in green tea can support efforts of weight loss and can decrease the development of obesity. (3,6)

•  Green tea can help with brain function. The presence of L-theanine along with caffeine has been shown to have mild anti-anxiety effects and improve your attention. Green tea has less caffeine than coffee (it has 25mg of caffeine per 8oz) but some report having energy and greater productivity when they drink green tea. It is recommended that your upper limit of caffeine intake in a day is approximately 300-400mg, which depends on your health condition and if you are taking any medications. (7)

• The greatest claim and most studied health benefit of green tea is its ability to lower your risk of cancer. It has been noted that in countries where green tea consumption is high (such as Japan), the incidence and risk of cancer is decreased. Looking at the biology of cancer, oxidative damage to cells (caused by free radicals) contributes to cancer development. Antioxidants have a protective effect against oxidative change, and as mentioned above, green tea is full of antioxidants. (4) The evidence is strongest for lowering the risk of three types of cancers: breast cancer, prostate cancer, and colorectal cancer. Several studies on breast cancer have found that women who drank the most green tea had a decreased risk of developing breast cancer. (5) Green tea has also been found to be associated with a decreased risk of advanced prostate cancer and colorectal cancer.(2,9) It has been shown that regular consumption of green tea may reduce your risk of colorectal cancer. The amount of tea, and the duration in years of consumption, tend to be the most important factors for protective health effects.

Adding green tea into your diet can be a great way to support your healthy life choices. A few things to consider- you should try and aim for a green tea of good quality (a personal favourite is the organic Japanese Sencha sold by David’s Tea). Secondly, it is important to remember that green tea has caffeine in it, so if you are pregnant or are on certain medications you should take this into consideration and speak with a healthcare provider. Research has shown that 2-3 cups per day (227ml cup), up to a maximum of 10 cups per day can provide you with healthy benefits! (1)

References

1. University of Maryland Medical Centre http://umm.edu/health/medical/altmed/herb/green-tea
2. Kurahashi N., Sasazuki S., Iwasaki M., Inoue M., and T. Shoichiro. Green Tea Consumption and Prostate Cancer Risk in Japanese Men: A Prospective Study. J. Epidemiol. (2008) 167  (1):  71-77.
3. Jurgens TM, Whelan AM, Killian L, Doucette S, Kirk S, Foy E. Green tea for weight loss and weight maintenance in overweight or obese adults. Cochrane Database Syst Rev. 2012 Dec 12;12:CD008650.
4. Meschino Health. Green Tea: It’s role in cancer and heart disease prevention. http://www.meschinohealth.com/ArticleDirectory/Green_Tea_Cancer_and_Heart_Disease_Prevention
5. Sun CL, Yuan JM, Koh WP, Yu MC. Green tea, black tea and breast cancer risk: a meta-analysis of epidemiological studies. Carcinogenesis. 2006 Jul;27(7):1310-5.
6. Diepvens K., Westerterp KR., Westerterp-Plantenga MS.. Obesity and thermogenesis related to the consumption of caffeine, ephedrine, capsaicin, and green tea. American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. Published 1 January 2007 Vol. 292 no. 1,  R77-R85.
7. Kelly SP, Gomez-Ramirez M, Montesi JL, Foxe JJ. L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance. J Nutr. 2008 Aug;138(8):1572S-1577S.
8. Serafini M, Ghiselli A, Ferro-Luzzi A. In vivo antioxidant effect of green and black tea in man. Eur J Clin Nutr. 1996 Jan;50(1):28-32.
9. Yang G, Shu XO, Li H, Chow WH, Ji BT, Zhang X, Gao YT, Zheng W. Prospective cohort study of green tea consumption and colorectal cancer risk in women. Cancer Epidemiol Biomarkers Prev. 2007 Jun;16(6):1219-23.

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