Potential health benefits of green tea
Green tea health benefits revisited…
Green tea has several purported health benefits some of which suggest possible ergogenic or performance-enhancing effects. As such, I thought that it would be useful to review some of these possible health or performance-enhancing benefits by highlighting some of the current research on green tea or green-tea extract (epigallocatechin-3-gallate; EGCG).
Does green tea extract (EGCG) enhance endurance performance in cyclists?
Results from a recent study published in the International Journal of Sports Nutrition and Exercise Metabolism suggests that green tea extract does not offer any additional benefits to caffeine with respect to fat oxidation or endurance (Dean et al, 2009).
The dose of ECGC (green tea extract) used in this study was 270 mg over a 6 day period and 1 hour prior to exercising. Though green tea extract did not improve cycling performance, the study authors did find that 3mg/kg of caffeine supplementation did improve cycling performance.
Does green tea catechin consumption enhance fat loss?
A recent study published in the Journal of Nutrition (Maki et al, 2009) found that moderately obese subjects who consumed a beverage containing 625 mg of green tea catechins lost more abdominal fat mass than subjects who consumed a caffeine-only control drink over a 12-week time period. In addition to consuming the beverages, the test subjects and control groups both engaged in 180 > moderate exercise program.
Though both groups lost similar amounts of body fat, the catechin group lost more abdominal fat than the control group.
In yet another study on a catechin containing beverage (582.8 mg of catechins) which was published in the journal, Obesity, the study authors found that it reduced waste circumference and hemoglobin A (1c) levels after 12 weeks (Nago et al, 2009). Adiponectin which is negatively correlated with visceral obesity was significantly higher in the catechin group. All of the subjects in this study had type 2 diabetes but were not receiving insulin therapy.
Does green tea reduce cardiovascular risk factors?
Researchers at the University of Florida, Gainsville, published a recent study which study the effects of a decaffeinated green tea capsule on blood pressure, serum lipids, and oxidative stress (Nantz et al, 2009). Results of the study were as follows:
- Camellia sinensis (CSC) lowered systolic and diastolic blood pressures by 5 and 4 mmHg, respectively.
- Blood pressure remained lower for 3 months.
- 10- and 9-mg/dL reductions in total and low-density lipoprotein (LDL) cholesterol, respectively.
- CSC lowered serum amyloid-alpha by 42% (a marker of chronic inflammation) and lowered malondialdehyde by 11.9% (a marker of oxidative stress).
A similar study published in the British Journal of Nutrition (Brown et al, 2009) also found that green tea (400 mg EGCG) lowered blood pressure in test subjects while also having a positive effect on their mood.
Update: Catechins in green tea may provide protection against glaucoma.
References:
- Dean S, Braakhuis A, Paton C. The effects of EGCG on fat oxidation and endurance performance in male cyclists. Int J Sport Nutr Exerc Metab. 2009 Dec;19(6):624-44.
- Maki KC, Reeves MS, Farmer M, Yasunaga K, Matsuo N, Katsuragi Y, Komikado M, Tokimitsu I, Wilder D, Jones F, Blumberg JB, Cartwright Y. Green tea catechin consumption enhances exercise-induced abdominal fat loss in overweight and obese adults. J Nutr. 2009 Feb;139(2):264-70. Epub 2008 Dec 11.
- Nagao T, Meguro S, Hase T, Otsuka K, Komikado M, Tokimitsu I, Yamamoto T, Yamamoto K. A catechin-rich beverage improves obesity and blood glucose control in patients with type 2 diabetes. Obesity (Silver Spring). 2009 Feb;17(2):310-7. Epub 2008 Nov 13.
- Nantz MP, Rowe CA, Bukowski JF, Percival SS. Standardized capsule of Camellia sinensis lowers cardiovascular risk factors in a randomized, double-blind, placebo-controlled study. Nutrition. 2009 Feb;25(2):147-54. Epub 2008 Oct 9.
- Brown AL, Lane J, Coverly J, Stocks J, Jackson S, Stephen A, Bluck L, Coward A, Hendrickx H. Effects of dietary supplementation with the green tea polyphenol epigallocatechin-3-gallate on insulin resistance and associated metabolic risk factors: randomized controlled trial. Br J Nutr. 2009 Mar;101(6):886-94. Epub 2008 Aug 19.
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Category: Dietary Supplement, General Health, Nutrition, Weight loss
Interesting to see the study on green tea helping reduce belly fat. I’d always thought this to be true, but this really gives me something to point to.
Thanks for the article Jarret.
Hi Josh, thanks for your comment/feedback. I’ve been drinking green tea every day for the past year, well, Earl Grey/green tea which taste better, but might not be quite as beneficial.
There are tons of ways to loose weight and knowing that green tea is one of that. You may drink green tea in its raw form but I prefer to mix a bit of lemon juice and honey to it so as to make the tea taste great. Also keep in mind that there is no restriction that you should drink tea only once per day; you can drink it as often as you want, and remember that the more you drink green tea, the faster you would lose weight.
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