How Green Tea Can Boost Your Energy and Metabolism
Green tea is really seeing a resurgence in popularity in the public, whether it’s a warm pot of tea or an iced matcha – it seems like everyone and their mum is drinking it. While it might be a recurring trend when it comes to drinks, green tea extract has been popular in nutritional supplements for many years.
Green tea extract benefits a wide range of people and conditions, with research pointing to its efficiency to help speed up the metabolism, boost your energy, and give you the edge when it comes to working towards weight loss.
Green Tea Extract for Weight Loss
Green tea extract has been heavily researched for its benefits in assisting weight loss.
Rich in catechins (natural polyphenolic phytochemicals known for their antioxidant effects) and containing caffeine, it’s understood that the combination of the two is what is responsible for green tea extract’s weight loss assisting properties.
Catechin and caffeine have been shown in research to aid in weight loss, by regulating hormones that can enhance thermogenesis, the process where the body burns calories to digest food and produce heat. Green tea extract has been shown to boost the thermogenic process by making the body more effective at burning calories, leading to weight loss.
A 2005 study followed 14 people taking a capsule containing caffeine, green tea extract, and guarana extract before each meal. Researchers looked at the effect on calorie burning and found on average the program participants burned an average of 179 more calories in the following 24 hours.
A 12 week study released in 2016 looked at 115 women with obesity (with a higher concentration of fat in their stomach) who took either green tea extract or a placebo each day. The women who took green tea extract experienced significant weight loss and saw their waist circumference, cholesterol levels, and BMI decrease, compared with those who took a placebo.
Research is mixed on what elements of green tea extract aid in weight loss. A lot of the studies point to caffeine being the part of green tea extract that is the benefit to weight loss. Those who regularly consume high amounts of caffeine (the equivalent of around three cups of coffee or 300mg per day) may not experience as high a weight loss effect of green tea extract.
Antioxidant Power of Green Tea Extract
Some of green tea extract’s strongest health benefits come from its high levels of antioxidants. Antioxidants can help reduce oxidative stress in the body, by protecting against cell damage associated with aging and disease.
Several studies have shown that green tea extract increases the body’s antioxidant capacity and protects against oxidative stress, which may lead to preventing associated health concerns. One study in 2012 saw 35 people with obesity take 870mg of green tea extract for 8 weeks, seeing their blood antioxidant capacity increase on average from 1.2 to 2.5 micromoles per litre.
Aid Post Workout Recovery with Green Tea
A good workout can do wonders for the mind, body, and soul – but the little aches and niggles that you can get afterward aren’t the best! Research into green tea and exercise shows it can help improve exercise performance and enhance recovery.
The antioxidant powers of green tea extract come into play with post workout recovery, with the green tea catechin linked to reducing cell damage and delaying muscle fatigue. A study of 35 males showed that taking green tea extract while strength training over four weeks enhanced the antioxidant protection of the body. This study was backed up by another, following 16 sprinters over four weeks. Taking green tea extract, results showed increased protection against oxidative stress that was produced during repeated sprints.
There are also potential benefits of green tea extract on athletic performance. One study of 14 regular exercisers, saw their running distance increase by more than ten percent over four weeks of taking green tea extract.
Need a Brain Boost? Green Tea Extract!
Another win for the antioxidant powers of green tea is for the brain. The antioxidants in green tea extract, especially the compound epigallocatechin-3-gallate (EGCG), have been shown to protect brain cells from oxidative stress. Studies have shown this protection to help reduce brain damage that can lead to mental decline and brain diseases including Alzheimer’s and dementia.
Research has also linked green tea extract to helping aid memory. A 2014 study followed 12 people, who either drank a soft drink with a small amount of green tea extract, or a placebo. After consumption, the participants were tasked to work on memory tests, while brain images were taken to assess how they functioned. The group who consumed the green tea extract saw an increase in brain function and improved performance at their tasks when compared to the group who drank the placebo drink.
Boost your Liver and Heart Health with Green Tea Extract
The catechins in green tea extract have also been linked to reducing inflammation caused by some liver diseases.
A study released in 2016 gave 80 participants aged between 20 and 50 with non-alcoholic fatty liver disease either 500mg of green tea extract or a placebo, daily for three months. Those who received the green tea extract saw significant reductions in their levels of liver enzymes, an indication of improved liver health.
Another study of patients with the disease saw them drink 700ml of green tea daily for 12 weeks. Those studied saw significant decreases in liver fat content, inflammation, and oxidative stress.
It is however important for people with liver issues to have their function level tested regularly if consuming green tea, because excessive amounts of the catechins found in green tea have been found to cause harm to the liver.
Green tea extract has also been linked to benefits for healthy hearts. Green tea’s antioxidant properties can help to decrease inflammation and in turn help reduce blood pressure. They are also linked to stopping fat absorption in cells, helping to reduce blood fat levels.
A 2012 study of people with both obesity and high blood pressure, saw participants take 379mg of green tea extract daily for three months. They saw a significant decrease in blood pressure compared to a group who took a placebo, as well as reductions in their blood fat levels, including total and LDL (bad) cholesterol.
Green Tea Extract… Are The Benefits Endless?
It seems like it! While we’ve gone into some of the potentially significant health benefits in this post, green tea extract has been linked to several other potential health benefits including when it comes to reducing cancer, healthier skin (including reducing sun damage exposure and reducing acne redness), lowering blood sugar and more.
Potential Side Effects of Green Tea Extract
In rare cases, green tea can harm the liver.
The Therapeutic Goods Administration (TGA) requires this warning on the label of any listed product made after the 1st of March 2024.
“In rare cases, Camellia sinensis may harm the liver. Stop use and see a doctor if you have yellowing skin/eyes, or unusual: fatigue, nausea, appetite loss, abdominal pain, dark urine, or itching.”
Therefore, it’s important to consult with a health professional before adding green tea extract into your diet, particularly if you have concerns about your liver function.
How Much Green Tea Extract to Take?
The amount of green tea extract you should take depends on the purpose you’re taking it for. It’s always recommended to contact a health professional if you’re looking to add a supplement to assist with health benefits.
Green tea extract is recommended to be taken by adults only.
Green tea contains caffeine, therefore we recommend being aware of your caffeine intake, especially if combining with other supplements containing caffeine.
The general recommended dose of green tea extract is between 250 and 500mg per day taken with food, but it is important to consider your regular caffeine intake as part of this.
How to Take Green Tea Extract?
While you very well could take it as a powder, that would be time consuming and a bit messy! If you’re looking at adding green tea extract to your diet, we’d recommend looking into a capsule supplement to make it easier to take daily.
Ebony is our resident wordsmith here at Bulk! A reforming journalist and a graduate of the University of Tasmania, she's our resident copywriter, cat mum, pilates princess and (self appointed) Chief Swiftie!
More about Ebony AbblittReferences:
- Rains, T.M., Agarwal, S. and Maki, K.C. (2011). Antiobesity effects of green tea catechins: a mechanistic review. The Journal of Nutritional Biochemistry, 22(1), pp.1–7. doi: https://doi.org/10.1016/j.jnutbio.2010.06.006.
- Bérubé-Parent, S., Pelletier, C., Doré, J. and Tremblay, A. (2005). Effects of encapsulated green tea and Guarana extracts containing a mixture of epigallocatechin-3-gallate and caffeine on 24 h energy expenditure and fat oxidation in men. The British Journal of Nutrition, [online] 94(3), pp.432–436. doi: https://doi.org/10.1079/bjn20051502.
- Rondanelli, M., Riva, A., Petrangolini, G., Allegrini, P., Perna, S., Faliva, M.A., Peroni, G., Naso, M., Nichetti, M., Perdoni, F. and Gasparri, C. (2021). Effect of Acute and Chronic Dietary Supplementation with Green Tea Catechins on Resting Metabolic Rate, Energy Expenditure and Respiratory Quotient: A Systematic Review. Nutrients, [online] 13(2), p.644. doi: https://doi.org/10.3390/nu13020644.
- Clark, K.S., Coleman, C., Shelton, R., Heemstra, L.A. and Novak, C.M. (2019). Caffeine enhances activity thermogenesis and energy expenditure in rats. Clinical and Experimental Pharmacology and Physiology, 46(5), pp.475–482. doi: https://doi.org/10.1111/1440-1681.13065.
- Vázquez Cisneros, L.C., López-Uriarte, P., López-Espinoza, A., Navarro Meza, M., Espinoza-Gallardo, A.C. and Guzmán Aburto, M.B. (2017). Effects of green tea and its epigallocatechin (EGCG) content on body weight and fat mass in humans: a systematic review. NutricionHospitalaria, [online] 34(3), pp.731–737. doi: https://doi.org/10.20960/nh.753.
- Chen, I-Ju., Liu, C.-Y., Chiu, J.-P. and Hsu, C.-H. (2016). Therapeutic effect of high-dose green tea extract on weight reduction: A randomized, double-blind, placebo-controlled clinical trial. Clinical Nutrition, [online] 35(3), pp.592–599. doi: https://doi.org/10.1016/j.clnu.2015.05.003.
- Catarino, M.D., Alves-Silva, J.M., Pereira, O.R. and Cardoso, S.M. (2015). Antioxidant capacities of flavones and benefits in oxidative-stress related diseases. Current Topics in Medicinal Chemistry, [online] 15(2), pp.105–119. Available at: https://pubmed.ncbi.nlm.nih.gov/25547095/ [Accessed 24 Mar. 2024].
- Lowe, G.M., Gana, K. and Rahman, K. (2015). Dietary supplementation with green tea extract promotes enhanced human leukocyte activity. Journal of Complementary and Integrative Medicine, 12(4). doi: https://doi.org/10.1515/jcim-2014-0042.
- Basu, A., Betts, N.M., Mulugeta, A., Tong, C., Newman, E. and Lyons, T.J. (2013). Green tea supplementation increases glutathione and plasma antioxidant capacity in adults with the metabolic syndrome. Nutrition Research (New York, N.Y.), [online] 33(3), pp.180–187. doi: https://doi.org/10.1016/j.nutres.2012.12.010.
- Machado, Á.S., da Silva, W., Souza, M.A. and Carpes, F.P. (2018). Green Tea Extract Preserves Neuromuscular Activation and Muscle Damage Markers in Athletes Under Cumulative Fatigue. Frontiers in Physiology, [online] 9, p.1137. doi: https://doi.org/10.3389/fphys.2018.01137.
- Jówko, E., Sacharuk, J., Balasińska, B., Ostaszewski, P., Charmas, M. and Charmas, R. (2011). Green tea extract supplementation gives protection against exercise-induced oxidative damage in healthy men. Nutrition Research, 31(11), pp.813–821. doi: https://doi.org/10.1016/j.nutres.2011.09.020.
- Jówko, E., Długołęcka, B., Makaruk, B. and Cieśliński, I. (2014). The effect of green tea extract supplementation on exercise-induced oxidative stress parameters in male sprinters. European Journal of Nutrition, 54(5), pp.783–791. doi: https://doi.org/10.1007/s00394-014-0757-1.
- Roberts, J.D., Roberts, M.G., Tarpey, M.D., Weekes, J.C. and Thomas, C.H. (2015). The effect of a decaffeinated green tea extract formula on fat oxidation, body composition and exercise performance. Journal of the International Society of Sports Nutrition, 12(1), p.1. doi: https://doi.org/10.1186/s12970-014-0062-7.
- Fukutomi, R., Ohishi, T., Koyama, Y., Pervin, M., Nakamura, Y. and Isemura, M. (2021). Beneficial Effects of Epigallocatechin-3-O-Gallate, Chlorogenic Acid, Resveratrol, and Curcumin on Neurodegenerative Diseases. Molecules, 26(2), p.415. doi: https://doi.org/10.3390/molecules26020415.
- Pervin, M., Unno, K., Ohishi, T., Tanabe, H., Miyoshi, N. and Nakamura, Y. (2018). Beneficial Effects of Green Tea Catechins on Neurodegenerative Diseases. Molecules : A Journal of Synthetic Chemistry and Natural Product Chemistry, [online] 23(6). doi: https://doi.org/10.3390/molecules23061297.
- Schmidt, A., Hammann, F., Wölnerhanssen, B., Meyer-Gerspach, A.C., Drewe, J., Beglinger, C. and Borgwardt, S. (2014). Green tea extract enhances parieto-frontal connectivity during working memory processing. Psychopharmacology, [online] 231(19), pp.3879–3888. doi: https://doi.org/10.1007/s00213-014-3526-1.
- SAKATA, R., NAKAMURA, T., TORIMURA, T., UENO, T. and SATA, M. (2013). Green tea with high-density catechins improves liver function and fat infiltration in non-alcoholic fatty liver disease (NAFLD) patients: A double-blind placebo-controlled study. International Journal of Molecular Medicine, [online] 32(5), pp.989–994. doi: https://doi.org/10.3892/ijmm.2013.1503.
- Askari, G., Pezeshki, A., Safi, S., Feizi, A. and Karami, F. (2016). The effect of green tea extract supplementation on liver enzymes in patients with nonalcoholic fatty liver disease. International Journal of Preventive Medicine, 7(1), p.28. doi: https://doi.org/10.4103/2008-7802.173051.
- Hu, J., Webster, D., Cao, J. and Shao, A. (2018). The safety of green tea and green tea extract consumption in adults – Results of a systematic review. Regulatory Toxicology and Pharmacology, [online] 95, pp.412–433. doi: https://doi.org/10.1016/j.yrtph.2018.03.019.
- Bogdanski, P., Suliburska, J., Szulinska, M., Stepien, M., Pupek-Musialik, D. and Jablecka, A. (2012). Green tea extract reduces blood pressure, inflammatory biomarkers, and oxidative stress and improves parameters associated with insulin resistance in obese, hypertensive patients. Nutrition Research, 32(6), pp.421–427. doi: https://doi.org/10.1016/j.nutres.2012.05.007.
