It’s no secret that tea drinkers live longer and healthier lives,^1,2 but which tea delivers the most powerful antiageing effects and what sets it apart?

Studies report that the health benefits of drinking green tea are superior to black tea, specifically in terms of estimated life expectancy (years gained).² Though both green and black teas support cardiovascular health,³ green tea appears to excel in its ability to reduce the risk of coronary artery disease⁴ and hypertension.^5,6 Tea consumption also reduces the risk of dementia,^7,8 with protective effects against cognitive decline attributable to green tea.⁹ In general, tea also protects against various types of cancer, particularly oral cancer.¹⁰ Overall, the longevity perks of drinking green tea seem to outweigh those of black tea, both in terms of improving one’s lifespan and one’s healthspan.

The difference in levels of active constituents may help to explain why this difference has been observed between green tea and black tea.⁶ Green tea naturally contains higher levels of L-theanine^11-13 and epigallocatechin gallate (EGCG).^14,15

Both L-theanine^16-19 and EGCG^20-26 have demonstrated longevity benefits in preclinical studies through antiageing, antioxidant and anti-inflammatory activities, alongside other metabolic effects. There is also a plethora of evidence illustrating their anticancer effects,¹⁸ which is particularly extensive for EGCG.^27-30

Preclinical evidence highlights that L-theanine and EGCG work together. L-theanine and EGCG have been shown to synergistically promote the repair and regeneration of neural cells under amyloid stress – a model relevant to Alzheimer’s disease.³¹ Although this was an in vitro study, both L-theanine³² and EGCG metabolites^33,34 can cross the blood brain barrier (BBB) and exert neuroprotective effects.

The L-theanine content of green tea is highly variable, possibly type- and brewing time-dependent.^11-13 Unlike tea, supplements contain a set amount of L-theanine (e.g. 200 mg capsules), offering a more reliable dose so consumers can confidently reap the benefits of this constituent.

When critically assessed through a holistic lens, it is clearly too reductionistic to ascribe the health advantages of drinking tea to either L-theanine or EGCG exclusively. There is likely merit to complementing measurable therapeutic doses of L-theanine with the everyday benefits of consistently drinking green tea to reap the rewards of both.

References

1. Xiang Y, Xu H, Chen H, Tang D, Huang Z, Zhang Y, et al. Tea consumption and attenuation of biological aging: a longitudinal analysis from two cohort studies. Lancet Reg Health West Pac. 2024 Jan;42:100955. DOI: 10.1016/j.lanwpc.2023.100955

2. Tian W, Zhang Y, Wang S, Yan J, Wang Y, Pan J, et al. Association of tea consumption with life expectancy in US adults. Nutr J. 2024 Nov;23(1):148. DOI: 10.1186/s12937-024-01054-9

3. Hartley L, Flowers N, Holmes J, Clarke A, Stranges S, Hooper L, et al. Green and black tea for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev. 2013 Jun;2013(6):CD009934. DOI: 10.1002/14651858.CD009934.pub2

4. Wang ZM, Zhou B, Wang YS, Gong QY, Wang QM, Yan JJ, et al. Black and green tea consumption and the risk of coronary artery disease: a meta-analysis. Am J Clin Nutr. 2011 Mar;93(3):506-515. DOI: 10.3945/ajcn.110.005363

5. Mahdavi-Roshan M, Salari A, Ghorbani Z, Ashouri A. The effects of regular consumption of green or black tea beverage on blood pressure in those with elevated blood pressure or hypertension: a systematic review and meta-analysis. Complement Ther Med. 2020 Jun;51:102430. DOI: 10.1016/j.ctim.2020.102430

6. Naumovski N, Foscolou A, D'Cunha NM, Tyrovolas S, Chrysohoou C, Sidossis LS, et al. The association between green and black tea consumption on successful aging: a combined analysis of the ATTICA and MEDiterranean ISlands (MEDIS) epidemiological studies. Molecules. 2019 May;24(10):1862. DOI: 10.3390/molecules24101862

7. Zhu Y, Hu CX, Liu X, Zhu RX, Wang BQ. Moderate coffee or tea consumption decreased the risk of cognitive disorders: an updated dose-response meta-analysis. Nutr Rev. 2024 May;82(6):738-748. DOI: 10.1093/nutrit/nuad089

8. Jiang N, Ma J, Wang Q, Xu Y, Wei B. Tea intake or consumption and the risk of dementia: a meta-analysis of prospective cohort studies. PeerJ. 2023;11:e15688. DOI: 10.7717/peerj.15688

9. Noguchi-Shinohara M, Yuki S, Dohmoto C, Ikeda Y, Samuraki M, Iwasa K, et al. Consumption of green tea, but not black tea or coffee, is associated with reduced risk of cognitive decline. PLoS One. 2014;9(5):e96013. DOI: 10.1371/journal.pone.0096013

10. Kim TL, Jeong GH, Yang JW, Lee KH, Kronbichler A, Van Der Vliet HJ, et al. Tea consumption and risk of cancer: an umbrella review and meta-analysis of observational studies. Adv Nutr. 2020 Nov;11(6):1437-1452. DOI: 10.1093/advances/nmaa077

11. Ayakdaş G, Ağagündüz D. Determination of L-theanine and caffeine contents in tea infusions with different fermentation degrees and brewing conditions using the chromatographic method. Foods. 2025 Jun;14(13):2313. DOI: 10.3390/foods14132313

12. Boros K, Jedlinszki N, Csupor D. Theanine and caffeine content of infusions prepared from commercial tea samples. Pharmacogn Mag. 2016;12(45):75-79. DOI: 10.4103/0973-1296.176061

13. Keenan EK, Finnie MDA, Jones PS, Rogers PJ, Priestley CM. How much theanine in a cup of tea? Effects of tea type and method of preparation. Food Chem. 2011;125(2):588‑594. DOI: 10.1016/j.foodchem.2010.08.071

14. Musial C, Kuban-Jankowska A, Gorska-Ponikowska M. Beneficial properties of green tea catechins. Int J Mol Sci. 2020 Mar;21(5):1744. DOI: 10.3390/ijms21051744

15. Cabrera C, Giménez R, López MC. Determination of tea components with antioxidant activity. J Agric Food Chem. 2003 Jul;51(15):4427-4435. DOI: 10.1021/jf0300801

16. Huang Z, Jing H, Pan Y, Cai H, Zhang W, Zhu J, et al. L-theanine extends the lifespan of Caenorhabditis elegans by reducing the end products of advanced glycosylation. Foods. 2025 Jan;14(2):221. DOI: 10.3390/foods14020221

17. Chen L, Chen G, Gai T, Zhou X, Zhu J, Wang R, et al. L-theanine prolongs the lifespan by activating multiple molecular pathways in ultraviolet C-exposed Caenorhabditis elegans. Molecules. 2024 Jun;29(11):2691. DOI: 10.3390/molecules29112691

18. Li MY, Liu HY, Wu DT, Kenaan A, Geng F, Li HB, et al. L-theanine: a unique functional amino acid in tea (Camellia sinensis L.) with multiple health benefits and food applications. Front Nutr. 2022;9:853846. DOI: 10.3389/fnut.2022.853846

19. Zarse K, Jabin S, Ristow M. L-theanine extends lifespan of adult Caenorhabditis elegans. Eur J Nutr. 2012 Sep;51(6):765-768. DOI: 10.1007/s00394-012-0341-5

20. Mokra D, Joskova M, Mokry J. Therapeutic effects of green tea polyphenol (‒)-epigallocatechin-3-gallate (EGCG) in relation to molecular pathways controlling inflammation, oxidative stress, and apoptosis. Int J Mol Sci. 2022 Dec;24(1):340. DOI: 10.3390/ijms24010340

21. Tian J, Geiss C, Zarse K, Madreiter-Sokolowski CT, Ristow M. Green tea catechins EGCG and ECG enhance the fitness and lifespan of Caenorhabditis elegans by complex I inhibition. Aging (Albany NY). 2021 Oct;13(19):22629-22648. DOI: 10.18632/aging.203597

22. Yuan H, Li Y, Ling F, Guan Y, Zhang D, Zhu Q, et al. The phytochemical epigallocatechin gallate prolongs the lifespan by improving lipid metabolism, reducing inflammation and oxidative stress in high-fat diet-fed obese rats. Aging Cell. 2020 Sep;19(9):e13199. DOI: 10.1111/acel.13199

23. Xiong LG, Chen YJ, Tong JW, Gong YS, Huang JA, Liu ZH. Epigallocatechin-3-gallate promotes healthy lifespan through mitohormesis during early-to-mid adulthood in Caenorhabditis elegans. Redox Biol. 2018 Apr;14:305-315. DOI: 10.1016/j.redox.2017.09.019

24. Abbas S, Wink M. Epigallocatechin gallate from green tea (Camellia sinensis) increases lifespan and stress resistance in Caenorhabditis elegans. Planta Med. 2009 Feb;75(3):216-221. DOI: 10.1055/s-0028-1088378

25. Zhang L, Jie G, Zhang J, Zhao B. Significant longevity-extending effects of EGCG on Caenorhabditis elegans under stress. Free Radic Biol Med. 2009 Feb;46(3):414-421. DOI: 10.1016/j.freeradbiomed.2008.10.041

26. Brown MK, Evans JL, Luo Y. Beneficial effects of natural antioxidants EGCG and alpha-lipoic acid on life span and age-dependent behavioral declines in Caenorhabditis elegans. Pharmacol Biochem Behav. 2006 Nov;85(3):620-628. DOI: 10.1016/j.pbb.2006.10.017

27. Farhan M. Green tea catechins: nature's way of preventing and treating cancer. Int J Mol Sci. 2022 Sep;23(18):10713. DOI: 10.3390/ijms231810713

28. Ferrari E, Bettuzzi S, Naponelli V. The potential of epigallocatechin gallate (EGCG) in targeting autophagy for cancer treatment: a narrative review. Int J Mol Sci. 2022 May;23(11):6075. DOI: 10.3390/ijms23116075

29. Gan RY, Li HB, Sui ZQ, Corke H. Absorption, metabolism, anti-cancer effect and molecular targets of epigallocatechin gallate (EGCG): an updated review. Crit Rev Food Sci Nutr. 2018 Apr;58(6):924-941. DOI: 10.1080/10408398.2016.1231168

30. Min KJ, Kwon TK. Anticancer effects and molecular mechanisms of epigallocatechin-3-gallate. Integr Med Res. 2014 Mar;3(1):16-24. DOI: 10.1016/j.imr.2013.12.001

31. Xie X, Wan J, Zheng X, Pan W, Yuan J, Hu B, et al. Synergistic effects of epigallocatechin gallate and l-theanine in nerve repair and regeneration by anti-amyloid damage, promoting metabolism, and nourishing nerve cells. Front Nutr. 2022;9:951415. DOI: 10.3389/fnut.2022.951415

32. Takeshima M, Miyazaki I, Murakami S, Kita T, Asanuma M. l-Theanine protects against excess dopamine-induced neurotoxicity in the presence of astrocytes. J Clin Biochem Nutr. 2016 Sep;59(2):93-99. DOI: 10.3164/jcbn.16-15

33. Pervin M, Unno K, Nakagawa A, Takahashi Y, Iguchi K, Yamamoto H, et al. Blood brain barrier permeability of (-)-epigallocatechin gallate, its proliferation-enhancing activity of human neuroblastoma SH-SY5Y cells, and its preventive effect on age-related cognitive dysfunction in mice. Biochem Biophys Rep. 2017 Mar;9:180-186. DOI: 10.1016/j.bbrep.2016.12.012

34. Unno K, Pervin M, Nakagawa A, Iguchi K, Hara A, Takagaki A, et al. Blood-brain barrier permeability of green tea catechin metabolites and their neuritogenic activity in human neuroblastoma SH-SY5Y cells. Mol Nutr Food Res. 2017 Dec;61(12). DOI: 10.1002/mnfr.201700294