Green Tea – What is its role?

“Green tea is even better for you than you think!”

This is what a recent article in The Times highlighted while explaining what science says about the role of green tea (the most consumed beverage in the world after water), for example, in fighting obesity and diabetes, strengthening heart and brain health, and fighting cancer.

Green tea and catechin EGCG

Tea leaves are unique because they contain more catechins than any other beverage or food, one of which, EGCG, is the most powerful in protecting cells and fighting inflammation, and therefore damage caused by aging.

According to Dr. Acosta, an associate professor of nutrition at the University of Florida, when green tea is freshly brewed, it contains more EGCG than ready-made or ground green tea powders, which vary considerably in EGCG content, from 2 to 200 mg per serving. She mentions that when opting for tea powder, look for packages that indicate the EGCG content and try to consume it quickly after purchase, as after six months, the powders will lose 30 to 50 percent of their catechins, reducing their health benefits.

What is the maximum amount of green tea to consume, based on the opinions of various experts?

• Jeffrey Blumberg, a research professor of nutritional sciences at Tufts University, advises "drinking 2 to 4 cups of green tea per day, depending on your caffeine sensitivity."
• "The data suggests that the health benefits diminish after five cups," says Marilyn Cornelis, associate professor of preventive medicine at Northwestern University.
• "Heavier consumption isn't necessarily harmful, but the beneficial effects begin to wear off. You'll need to maintain this consumption for a period of time—years, not days. Over time, the effect will be cumulative," says Acosta.
• Clinical research on green tea typically involves very high doses of EGCG, using pills instead of the drink. The drink won't provide as much benefit unless you sip it throughout the day.
• It should be noted that Health Canada imposes these precautions: Consult a health care practitioner prior to use if you are pregnant or breastfeeding, if you have a liver disorder or an iron deficiency.

What research reveals about some of the effects of green tea, as it relates to:

• Obesity Management - Dr. Sara Ghoneim, a gastroenterologist at Massachusetts General Hospital and spokesperson for the American Gastroenterological Association, said, "In theory, it could help manage obesity or diabetes, but we need much more data to confirm this." However, one of the studies cited shows that green tea extract effectively increases leptin and reduces LDL in overweight and obese women after 6 weeks of treatment, even though there were no significant changes in other biochemical markers related to excess weight. ¹
• Heart Disease Prevention - According to a recent meta-analysis, regular consumption of green tea contributes to heart health, particularly by reducing blood pressure . ² Other research has shown a similar effect in postmenopausal women. ³
• In another study, it was found that it could also lower cholesterol levels . ⁴
• Protect brain health - Green tea consumption is associated with a reduced risk of Alzheimer's and Parkinson's disease . The caffeine in tea may be particularly helpful in keeping the mind sharp. While much research shows that caffeine boosts cognition in the short term, this could translate into long-term protection by blocking certain receptors in the brain that affect dopamine, which is implicated in ^Parkinson 's disease.5
• However, according to Professor Blumberg, coffee contains twice as much caffeine as tea, but green tea contains more L-theanine, which has a calming effect and improves concentration and attention.

To learn more about green tea, you can check out the full Time article right here!

To learn more about the benefits of green tea and skin protection, read here!

Discover here several other health benefits of green tea

References

1. Huang, LH., Liu, CY., Wang, LY. et al. Effects of green tea extract on overweight and obese women with high levels of low density-lipoprotein-cholesterol (LDL-C): a randomized, double-blind, and cross-over placebo-controlled clinical trial. BMC Complement Altern Med 18, 294 (2018). https://doi.org/10.1186/s12906-018-2355-x

2. Yıldırım Ayaz E, Dincer B, Mesci B. Effect of Green Tea on Blood Pressure in Healthy Individuals: A Meta-Analysis. Altern Ther Health Med. 2023 Jul;29(5):66-73. PMID: 36689359. https://pubmed.ncbi.nlm.nih.gov/36689359/#:~:text=The%20combined%20results%20of%20the,Z%20%3D%202.75%3B%20P%20%3D%20 .

3. Laura Acosta, Diane Rigassio Radler, Mindy Kurzer, Hamed Samavat, The Effect of 12-Month Green Tea Extract Supplementation and Impact of Catechol-O-Methyltransferase Genotype on Blood Pressure in Women Who Are Post-menopause, Current Developments in Nutrition, Volume 5, Supplement 2, 2021, Page 291, ISSN 2475-2991, https://doi.org/10.1093/cdn/nzab037_001 .

4. Cornelis MC, van Dam RM. Habitual Coffee and Tea Consumption and Cardiometabolic Biomarkers in the UK Biobank: The Role of Beverage Types and Genetic Variation. J Nutr. 2020 Oct 12;150(10):2772-2788. doi:10.1093/jn/nxaa212. PMID: 32805014; PMCID: PMC7549305. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7549305/pdf/nxaa212.pdf

5. Cunha RA. Neuroprotection by adenosine in the brain: From A(1) receptor activation to A (2A) receptor blockade. Purinergic Signal. 2005 Jun;1(2):111-34. doi:10.1007/s11302-005-0649-1. Epub 2005 Mar 17. PMID: 18404497; PMCID: PMC2096528. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8467199/

Maison Jacynthe disclaims all liability. All information contained on this page is not intended to replace justified allopathic treatment or to disregard the expertise of the medical profession. It is up to each individual to take charge of their own health, to inform themselves, and to make the necessary changes to improve their condition. Therapeutic supervision by a qualified health professional is obviously recommended.