Tea, especially green tea, ranks as the second most consumed beverage globally after water. Its popularity is well-deserved due to its numerous health benefits, particularly those attributed to green tea.
While some of these benefits are well-documented by research, others are more speculative. Social media influencers often tout green tea as “nature’s Ozempic,” claiming it’s as effective as certain obesity medications. However, this comparison is largely exaggerated.
Green tea is rich in catechins, compounds that protect cells from damage as we age. It is considered healthier than other teas like black or oolong because it undergoes minimal processing, preserving more catechins. Among these catechins, EGCG (epigallocatechin gallate) is the most potent for safeguarding cells and fighting inflammation. Freshly brewed green tea contains more EGCG than pre-mixed or powdered versions, which can vary widely in their EGCG content from 2 to 200 mg per serving. Powders also lose a significant portion of their catechins after six months on the shelf, so it’s best to consume them quickly.
For optimal health benefits, aim to drink 2 to 4 cups of green tea daily, adjusting for caffeine sensitivity. Benefits tend to plateau after five cups, so more isn’t necessarily better. Over time, maintaining this intake can have a cumulative positive effect.
Contrary to what some TikTok influencers suggest, green tea is not a substitute for obesity medications like Ozempic. A clinical trial they referenced found that green tea did not significantly affect GLP-1 levels, a hormone that promotes feelings of fullness and lowers blood sugar.
A 2017 review also found no evidence that green tea affects blood glucose levels. However, some experts believe it could inhibit carbohydrate absorption, potentially reducing glucose levels. Other studies suggest that green tea’s catechins might contribute to feelings of fullness and aid in weight loss, but more data is needed to confirm these effects.
Clinical research often uses high doses of EGCG in pill form rather than the drink itself. These “green tea extract” pills can provide up to 800 mg of EGCG, far more than you’d get from drinking green tea all day. High doses of EGCG might damage the liver if taken regularly over many years, although this affects only about 5% of people. Basic animal research suggests high doses can harm the liver when fasting from food, making it more vulnerable.
Excessive green tea consumption may also cause nausea or acid reflux, especially for those sensitive to tea. It’s advisable to start with a couple of cups and see how your body reacts. The weight loss effects of drinking a few cups per day would be very gradual—similar to losing a pound over 12 weeks. Green tea is not a drug and won’t have an overwhelming effect, but gradual, moderate weight loss is the healthiest kind.
Green tea supports heart health by decreasing blood pressure and potentially lowering cholesterol levels. It has been shown to reduce bad cholesterol (LDL) and increase good cholesterol (HDL), which may contribute to its beneficial impact on cardiovascular disease. However, most research indicates that only about 5% of green tea’s catechins are absorbed into the bloodstream. Mixing green tea with vitamin C sources like lemon juice or blended strawberries can enhance absorption.
Drinking green tea is also linked to a lower risk of Alzheimer’s and Parkinson’s diseases. The caffeine in green tea helps keep the mind sharp by blocking certain brain receptors involved in Parkinson’s disease. While coffee has more caffeine, green tea contains L-theanine, which has a calming effect and improves focus.
The idea that green tea “detoxifies” the body is inaccurate. While EGCG spurs healthy adaptations, it can become toxic if not transformed and eliminated by the body. Bold claims about green tea’s ability to combat cancer are also not fully supported by research. A large review in 2021 found little evidence for green tea’s role in preventing cancer. However, lab studies suggest EGCG might block pathways involved in tumour formation.
There is some evidence that green tea may reduce the risk of certain cancers like breast, ovarian, prostate, and neck cancers as part of a healthy lifestyle. In theory, high doses could promote the death of cancerous cells, but more research is needed. An internal medicine physician diagnosed with advanced ovarian cancer saw improvements in her cancer biomarkers after drinking 6 to 8 mugs of green tea daily instead of taking extract pills—without changing her regimen. However, this experience might be unique as antioxidants in tea could interfere with certain cancer treatments.
Green tea is indeed a healthy choice with multiple benefits for heart and brain health. While it may aid in weight management and offer some protective effects against certain cancers, it should not be seen as a substitute for medications or treatments without further evidence. Enjoying 2 to 4 cups daily can be part of a healthy lifestyle with cumulative benefits over time.
