You’ve probably heard of the saying “too much of a good thing”. But when the thing in question is a beverage as beneficial as green tea, does it really hold true? Green tea is one of the best health drinks in the world, with the most potent amount of antioxidants in it than in any other natural food or beverage.
Undoubtedly, Green Tea Is Good For You
Science backs most of its claims of being a detoxifier, cholesterol and body-fat reducer, immunity booster, skin-cell renewer, and more.1
But How Many Cups Of Green Tea Is Good For You?
With so much going for it, anybody would be tempted to guzzle endless cups of green tea. Right? In Japanese societies, people drink out of bottles of green tea rather than cups. But there is such a thing as too much green tea. Research finds that in certain cases, too many cups of green tea may do more harm than good. Read on to find out how many cups a day is safe and if it depends on age, life stage, diseases, and the like. We bet you weren’t aware of some of these.
Three Is A Good Number
Overall, for most people, it is safe to drink two to three cups of green tea per day. According to the University of Maryland Medical Center, this leads to a daily consumption of an optimum total of 240–320 mg of polyphenols, the beneficial antioxidants present in natural foods.
Why We Say Stick To Three Cups
You may ask why restrict yourself to just three cups when there are several studies that prove drinking more than that amount is good for certain cancers and flushing your liver of toxins?4 And some may tell you that it’s because of the caffeine content in green tea. We’ll tell you otherwise.
Yes, Caffeine. But Not Just That
A cup or 8 oz of green tea contains 24–45 mg caffeine, while a cup of coffee contains about 100 mg. And the daily upper limit of caffeine is about 400 mg for normal adults and 100–200 mg for pregnant women, which means that it would take about 10 cups of green tea for you to exceed the daily caffeine quota.
It Contains Heavy Metals
Such As Aluminum
The green tea plants are also capable of accumulating high amounts of aluminum. This aluminum, on consumption of green tea, can get accumulated by the body, resulting in neurological diseases, especially in patients with renal failure who cannot flush it out of the body.5 Moreover, this aluminum has been seen to significantly decrease hemoglobin concentration.6
As Well As Lead
A study published in the Journal of Toxicology reports that all brewed teas and tea leaves, including green tea, contain lead in levels above what is accepted as normal and harmless for the human body. The accumulation of lead in the body is a serious concern, especially for pregnant women.7
It Hampers Nutrient Absorption
The catechins or the natural antioxidant phenols in green tea may have an affinity for iron, and green tea infusions can cause a significant decrease in the iron absorption from the diet. The tannins in green tea also interfere with the absorption of iron as well as of folate.8
When Should You Reduce Or Avoid Green Tea Intake?
Green tea can be harmful for certain conditions such as:
When You’re In The Family Way
If you are pregnant or trying to get there, cut down on your green tea consumption as teh beverage could decrease the absorption of iron and folate from your diet, both of which are important for the health of the fetus. Folate is an important prenatal vitamin prescribed to most mothers-to-be to protect the baby against birth defects. Iron is equally important during pregnancy to meet the requirement of blood generation for the baby.
A high dose of caffeine has also been linked to an increased risk of miscarriage and delayed growth of the fetus inside the uterus, a condition medically known as intrauterine growth retardation.9 Caffeine can also cause an increase in heart rhythm and blood pressure.10 So, if you are pregnant or breastfeeding your baby, stay well within the lower safety limit of 100 mg caffeine a day with no more than two cups a day.
If You Have Certain Diseases
Green tea is said to interfere with the medication and treatment for autoimmune disorders, including cancer. According to the University of Maryland Medical Center, chemotherapy’s efficacy may also be reduced by green tea. For this reason, it is important to get a clean chit for green tea from your oncologist if you are undergoing chemotherapy.11
If you are being treated for anemia, stay away from the beverage. As you may have already gathered, the tannins and catechins do not let your body absorb sufficient iron, and the aluminum decreases the hemoglobin concentration in blood, which itself is the chief problem in anemic patients in the first place.
Psychological Disorders, Heart Issues, And High BP
Green tea also interferes with the working of medication for psychological disorders such as nervousness, anxiety, and bipolar disorder and for unstable heart rhythm, blood pressure, contraception, and blood-thinning. Consult your medical care adviser to know if green tea can work in tandem with or against your prescribed medication.12
Drinking too much green tea may lead to insomnia because of the caffeine in the tea. While many teas such as chamomile and peppermint may help lull you into calming and relaxing sleep, too much of green tea will reverse this effect. Just like you won’t have espresso shots right before sleeping, you shouldn’t down a few cups of green tea either.
Stay away from green tea if you’re diagnosed with any of these health conditions. If not, time your healthy beverage right to enjoy its benefits.
|↑1, ↑5||Chacko, Sabu M., Priya T. Thambi, Ramadasan Kuttan, and Ikuo Nishigaki. “Beneficial effects of green tea: a literature review.” Chinese medicine 5, no. 1 (2010): 1.|
|↑2||Zhang, Min, Andy H. Lee, Colin W. Binns, and Xing Xie. “Green tea consumption enhances survival of epithelial ovarian cancer.” International journal of cancer 112, no. 3 (2004): 465-469.|
|↑3||Nagao, Tomonori, Tadashi Hase, and Ichiro Tokimitsu. “A green tea extract high in catechins reduces body fat and cardiovascular risks in humans.”Obesity 15, no. 6 (2007): 1473-1483.|
|↑4, ↑11, ↑12||Green Tea. University of Maryland School of Medicine|
|↑6||Marouani, Neila, Adel Chahed, Abderrazek Hédhili, and Mohamed Hédi Hamdaoui. “Both aluminum and polyphenols in green tea decoction (Camellia sinensis) affect iron status and hematological parameters in rats.” European journal of nutrition 46, no. 8 (2007): 453-459.|
|↑7||Schwalfenberg, Gerry, Stephen J. Genuis, and Ilia Rodushkin. “The benefits and risks of consuming brewed tea: beware of toxic element contamination.” Journal of toxicology 2013 (2013).]|
|↑8||Zijp, Itske M., Onno Korver, and Lilian BM Tijburg. “Effect of tea and other dietary factors on iron absorption.” Critical reviews in food science and nutrition 40, no. 5 (2000): 371-398.|
|↑9||Furuhashi, N., S. Sato, M. Suzuki, M. Hiruta, M. Tanaka, and T. Takahashi.”Effects of caffeine ingestion during pregnancy.” Gynecologic and obstetric investigation 19, no. 4 (1985): 187-191.|
|↑10||Caffeine Intake During Pregnancy. American Pregnancy Association|