10 Green Tea Side Effects You Didn’t Know About

Green tea is what you need you thought, right? But the topic is haunting you for now? Well, that’s the not-so-appealing truth for all the green tea lovers out there. Yes! There are many benefits of green tea but it has got some green tea side effects and you got to know those. So, what are the green tea side effects? Go ahead.

First of all, green tea is tea and that means it has got caffeine. You already know if you take excessive caffeine, it can lead to anxiety, nervousness, and shakiness. With that, it can affect the iron-absorbing ability of your body which can eventually lead to a set of serious problems. But there’s one thing that you must keep in your mind and that is, these green tea side effects show up if you consume green tea in excess of the green tea is of low quality.

Now after reading the above-written things, you might be wondering what green tea side effects are. So, read ahead for seeing the side effects that excessive drinking of green tea can have on you.

Stomach Problems

Caffeine is the most common culprit when it comes to stomach problems. Though green tea has got a lower caffeine amount than other tea types, still it can cause some problems because it increases the acid amount which is involved in the digestive process, causing nausea or pain. You might have read that green tea is good for preventing cancer, especially gastric cancer but the information is insufficient, my friend. So, if you experience stomach ache after green tea has been drunk, you must visit your doctor as soon as possible.

Iron Deficiency And Anemia

Did you know that excessive drinking of green tea can lead to iron-deficiency anemia? The most important thing is that if you take green tea after an iron-rich meal, it can make the main components of tea to bind with the iron. When this happens, the green tea will simply lose the potential of being an antioxidant. The main compound present in green tea is EGCG which inhibits an enzyme known as myeloperoxidase, which causes inflammation. But when the tea is taken with iron-rich foods, EGCG loses the ability to bind with myeloperoxidase.

Green tea has also got tannins that block iron absorption from food and its supplements. It decreases the iron absorption from plant-based sources. This can also result in anemia.


Again, caffeine in green tea is the reason for causing mild to severe headaches. The reason for headaches can be iron deficiency also which occurs because of excessive green tea intake. Apart from headaches, dizziness is also caused by green tea. The thing that you must note is even though green tea extract has been listed in over 100 over-the-counter herbal supplements and preparations, using it as a treatment for any of the ailments has not been regulated strictly by the FDA.


This can be another possible bad effect but can be averted by limiting the consumption of green tea, as the caffeine fatal dose is 10-14 grams estimated in a day. The reason behind this is the caffeine as it stimulates the nervous system and interferes with sleep. Well, all the lactating and pregnant women out there, you must limit your green tea intake because it might pass into the breast milk and cause insomnia in the infants who are nursing. You don’t want that, right?

Irregular Heartbeat

Ah! Again caffeine is the reason as it stimulates heart also. It can cause a condition named tachycardia, which means irregular fast heartbeat. This condition, also known as palpitations, can result in angina or chest pain and can be a serious threat.


The green tea polyphenols can cause oxidative stress, as per one Indian study. And if someone takes excessive caffeine, even if it’s from green tea, it can trigger the nauseating feeling and vomiting in that person. The moderate amount is 300-400 mg per day. So, take it in a moderate range only.


Some people, who are sensitive to caffeine a bit and are new to green tea might get diarrhea. This can subside slowly as you will get used to the beverage. But it can also occur if you have taken excessive green tea side effects! You can stop it by reducing the green tea consumption and with that, don’t drink it on an empty stomach. But if you have severe diarrhea, stop consuming green tea and consult a doctor right away as it is not normal.

Muscle Tremors And Contractions

Did you know that if you consume excessive caffeine, you can get twitching and muscle spasms? No? Well, yeah that can happen. And if you have abnormal sinus rhythm, limit your caffeine intake. Caffeine is also linked to restless leg syndrome, dear. According to one report, tremors can also be caused because of caffeine.


You know, green tea is actually acidic and that’s why it can irritate the esophageal lining and can cause heartburn or acid reflux. If you are already the patient of heartburn, the condition can get worse. There’s a preservative used, ascorbic acid, which can loosen the lower esophageal sphincter causing heartburn. According to one Japanese study, GERD is because of green tea consumption. Plus, caffeine also increases stomach ache, leading to gastritis.


Green tea extracts were tested on mice and it was found to accelerate convulsions onset. The green tea was found to increase the convulsion duration always. With that, it can also keep away folic acid from working like it must and can lead to folic acid deficiency. If folic acid is in excess, it leads to seizures where green tea can be helpful but no evidence is there for such thing.

Final Words:

According to me, green tea is great but if it’s taken within limits. As you know already, excess of anything is bad, so is the case here. Drink green tea in a moderate amount and things are good to go. Do not go for excess and get yourself in trouble.

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