Health Matters: Side Effects Of Green Tea

Health Matters: Side Effects Of Green Tea

Going green is the key, they said. And that’s what we believed too.And we started taking green tea. All well, until some guy in some laboratory, does some research and comes up with something not-so-appealing.

That green tea has side effects. And we better believe that too. Because yes, green tea has side effects. And you gotta know them. All of them. But, is green tea bad for health?

Read on!

How Can Green Tea Be Bad For You?

Firstly, it’s about caffeine. Green tea is, you know, tea. And like any tea, it contains caffeine. That’s something we must accept first. Excessive caffeine intake has been linked to nervousness, shakiness, and anxiety. And people who are intolerant to caffeine suffer further – they experience the symptoms even with little amounts of caffeine (or green tea, contextually speaking).

Also, green tea can hurt your body’s ability to absorb iron. Now, that’s a problem. A deficiency of iron can bestow upon you a whole set of serious problems. You don’t want that. Green tea also interacts with certain medications, and the repercussions are painfully unpleasant.

Drinking green tea in excess can result in caffeine overload, which subsequently causes insomnia, upset stomach, tremors, restlessness, etcetera. Of course, this is more prominent in people who tend to consume it in excess all of a sudden.

In other words, if you are sensitive to caffeine, you are more susceptible to the side effects.

Alright. Now to the real deal. The side effects of green tea, in detail. But before we proceed, there is one thing I want to make very clear – there are no cases of green tea causing issues when consumed in moderation. And, the quality matters too.

Hence, if someone has side effects with green tea, it is either because they consumed it in excess, or had a low-quality tea, or are caffeine sensitive. Most probably.

The Side Effects Of Green Tea

Are there any side effects of green tea? You might be wondering why green tea is bad for you, well check out for yourself here. Mentioned here are some of the surprising green tea health risks.

1. Stomach Problems

 Caffeine could be the most common culprit. Though it has a lower amount of caffeine than other types of tea, it still can cause problems. This is because caffeine increases the amount of acid involved in the digestive process. This can cause pain or nausea.


2. Iron Deficiency And Anemia

 As per a Taiwanese study, consuming too much of green tea could lead to iron deficiency anemia. More importantly, taking green tea after an iron-rich meal can make the main compounds in the tea bind to the iron. If this happens, the green tea will lose its potential as an antioxidant.


3. Headaches

Again, because of the caffeine, green tea might cause mild to severe headaches. And headaches can also be caused by iron deficiency, which, as we have seen already, could occur through an excessive intake of green tea.

Apart from headaches, green tea can also cause dizziness. And as per studies, the maximum tolerated dose of green tea in humans is 9.9 grams per day – which is roughly equivalent to 24 cups of the beverage in a day.

4. Might Cause Insomnia

Another possible bad effect of green tea is a problem with sleeping. This can be averted by limiting green tea consumption, as the fatal dose of the caffeine in green tea is estimated to be 10 – 14 grams in a day.

Taking green tea too late in the day can also cause this effect. One very obvious reason for this is the caffeine, which stimulates the nervous system and can interfere with one’s sleep. More importantly, pregnant and lactating women must limit their green tea intake as it may pass into breast milk and cause insomnia in nursing infants.

5. Irregular Heartbeat

It’s caffeine, again. Caffeine is known to stimulate the heart as well. It causes your heart rate to speed up, causing irregularly fast heartbeat – a condition called tachycardia. This condition can make you feel as if your heart is pounding in your chest.

6. Vomiting

As per one Indian study, green tea polyphenols can, in fact, cause oxidative stress. And excessive intake of caffeine, including that from green tea, can trigger nausea and vomiting.

7. Diarrhea

Diarrhea could occur if you are new to green tea. Loose stools could be one of the mild side effects (due to the caffeine content), which can eventually subside as you get used to the beverage.

8. Muscle Tremors And Contractions

Excessive caffeine consumption has also been linked to muscle spasms and twitching. And individuals with an abnormal sinus rhythm must limit caffeine intake.

9. Heartburn

Green tea is acidic, and hence can irritate the esophageal lining, causing acid reflux or heartburn. The condition could get worse if an individual is already suffering from heartburn (or acid reflux).

10. Dizziness

 It has been found that long-term caffeine dosages of above 1.5 grams per day can lead to certain non-specific symptoms, a couple of them including vertigo and dizziness.

11. Tinnitus (Ringing In The Ears)

According to the American Tinnitus Association, beverages that contain caffeine are known to aggravate tinnitus. Green tea, being a source of caffeine, can lead to the condition.

 12. Convulsions

According to one study, green tea extract was found to significantly accelerate the onset of convulsions in the mice that were tested upon. The tea had always increased the duration of the convulsions.

Also, green tea might keep folic acid from working the way it must. This can lead to a condition quite similar to folic acid deficiency.

13. Bleeding Disorders

Caffeine in green tea can increase the risk of bleeding. Which is why you must stay away from it if you have any bleeding disorder.

According to the University of Maryland Medical Center, green tea, when mixed with aspirin, might prevent the blood from clotting. Using the two at a time can increase your risk of bleeding.

14. Diabetes

Though there are studies that have highlighted the benefits of green tea for diabetes, there are studies that state otherwise too. A small number of studies using green tea, the extract, and catechins (the main ingredient in green tea) only showed disappointing results in treating Type 2 diabetes. The same results occurred when it came to protecting healthy individuals from the disease.

15. Glaucoma

Black tea contains caffeine. And so does green tea. But when one uses the two together, the risk of caffeine side effects just multiplies. Drinking the tea drastically increases the pressure in the eye. This occurs within 30 minutes of drinking the tea and lasts as long as 90 minutes.

16. High Blood Pressure

The flavonoids in green tea that are touted to be healthy (which they are) are absorbed by the body at a rapid rate. This, along with the caffeine content in the tea, might lead to a sudden (but temporary) rise in blood pressure levels. Numerous studies have found green tea to elevate blood pressure levels. Though the rise in the levels doesn’t raise any health concerns, one thing is clear – green tea may not be the safest or the most dependable way to regulate blood pressure levels.

17. Liver Disease

Nowadays, green tea extracts are vigorously marketed as weight loss supplements. Though there is little evidence supporting the efficacy of green tea in this aspect, certain serious side effects, including acute liver failure, are being reported. As per a New York study, green tea extract is one of the many herbal and dietary supplements associated with liver abrasion.

The catechins in green tea deliver huge benefits like lowered cholesterol and reduced risk of cancer and cardiovascular disease. But if taken in high doses, especially similar to the dosage in weight loss supplements, these catechins cause liver toxicity.


18. Osteoporosis

Caffeine has been found to inhibit calcium absorption. It can also increase the rate of calcium excretion in the body. This results in a leaching effect on calcium levels in the bones, although only temporarily. But with extended consumption, this could lead to bone diseases like osteoporosis.


19. Skin Allergies

The commonest allergies associated with green tea consumption are eczema and hives. An individual can also experience a tingling sensation on the face, lips, tongue, or in the throat.

20. Kidney Issues

A review of studies has proven that the very polyphenols that are credited with preventing cancer and heart disease can also cause kidney damage if taken in excessive quantities. As per experts, people consuming green tea supplements must exercise caution, in particular.

21. Issues With The Thyroid Gland

Studies have suggested that the catechins in green tea might affect the functioning of the thyroid gland. As per one study published in 2013, catechins can disrupt thyroid function and block the production of hormones. This can also lead to the enlargement of the thyroid glands. Hence, if you already are on thyroid medication, take your doctor’s advice on green tea intake.

22. Frequent Urination

The caffeine in green tea also acts as a natural diuretic. As per reports, keeping green tea intake within 5 cups per day (or 200 to 300 mg of caffeine per day) can be one solution.

Green tea is also one of those beverages that can aggravate the bladder. This is especially true if the individual is suffering from a urinary tract infection. In such an eventuality, they must avoid green tea (or any form of caffeine) and drink plenty of water instead.

23. Fertility

One study states that consuming green tea too often can lower fertility. In the study, embryos and larvae subjected to smaller doses of green tea were slower to develop. They also showed a decline in their ability to produce offspring.


24. Teeth

One of the major bad effects of drinking green tea, or green tea in this context, with respect to teeth is it contains tannins. And two, it is its acidic nature. These two factors cause the tea to stain your teeth.

Another downside is what we have seen with calcium – caffeine in green tea can slow down the absorption of calcium, weakening teeth or limiting their growth.







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