Is Drinking Too Much Green Tea Bad for You?

October 28, 2018

Is Drinking Too Much Green Tea Bad for You?

Green tea is high in antioxidants and provides other health benefits. For that reason, many people have begun drinking green tea instead of coffee or cola to get their caffeine boost.

However, as with many health-giving products, it can be consumed in high levels that can cause unpleasant, and possibly even dangerous side effects. If you imbibe more than five cups of green tea per day, you may begin to experience some of these side effects.


Keep reading to discover more about the side effects of consuming too much green tea. 

How I Started My Research About this Topic

Last month, a customer asked me this question. 

Is drinking too much green tea bad for me?

Since I knew very well about caffeine from my earlier research and article I wrote, I told the customer about disadvantage of caffeine during the call. 

After that I thought I should see if there are other effect by drinking too much green tea. 

As I research more, I find out some negative effects.  I almost stopped writing about the article once as you know I promote about healthy green tea and I am drinking green tea because it makes me feel better and healthy. But I thought it is important to write about this and being honest to you. 

As a green tea lover, this article was really hard to write, but I wanted to be true to the facts and the science.  

This article is not my favorite one as a result, but gives you important information about green tea when drink excessively. 

Too Much Caffeine is Not a Good Thing

While green tea has health benefits, it is also a caffeinated beverage. An excess of caffeine can cause such side effects as:

  • An increase in heart rate
  • An upset stomach
  • Anxiety (if you are already prone to anxiousness, please monitor your green tea consumption) 
  • Restlessness (an excess of green tea may make you feel restless and make it hard for you to relax)
  • Tremors (along with restlessness, your hands or other parts of your body may shake if you drink too much green tea) 
  • Insomnia (the caffeine in green tea works just like the caffeine in soda or coffee, so, if you drink too much green tea or it too late in the day, you may have problems sleeping) 
  • If you routinely drink green tea and suddenly stop, you might experience caffeine withdrawal symptoms which include irritability, drowsiness, and headaches

 The caffeine levels in green tea may vary. For an exact amount of caffeine in your favorite green tea product, please check the label on the packaging.

However, most major brands of green tea contain approximately 35 milligrams of caffeine per tea bag when brewed. Drinking between 200 and 300 milligrams of caffeine per day has been considered by some to be useful, but less caffeine may have stronger side effects for some sensitive people.

I have written a comprehensive article about green tea and caffeine.  Click here to read my other article : Green Tea Science : Caffeine - Everything you need to know (and more) about Caffeine and Green Tea

Too much green tea

Impaired Iron Absorption Due to Green Tea

One of the antioxidants in green tea is flavonoids which also have their own important health benefits. Consuming lots of foods and drinks like green tea which contain flavonoid also allows the body to consume nonheme iron.

This is also found in food plants like beans, vegetables, and fruit. However, once the flavonoids bond to the iron in these foods, the body can’t absorb or use them.

So, if you drink green tea with a meal, you might want to consider drinking it at a different time of day. The more green tea that you drink with a meal, the less iron will absorb from your food into your bloodstream and your body.

Adding a little lemon to your green tea may help prevent the flavonoids from binding to the iron in your diet. So, if you have to have green tea with a meal, squeeze some lemon into your cup.

The Not-So-Sweet Results of Drinking Sweet Tea

If you buy your green tea in a bottle or use a large amount of sugar or honey when you make your green tea, you are adding many unwanted calories to your daily calorie intake number, which, in turn, may cause you may gain unwanted weight. Plain green tea is calorie free, but again, look out for bottled green tea, which is frequently sweetened with sugar, adding to the health problems of obesity and diabetes.

Drinking Green Tea During Pregnancy Could Harm Your Baby

Drinking a lot of green tea, defined as more than three cups a day, can block your body's ability to absorb folic acid. The tannins in green tea can prevent your body from being able to process this important nutrient.

Folic acid protects against birth defects and pregnant women are advised to increase their intake of it. It is estimated that folic acid supplementation can lower the risk of spina bifida and other neural conditions by 70 percent.

If you're pregnant, you should limit your consumption of green tea or skip it entirely.

Could My Green Tea Consumption Cause Medical Problems?

Generally, drinking a little green tea is safe for most people. Drinking too much green tea irritates some already existing medical problems. If you already combat anxiety, drinking more than a cup or so of green tea may increase your anxiety levels.

If you have a medical condition that includes diarrhea, drinking green tea will increase the amount of diarrhea you have. Also, people with specific conditions shouldn’t drink any green tea. Some of these conditions include:

  • Bleeding disorders
  • Anemia
  • Glaucoma
  • Heart conditions
  • Bleeding disorders
  • Any liver condition
  • Anxiety
  • Diarrhea and other gastric disorders
  • Depression

If you have one or more of these health disorders, please discuss drinking green tea with your healthcare provider to see if green tea consumption is safe for you.

As with many aspects of life, green tea may be safe for you as long as you don’t overindulge. However, if you have sensitivity issues with caffeine products or if you drink a significant amount of green tea, you should cut back and talk to your doctor before continuing your green tea consumption.


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