Can green tea cause heartburn?

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Green tea has several health benefits, but those who have heartburn after caffeine intake might want to stay away from it.

What is green tea?

Grren tea

Green tea is a traditional Chinese herbal tea made from the leaves and buds of the Camellia sinensis plant.

Unlike black tea and oolong tea, green is not oxidized and is often referred to as unfermented or non-fermented tea.

Generally, after the leaves are harvested, sun-dried briefly or steamed, heated, rolled into different shapes, dried, and packaged. The steaming time can be varied to produce different kinds of green tea.

For example, in Japan, steaming is done for 30-90 seconds to produce Sencha tea and for 90 -150 seconds to produce Fukamushi tea.

The color of brewed green tea varies from green to yellow to light brown and should be mildly astringent in taste.

Some of the popular varieties of green teas are:

  • matcha
  • mint green tea
  • Jasmine green tea
  • sencha and fukamushi sencha

The benefits of drinking green tea

About 90% of green tea is composed of polyphenols, amongst which catechins (such as epigallocatechin gallate – EGCG) and flavanols (such as chlorogenic acid) are the major components.

Other components present in smaller quantities are:

  • amino acids (about 7%)
  • caffeine
  • proanthocyanidins and theanine (about 3%)

These substances show several anti-inflammatory and antioxidant activities which account for the various health benefits of green tea.

Neuroprotective benefits

Green tea polyphenols scavenge free radicals such as reactive oxide species (ROS) and reactive nitrogen species (RNS) which oxidize brain cells.

This can protect from mitochondria dysfunction and cell death which can result in neurodegenerative diseases like multiple sclerosis, Alzheimer’s disease, and Parkinson’s disease.

Weight loss benefits

The catechins present in green tea accelerate thermogenesis and fat oxidation by inhibiting the enzyme catechol O-methyl-transferase (COMT) that degrades norepinephrine. Thermogenesis is the process of dissipating energy via the production of heat in specialized tissues like adipose tissues and skeletal muscle.

Green tea also contains some caffeine, and caffeine has been proven to boost metabolic rates as well. The combined effect of catechins and caffeine thus makes green tea a good weight loss beverage.

Brain function benefits

Green tea contains caffeine, which is a well-known neurostimulator, that blocks the inhibitory neurotransmitter adenosine, and increases the concentration of neurotransmitters like dopamine and norepinephrine.

This improves various aspects of brain function such as mood, memory retention, reaction time, and vigilance.

Green tea also contains the amino acid l-theanine which increases the activity of GABA (gamma-aminobutyric acid), an inhibitory neurotransmitter with anti-anxiety effects.

Caffeine works in synergy with L-theanine producing a more powerful effect in improving brain function.

Is green tea acidic or alkaline?

Green tea has a pH range of 7 to 10, with 7 being a neutral pH, and 10 being alkaline. So, it is more of a neutral to an alkaline tea, than an acidic tea which is characterized by lower pH ranges (less than 7).

This is also one of the reasons green tea powder is sometimes used in the manufacture of dentifrices, which are typically alkaline (pH 7 to 10) as acidity destroys the enamel of the teeth.

Is green tea good for acid reflux?

Is Green Tea Good for Acid Reflux? or Bad for Acid Reflux?
A short video about green tea and acid reflux. Duration: 2:55.

Green tea has several health benefits that might prevent or relieve acid reflux symptoms:


The phenolic compounds present in green tea have anti-inflammatory properties, as such reducing swelling and irritation of the esophagus walls, relieving heartburn.

Tannins, for instance, form a protective layer over injured epithelial cells in inflammation, permitting natural healing to occur underneath.

EGCG on the other hand acts by inhibiting pro-inflammatory mediators, like tumor necrosis factor alpha.

Esophagitis has been linked to inflammation which can be caused by oxidative stress and some of the phenolic compounds in green tea like flavanols and EGCG, are potent antioxidants that sequester free radicals that cause oxidative stress and damage cells.

Moreover, these antioxidants promote appropriate digestion and contraction of the lower esophageal sphincter, preventing reflux and consequently heartburn.

Calms the nervous system

Green tea is known to calm nerves and increase relaxation which can help relieve heartburn in people suffering from heartburn.

Stress and anxiety can create long-lasting tension in the stomach muscles, increasing the pressure in the stomach which can push up acid into the esophagus.

High stress levels stimulate the elevation of acetylcholine (a neurotransmitter) and histamine levels, which increase the quantity of acid produced in the stomach, worsening reflux and heartburn.

Prevent stomach acid flow back

The amino acid L-theanine has been reported to prevent relaxation of the lower esophageal sphincter, which causes food to flow back into the esophagus and cause heartburn.

L-theanine acts as gamma-aminobutyric acid (GABA) agonist after it’s ingested. An increase in GABA receptor activity also increases the lower esophageal tone and decreases the relaxations of the lower esophageal sphincter.

The Food and Drug Administration (FDA) has classified L-theanine as “generally recognized as safe” (GRAS) and it has been incorporated into food products and dietary supplements and successfully used in the treatment of heartburn.

Consuming between 100mg to 200mg of theanine supplements, two to three times a day for a couple of days has been reported to treat symptoms of moderate to severe GERD (gastroesophageal reflux disease).

Can green tea trigger acid reflux?

As mentioned above, green tea might be beneficial for acid reflux sufferers for several reasons, however, some people do experience heartburn after drinking green tea.

The most common culprits are drinking too much tea and sensitivity to one of the components of the tea.


Excessive consumption of green may not be good for the health particularly because of its caffeine content.

Caffeine can upset the stomach and cause irritations which can trigger acid reflux and heartburn in sensitive patients.


While tannins are beneficial in small amounts, too much of them can stimulate the production of gastric acid, increasing the amount of stomach acid that flows back to the esophagus.

Is green tea good for the digestive system?

One of the popular benefits of green tea is its benefit to the digestive system:

Green tea’s ability to enhance a healthy gut microbiome is crucial for maintaining overall well-being because it helps fight harmful bacteria as well as protects against inflammatory diseases.

Side effects of (too much) green tea

Generally, drinking about 8 cups of green tea per day is considered safe, and at most 6 cups per day for pregnant women (at most 200mg of caffeine).

Drinking more than that might trigger symptoms. Those who are sensitive to caffeine might experience symptoms even after drinking a few cups.

Can trigger acid reflux

As mentioned above, due to its caffeine and tannin content, too much green tea might cause symptoms for people who are suffering from GERD or prone to acid reflux.

Possible liver injury

Excessive drinking of green tea has been associated with liver injury because of excess consumption of catechins. This is a rare situation though, and the cases seen so far have been with people who consumed green tea extracts which have catechins in concentrated amounts.

Interference with medications

Furthermore, excessive drinking of green tea can interfere with certain medications such as certain antibiotics, beta-blockers, statins, and chemotherapy medications. Therefore, it is advised that people do not take such medications alongside dietary supplements like green tea extracts.

Possible negative effects in infants

Drinking too much green tea during pregnancy can increase the risk of birth defects for children linked with a deficiency in folic acid.

Moreso, excess consumption of green tea during breastfeeding can affect the infant as caffeine crosses into breastmilk. Caffeine may cause certain reactions in babies like poor sleeping patterns, irritability, wakefulness, and fussiness.

Final thoughts

Green tea is one of the most popular teas consumed in the world today due to its numerous health benefits. However, consumption should be done moderately because excessive consumption can cause health problems.

While green tea has many beneficial properties to relieve heartburn, it might still be a trigger for some people.

Drinking too much and sensitivity to caffeine are the most common causes of experiencing heartburn after green tea intake. In such cases, go for the decaffeinated green tea option, which is less likely to trigger symptoms.

This article has been written by:

Meggy Jones

Expert Nutritionist and Food Scientist,
M.Sc. – Nutrition, ugent, Belgium