Matcha green tea is a healthy drink commonly consumed in China and Japan that has also become popular in other parts of the world due to its many health benefits.
Although reputed to relieve digestive symptoms, little is still known about matcha’s possible side effects on the digestive system. In this post, we will investigate how matcha tea negatively affects digestion and how it could cause constipation.
Compounds in matcha tea that affect digestion
Matcha green tea is a green, fine powder obtained from the ground leaves of the Camellia sinensis plant. It is generally considered safe to use as research shows that it is a strong antioxidant and anti-inflammatory with the potential to treat degenerative, cardiovascular, cancerogenic, body weight, and digestive disorders.
Its chemical composition consists of polyphenols, minerals, amino acids, and caffeine, amongst which epigallocatechin gallate (EGCG), l-theanine, potassium, iron, calcium, and caffeine (2-4%) are the main compounds.
However, some of the compounds present in this healing tea, when consumed in excess can cause several issues.
Matcha tea usually contains around 30 to 70 mg of caffeine per 6 to 8 oz. cup, which is much less than a cup of coffee. But due to overconsumption, especially for weight loss purposes, the caffeine dosage may end up triggering laxative effect and exacerbate pre-existing conditions such as irritable bowel syndrome. It can also be problematic for digestion as excess consumption can lead to nausea, vomiting, diarrhoea, headache, and loss of appetite. It can equally cause an increase in urine output which in turn can lead to dehydration.
Epigallocatechin gallate (EGCG)
Epigallocatechin gallate (EGCG) is a polyphenol found in matcha tea known to have antioxidant and anti-inflammatory properties. However, when matcha tea is brewed at high temperatures or consumed on an empty stomach, this polyphenol tends to cause stomach irritations upon consumption. Ideally, this tea should be prepared using water with a temperature between 60°C to 80°C.
This study revealed that when green tea is consumed in high doses (i.e. 5–6 litres/day) it causes nausea, spitting, stomach bloating/ache, dyspepsia, flatulence, and diarrhoea. Although it is very unlikely anybody would consume that much green tea in a day, however, as matcha green tea is a much more concentrated version of green tea you won’t have to drink that much matcha before you get those side effects.
Can matcha green tea cause constipation?
When taken in small doses, green tea can help facilitate bowel movements, and act as a relief for constipation.
However, too much caffeine causes dehydration and forces the colon to pull extra water from the stool, which may leave you with some uncomfortable hard stool texture.
Matcha tea also contains tannins and when over-consumed, these can lead to the malabsorption of iron by the body. As a result, this can cause iron deficiency anaemia, usually linked to various gastrointestinal conditions.
To avoid these side effects, consume green tea moderately and no more than 1-2 cups of matcha a day.
If you love green tea but are sensitive to caffeine, try drinking decaffeinated tea. Decaf matcha tea contains only 2ml of caffeine which is less likely to cause indigestions. If you already suffer from conditions that put you at risk of this tea’s side effects, make sure you consult your doctor before drinking green tea.