Matcha side effects: How overconsumption can affect liver and digestion

Matcha, a finely ground powder made from green tea leaves, is celebrated for its antioxidants, calming L-theanine, and sustained energy boost. While moderate intake offers benefits like improved focus, better metabolism, and heart health support, excessive consumption can pose health risks. Too much matcha may lead to digestive issues, anxiety, rapid heartbeat, and disrupted sleep due to its high caffeine content. It can also increase the risk of iron absorption problems and kidney stones when consumed in excess. Being mindful of portion sizes and timing is essential to enjoy matcha’s benefits without compromising your health. Moderation remains the key.



Health risks of overconsumption of matcha
A comprehensive review in Current Research in Food Science examined matcha’s therapeutic potential, highlighting its rich profile of catechins, caffeine, L-theanine, and chlorophyll, which may support cognitive, cardiovascular, metabolic, and anti-tumour health. However, the authors emphasise that these potent compounds warrant careful dosing. Excessive intake, especially of concentrated extracts or supplements, may heighten the risk of side effects such as oxidative stress, impaired liver function, or nutrient imbalances.


1. Caffeine overload: Anxiety, jitters, and sleep issues

Matcha contains significantly more caffeine than regular green tea, with about 70 mg per cup. While this can provide a natural energy boost, excessive intake may overstimulate the nervous system, leading to symptoms such as anxiety, nervousness, and a rapid heartbeat. These effects can be more pronounced in individuals sensitive to caffeine or those who consume multiple cups in a day.


2. Restlessness and poor sleep quality

Restlessness and poor sleep quality are common issues linked to excess matcha intake. Its high caffeine content can disrupt your sleep cycle, making it harder to fall asleep and stay asleep. Over time, this may lead to fatigue and reduced energy during the day. To avoid this, it’s best to limit matcha consumption to the morning or early afternoon.


3. Digestive discomfort and stomach upset

Matcha is rich in tannins and catechins, compounds that can irritate the stomach lining if consumed in large amounts or on an empty stomach. This may result in:
Nausea
Cramps
Diarrhoea or constipation
If you have a sensitive stomach, it’s best to drink matcha with food.


4. Reduced mineral absorption

High amounts of tannins in matcha can interfere with the absorption of essential minerals such as iron and calcium. Over time, this could contribute to nutrient deficiencies, especially in individuals with plant-based diets or those already prone to low iron levels.


5. Potential liver concerns

Excessive intake of catechins, especially from concentrated sources, may affect liver health. Though rare, cases have been linked to overconsumption of green tea extracts, so moderation is essential to prevent potential liver toxicity and maintain overall metabolic balance in the body.



Other risks you should know
Aside from the major concerns, drinking too much matcha can also pose other health risks:

• Hormonal imbalance: High caffeine intake may increase cortisol levels, the stress hormone, contributing to fatigue, anxiety, and mood swings.
• Kidney stone risk: Matcha contains oxalates, which in excess can contribute to the formation of kidney stones.
• Contaminants in low-quality matcha: Cheap or poorly sourced matcha may contain heavy metals or pesticides. Always choose high-quality, organic brands to reduce these risks.

How matcha is safe

For most adults, 1–2 cups per day (about 2 g of matcha powder) is considered safe. To minimise risks:

• Keep total daily caffeine intake under 400 mg.
• Choose organic, high-quality matcha to avoid contaminants.
• Avoid drinking matcha on an empty stomach.
• If you have any medical conditions or take medication, consult your doctor first.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making any changes to your health routine or treatment.




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