Matcha is a vibrant green powder made from finely ground, shade-grown green tea leaves. This preparation method, where the entire leaf is whisked into a beverage and consumed, is why matcha delivers a potent concentration of beneficial compounds. Consuming the whole leaf material results in a significantly higher dose of active ingredients compared to traditional steeped tea. This higher concentration raises the potential for overconsumption, necessitating a careful consideration of safety.
Symptoms of Excessive Caffeine Consumption
The most immediate issue arising from overconsumption is related to matcha’s high caffeine content. An average serving (one teaspoon or two grams of powder) contains 40 to 80 milligrams of caffeine. Consuming multiple servings can quickly push an individual past the generally accepted daily limit of 400 milligrams of caffeine for a healthy adult.
Exceeding this limit often leads to uncomfortable physiological responses known as “caffeine intoxication.” Symptoms include noticeable jitters, anxiety, and restlessness, resulting from central nervous system overstimulation. Excessive intake can also trigger cardiovascular effects, such as an accelerated heart rate or heart palpitations.
Caffeine also interferes with normal sleep patterns, frequently causing insomnia or reduced sleep quality when consumed too close to bedtime. Furthermore, it increases stomach acid, which can lead to digestive upset, nausea, or diarrhea. While matcha contains the amino acid L-theanine, which promotes calm focus, it does not neutralize the total milligram dose of caffeine.
EGCG and Potential Liver Stress
A distinct concern is the potential risk associated with the high concentration of Epigallocatechin Gallate (EGCG) in matcha. EGCG is the primary catechin, an antioxidant responsible for many of green tea’s health benefits. A single serving delivers a large dose of EGCG, often between 100 and 220 milligrams.
The worry about EGCG is linked primarily to highly concentrated green tea extract supplements, not the traditional beverage. Cases of elevated liver enzymes and, in rare instances, liver injury have been reported in people taking extremely high doses. The European Food Safety Authority indicates that a daily intake above 800 milligrams may show initial signs of adverse liver effects.
Drinking matcha makes it highly unlikely to reach this threshold, as it requires consuming four or more very strong servings daily. Consuming catechins on an empty stomach may increase EGCG bioavailability, potentially increasing the risk of an adverse reaction. Those with pre-existing liver conditions or who are taking green tea supplements should exercise caution.
Heavy Metal Risk in Matcha
Tea plants naturally absorb elements from the soil and environment, including heavy metals like lead and cadmium. In traditional steeped tea, the leaves are discarded after brewing, and only a small fraction of these metals transfers into the water.
Because the entire powdered leaf is consumed with matcha, exposure to heavy metals is significantly higher than with steeped tea. Lead is the most commonly cited element of concern, as tea plants are known accumulators of this metal.
Mitigating this risk requires careful sourcing and quality control. High-quality matcha, particularly ceremonial-grade products, often undergoes rigorous testing for heavy metals. Consumers should look for brands that provide independent lab results confirming that levels are well below international safety limits.
Establishing Safe Daily Servings
Based on the cumulative risks, a healthy adult should limit intake to a moderate range. Considering the 400-milligram daily caffeine limit and potential EGCG stress, consuming between two and four standard servings of matcha per day is recommended. A standard serving is defined as one teaspoon (two grams) of powder.
To minimize potential issues, avoid consuming matcha late in the afternoon or evening to prevent sleep disruption. It is also beneficial to consume matcha with or after a light meal, rather than on an empty stomach, to reduce EGCG bioavailability and minimize digestive discomfort.