Matcha is a finely ground powder made from specially grown and processed green tea leaves. Unlike traditional green tea, where the leaves are steeped and then discarded, drinking matcha involves ingesting the entire leaf material suspended in liquid. This unique method delivers a much higher concentration of the tea’s natural compounds, including both beneficial antioxidants and potentially problematic substances. While generally safe for most people, this high concentration means certain individuals should exercise caution or avoid the beverage completely due to its potent chemical profile.
Sensitivity to High Caffeine Levels
The caffeine content in matcha is significantly elevated compared to regular steeped tea. A typical serving (two grams of powder) can contain between 60 and 80 milligrams of caffeine, often double the amount found in standard brewed green tea.
People with pre-existing heart conditions, such as tachycardia or arrhythmias, may find that this higher caffeine dose triggers an increased heart rate or palpitations. Similarly, those who struggle with severe anxiety disorders or panic attacks should be cautious, as caffeine is known to exacerbate feelings of nervousness, restlessness, and jitteriness.
Even in healthy individuals, consuming matcha later in the day can severely disrupt sleep patterns. Individuals suffering from chronic insomnia or other sleep disorders should avoid matcha in the afternoon, as the stimulating effects can linger for several hours. Although matcha contains L-theanine, an amino acid that promotes focused alertness, this compound only moderates the caffeine experience and does not eliminate the stimulant from the system.
Gastrointestinal and Nutrient Absorption Concerns
The non-caffeine chemical components in matcha can pose problems for people with sensitive digestive systems or specific nutritional deficiencies. Matcha is rich in tannins and catechins, which are polyphenolic compounds. While these compounds are beneficial, they can irritate the digestive tract, especially when consumed on an empty stomach.
Individuals managing Gastroesophageal Reflux Disease (GERD) or gastritis may experience a flare-up of symptoms, as the high concentration of components can stimulate stomach acid production. Although matcha is less acidic than coffee, its stimulating effect can relax the lower esophageal sphincter, allowing stomach acid to back up into the esophagus. Consuming matcha with a meal or diluting it significantly can help mitigate this irritating effect on the stomach lining.
These polyphenols interfere with the body’s absorption of iron. Tannins bind to non-heme iron, the type of iron found in plant-based foods, making it unavailable for the body to absorb. Individuals with Iron Deficiency Anemia, particularly those who follow vegetarian or vegan diets, should be mindful of this effect. To minimize interference, consume matcha at least one to two hours away from iron-rich meals or supplements.
Specific Considerations for Pregnancy and Nursing
The consumption of concentrated substances like matcha during pregnancy and nursing requires careful consideration. The primary concern during pregnancy is ensuring that total daily caffeine intake remains below the recommended limit of 200 milligrams, as caffeine crosses the placenta and can affect the developing fetus. Given matcha’s higher caffeine concentration, a single large serving could quickly approach this limit, especially if other caffeine sources are consumed.
The compounds in green tea that inhibit iron absorption may also interfere with the metabolism of folate, a nutrient important during the early stages of pregnancy. The whole-leaf consumption method also amplifies the potential for contaminants to pass to the fetus or infant. While moderate amounts of high-quality matcha may be acceptable, a healthcare provider must approve any regular consumption due to the lack of extensive safety data.
The Danger of Poor Quality Sourcing
A risk factor unique to matcha consumption is the potential for ingesting contaminants present in the tea plant itself. Unlike traditional green tea where the leaves are steeped and discarded, consuming the entire leaf powder means any substances the plant has absorbed from its environment are consumed directly.
Tea plants readily absorb heavy metals, such as lead, cadmium, and arsenic, from the soil and air. If the tea is grown in contaminated soil or a region with high air pollution, these metals become part of the final powder. Low-quality or non-certified matcha may also contain residues from pesticides used during cultivation. Consumers seeking to avoid these risks should exclusively purchase high-grade, certified organic matcha from reputable sources that provide evidence of third-party testing for heavy metals and pesticides.