The world has witnessed a surge in popularity for the Japanese matcha drink, thanks to its health reputation, particularly due to its caffeine and antioxidant content.
Matcha Hides a Side Effect That Concerns Doctors
Despite its benefits, nutrition experts warn that excessive consumption may hinder iron absorption and increase the risk of anemia, especially among vegetarians.
Matcha is prepared from the leaves of the green tea plant (Camellia sinensis), which are ground into a fine powder. Because these leaves are grown in the shade, they produce higher levels of chlorophyll, giving them their dark green color and enhancing their nutritional content.
Rob Hobson, a nutritionist and author of *Unprocess Your Family Life*, explains that matcha is rich in polyphenols, antioxidant compounds that reduce inflammation and protect against chronic diseases. It also contains caffeine, which enhances focus, along with L-theanine, a compound that mitigates the excessive stimulating effects of caffeine.
But these same beneficial compounds, such as catechins and tannins, may reduce the absorption of non-heme iron found in plant-based foods like lentils, tofu, and leafy greens.
Professor Gunter Kuhnle, a nutrition professor at the University of Reading, says that matcha binds to iron in the digestive tract and prevents its absorption. He notes that this can reduce the body's iron utilization by up to 50%, although this percentage varies from person to person and depends on the timing of the meal and the type of food consumed.
Kühnle added that regular green tea has the same effect, citing a rare case of a 48-year-old man who developed anemia as a result of excessive matcha consumption.
Despite this, Hobson emphasizes that moderate matcha consumption poses no risk to those following a balanced diet. However, he cautions that vegetarians are more susceptible because they rely on plant-based sources of iron, which are more affected by these compounds.
He advised: "If you rely on plant-based sources of iron, such as lentils, tofu, or leafy greens, it's best to avoid drinking matcha with meals, as it may impair iron absorption in the intestines."
He also stressed the importance of not taking iron supplements at the same time as drinking matcha, especially for those already suffering from iron deficiency.
It's worth noting that iron deficiency (or anemia) is characterized by common symptoms such as fatigue, pale skin, shortness of breath, headaches, and heart palpitations, according to the UK's National Health Service (NHS).
A study from Lund University in Sweden showed that anemia is common among teenage girls and vegetarians, with 38% of female participants and 70% of vegetarians suffering from iron deficiency.
To avoid this risk without giving up matcha, experts advise against drinking it with meals and recommend avoiding additions such as cream or sweetened syrups. It's best to consume it simply to reap its benefits without negatively impacting iron absorption.