As matcha lattes surge in popularity across Thailand and beyond, new research and expert warnings are emerging about a hidden downside to the green drink’s health halo: a potential risk of iron deficiency, especially among vegetarians and plant-based eaters. Nutritionists interviewed in a recent report by The Independent explain that while matcha is rich in antioxidants and confers several metabolic benefits, overconsumption—or pairing it unwisely with certain foods—may be contributing to lower iron levels in some individuals. This news is particularly relevant to Thai readers, given the national shift toward novel health foods and the rising appeal of Japanese tea culture in Bangkok and major cities.
Thailand’s fascination with matcha, imported from the Japanese tradition, has exploded in recent years. Cafés from Chiang Mai to Phuket now offer matcha lattes and desserts, touting their antioxidant-rich properties and bright green color. Many health-conscious consumers are drawn to the drink’s reputation for boosting mental alertness, reducing inflammation, and protecting against chronic disease, as confirmed by nutritionist and author Rob Hobson. “It contains polyphenols which protect the body against oxidative damage,” Hobson notes, adding that the presence of L-theanine helps mellow the effects of caffeine for a balanced and focused energy (The Independent).
Yet, these same polyphenols—catechins and tannins, found in high concentrations in matcha—are also the culprit behind matcha’s impact on iron absorption. Professor Gunter Kuhnle, a leading nutrition and food science researcher from the University of Reading, explains that polyphenols in matcha bind to non-haem iron (the form found in lentils, leafy greens, tofu, and many plant foods), preventing it from being effectively absorbed by the gut. “These complexes then pass through the gut and are not useful for the body—this can reduce iron uptake by up to 50 percent,” he points out. The effect is less pronounced with haem iron found in animal sources such as red meat, which is not as easily bound and blocked by polyphenols.
This raises particular concerns for Thai vegetarians and vegans, as well as teenage girls—a group already prone to lower iron levels. According to a recent Swedish study cited by The Independent, among adolescent girls and plant-based eaters, almost 40% and 70% respectively were found to be affected by iron deficiency (The Independent). The British National Health Service warns that the symptoms of anaemia due to low iron may include fatigue, headaches, paleness, shortness of breath, and heart palpitations (NHS). For Thais, especially in urban centers where meat-free diets and matcha-based drinks are both trending, this emerging research is especially relevant.
Experts stress that for those consuming a well-rounded Thai diet—including fish, poultry, and even organ meats commonly found in traditional dishes—the risk of matcha-induced iron deficiency is likely limited. Notably, if you do not experience symptoms and consume a variety of iron-rich foods, moderate matcha consumption remains a healthy choice. However, nutritionists warn that individuals who rely heavily on plant-based iron sources should avoid drinking matcha or green tea with their main meals. The advice extends to those taking iron supplements: “Do not take your supplement with matcha, green tea, or even black tea,” says Hobson, as the polyphenols can severely limit the supplement’s effectiveness.
In Thai culture, where communal eating is common and hot drinks may be enjoyed alongside meals, this guidance calls for some dietary reconsideration. A public health nutritionist from a leading Thai university remarks: “With the increasing popularity of plant-based diets in Thailand’s educated urban classes, and the embrace of international beverages such as matcha, people need to be aware of how timing can affect nutrient absorption.” The consensus among nutritionists is to drink matcha either between meals or as a mid-morning/afternoon beverage, rather than as a companion to food. This recommendation aligns with findings from several global studies on polyphenol-iron interactions (PubMed).
Thailand’s own food culture, with its herbal teas (like bai bua bok and roselle), traditional desserts such as “khanom thuay” (made with coconut milk, not rich in iron), and rising coffee and tea consumption, offers ample opportunity for individuals to vary beverage choices. Historically, the Thai diet provided sufficient iron through frequent consumption of offal and seafood. However, as Western and Japanese dietary influences become more dominant, eating patterns have shifted, and awareness of micronutrient interactions becomes more critical.
Looking forward, health professionals expect the popularity of matcha and specialty teas to remain strong, but anticipate increased educational efforts about their nutritional impacts. Consumer awareness campaigns by the Thai Ministry of Public Health could help address this by including guidance on beverage consumption alongside iron-rich meals, especially targeted at teenagers and young women. Nutritionists also suggest experimenting with different drink timings or opting for plain matcha without added sweet syrups or cream to maximize its health benefits.
The latest research further encourages Thais to continue enjoying matcha but with sensible timing and moderation. Those following vegetarian or vegan diets should be especially mindful. If you experience symptoms of iron deficiency, consult with a healthcare provider and consider blood tests to check ferritin and hemoglobin levels. For now, the healthiest way to embrace matcha is to relish it between meals—delivering both its unique flavor and antioxidant benefit without compromising on essential nutrients.
For more information, refer to the original article by The Independent, the NHS, and published studies on the topic (The Independent; NHS Iron Deficiency; PubMed on Tea and Iron).