Britany Kasjak knew something was off with her body when she suddenly felt sluggish and noticed her hair was thinning.
Kasjak, a Toronto-based natural wellness and holistic health content creator, said she believes the changes were sparked by how her body was responding to the daily matcha drinks she began having with meals.
She said she went down an online “rabbit hole” after her friends approached her with a similar problem, leading her to question whether the source of her and her friends’ symptoms was somehow related to her new favourite beverage.
Matcha has seen a global surge in popularity in the last few years, making it a popular choice among Gen Z, health and wellness influencers, and celebrities for its potential health benefits, taste, and esthetic green colour.
At the same time, the finely ground traditional Japanese green tea powder — which is used in a variety of types of foods and beverages such as hot and cold lattes — is facing a global shortage and rising prices due to the skyrocketing demand.
Although rich in antioxidants, experts say matcha could hinder the body’s iron absorption and possibly cause a deficiency in those with pre-existing iron-related conditions and anemia.
Here’s what you need to know.
Can matcha cause iron absorption problems?
Matcha contains tannins, a polyphenol compound found naturally in numerous plant-based foods, that can interfere with iron absorption in our bodies.
There are two types of iron — non-heme iron found in plant-based foods and heme iron from animal sources.
Tannins can temporarily hinder iron absorption by binding to non-heme iron, forming compounds that aren’t easily absorbed in the intestines and are instead excreted, said Sarah Martel, a registered dietitian at University Health Network (UHN).
Non-heme iron is already harder to absorb in our bodies compared to animal-source iron, said Jennifer Lee, registered dietitian and assistant professor in the school of nutrition at Toronto Metropolitan University, adding that this could be troubling for vegetarians and vegans whose main source of iron is from plant-based foods.
When having iron supplements or a meal containing iron, having excessive matcha could potentially block the iron-rich benefits of that meal from being absorbed by the body.
Do other foods have tannins?
A wide variety of plant-based foods contain tannins, including green and black teas, coffee, wine, some berries, chocolate and nuts.
But what makes the link between matcha and iron deficiency more prominent? It’s the higher concentration of tannins in matcha that could be inhibiting iron absorption more than other foods, Lee said.
Matcha generally has a higher a percentage tannins than other green teas because of how it’s grinded into a fine powder. Green tea is steeped in hot water, allowing for the tannin to dissolve, while matcha is much more potent because it’s being ingested.
Can excessive matcha consumption lead to iron deficiency?
If someone is habitually consuming matcha once or multiple times a day with iron-rich meals, iron absorption could be affected more regularly, Martel said, but she says this doesn’t always lead to iron deficiency in all people.
“A reduction in iron absorption at one meal or around one drink doesn’t necessarily mean an iron deficiency will be developed, as we have many other opportunities to get iron in throughout the day with our other meals and snacks,” she said.
Matcha beverages can also vary in the amount of tannins because some are diluted with milk and water, Lee said. She added that the source of the matcha is another factor in how much tannin there would be — with ceremonial matcha typically having fewer tannins than culinary grade, which is typically used for cooking and baking.
Although matcha generally doesn’t cause iron deficiency, it may lead to low iron levels in those already susceptible to anemia or who are iron deficient. This includes those who menstruate, pregnant women, perimenopausal women, vegetarians and young adolescents.
Common symptoms of iron deficiency include low energy levels, regularly feeling fatigue, hair shedding and increased heart rate.
Martel stresses that this side effect of matcha is not as prominent “as long as we’re consuming in moderation.”
What are some health benefits of matcha?
Matcha is rich in antioxidants that help relieve oxidative stress and inflammation in the body.
“Matcha contains an amino acid called l-theanine, which is known for its calming effects. And this, in combination with matcha’s natural caffeine content, provides a nice boost of energy, all without all the anxiety and jitters that come with coffee,” Martel said.
Kasjak still drinks a matcha beverage once a day, but she does so in what she believes is the healthiest way. She takes her matcha in an “Americano” style, using ceremonial matcha powder, whisking it in hot water and adding hot water to even out the bitterness.
She likes to drink it without a meal to avoid hindering iron absorption and has since seen improvement in her iron levels and symptoms.
What are some tips to balance your iron levels while drinking matcha?
Experts recommend matcha-lovers to drink the tea at least one hour before or after meals and/or taking iron supplements.
Keeping your minimum matcha intake to one cup per day can be a good tip for those more likely to be low in iron, said Martel.
Those who want to enjoy matcha everyday should aim to eat enough iron from a mix of plant and animal sources, including leafy greens, seeds, and tofu, she said, adding that pairing vitamin C rich foods with iron-rich meals can boost iron absorption.
