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Matcha and Pregnancy: Potential risk for the baby?

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by Siadra

Updated January 17, 2021

Safe levels

Safe levels of matcha for pregnancy: 1-3 cups per day (8oz cup size)

Safe levels of caffeine for pregnancy: 100 to 200 mg per day

Matcha and pregnancy have a high level of association with each other. From one point of view, it seems matcha could be the healthiest drink you can drink during pregnancy. We chose to investigate this on a deeper level- analyzing credible research findings and shaping it in a form that would make sense to you. And it seems what is popular is not always good.

The big question: Can you drink Matcha during pregnancy?

Yes, you can drink matcha during pregnancy in moderate amount only. But it’s best to avoid altogether, and you will know why by the end of this article.

To make it a ‘yes,’ you must take these things into consideration:

  • Keep the daily total caffeine intake below 200 mg as recommended by the American College of Obstetricians and Gynecologists. So, that translates into approximately 3 teaspoons of matcha per day.
  • We recommend keeping the total caffeine of about 100 mg per day, which means you can consume 1 and a half teaspoon of matcha per day.
  • For heavy tea drinkers, decaf green tea or decaf matcha is the best way to go.
  • You also need to take into consideration other caffeinated beverages that you might drink throughout the day.
  • Always drink matcha 1 hr or more before any meal.

What’s matcha and why do pregnant women drink it?

Matcha is simply powdered green tea leaves. So, we used green tea as a representative of matcha to conduct our analysis. Traditionally, we consume only the extracts of green tea leaves by infusing with hot water. But in the case of matcha, you are consuming all of the leaves.

So, it’s more concentrated and has more flavors and nutrients than traditional green tea. Pregnant ladies who have a craving for stronger caffeinated beverages like coffee or cola, choose matcha or green tea as it has less caffeine and more polyphenols. Don’t fool yourself and drink as much as you want. If you go down further, you might get shocked knowing the side effects of drinking high or even moderate levels of green tea.

We listed some of the benefits of drinking green tea during pregnancy here:

  • Great for controlling gestational diabetes: The polyphenols in green tea lowers blood sugar levels in pregnant women. So, if you have gestational diabetes, drinking green tea will keep it under control.
  • Tackle mood swings: The antioxidant effect of green tea increases metabolism rate, and so it gets easier for you to counter mood swings.
  • Improve immune system: Green tea promotes the increment of certain cells in the body that plays a crucial role in immune function. So, mild illnesses will have less effect on you.

Now that you know the benefits let’s investigate the adverse effect of consuming green tea during pregnancy.

What makes matcha and pregnancy relationship negative?

There are two primary components of green tea: Polyphenols and caffeine. While caffeine level requires a certain level of moderation even without pregnancy, polyphenols are considered healthy. But during pregnancy, both these components can become the primary reason to avoid or restrict green tea consumption.

Effects of Polyphenols in green tea on pregnancy:

If you believe the antioxidant characteristic of green tea can help you remain healthy during pregnancy, then you are seriously going in the wrong way.

1. Polyphenols in green tea can cause neural tube defects

Matcha or green tea has more polyphenols or catechins than black tea. If you are a green tea lover, that’s wonderful!

But are polyphenols safe during pregnancy?

To understand this, you need to know about two things:

  • The function of folates in pregnant women
  • The effect of polyphenols on folates

Folate is a nutrient that is stored in the small intestines of pregnant ladies. This is a life-saving nutrient that can prevent your baby from developing Neural Tube Defects (NTDs).
NTDs are birth defects related to the spine, brain, and spinal cord. The most common is Spina Bifida, which leads to paralysis of your baby’s legs long before his birth. EGCG is a polyphenol found in green tea that lowers the level of folate in the intestine of mothers. This starts from the beginning of the first trimester and through the end of pregnancy. As a result, your child can have a serious risk of NTDs like Spina Bifida.

The following 4 research studies provide evidence to our finding:

  • In a survey of 321 pregnant Japanese women, who regularly consumed green tea and oolong tea, it was found that consumption of just 100-130 ml of green tea significantly lowered folate levels.
  • Researchers in an experimental study found that subjects who ingested 0.4 mg of folic acid supplements with green tea had a 39.2% reduction of folate levels.
  • A study on birth defects in Atlanta also reveals that pregnant ladies who drank 1-2 cups of green tea per day also had a high risk of NTDs compared to women who drank 3 or more cups per day.
  • A Chinese study found more alarming issues. It was found that the risk of having an NTD-affected baby was 3 times more when women drank green tea during the periconceptional period. Along with Spina Bifida, researchers also found a link to Anencephaly and Encephalocele.

2. Green tea during pregnancy third trimester can decrease fetal growth

If you managed to avoid drinking green tea during your first trimester, the risk is not over yet. Many women believe that green tea during pregnancy third trimester is safer than the first trimester.

It’s all wrong! First, you need to know about Fetal Ductal Constriction, which is also known as Intrauterine Growth Restriction. This is a condition when your baby still inside womb remains smaller than he should be. This delayed growth also includes low birth weight, low resistance to infection, decreased oxygen levels, and many more. When you drink green tea, the polyphenols present in it causes an anti-inflammatory effect by inhibiting prostaglandin.

This is great before pregnancy.

But during pregnancy, inhibition of prostaglandin can lead to Fetal Ductal Constriction and delay your baby’s growth. In a study of fetal lambs, green tea was administered in different doses to the mother lambs. The findings show that within just 1 week of regular green tea consumption, certain symptoms of Fetal Ductal constriction appeared. And the signs also diminished when the effects of green tea were withdrawn. It can be more dangerous when you consume matcha as the amount of polyphenols, and their concentration will be higher than regular green tea bags. Green tea is not the only culprit. If you consume any sort of dietary foods that contain polyphenols with anti-inflammatory and antioxidant effects, there is still a risk of this type of birth defect.

3. More polyphenols mean less absorption of iron

Why do pregnant women need iron?

Iron is a transporter of oxygen without which you and your baby will suffer from anemia. Deficiency of iron can lead to fatigue, shortness of breath, heartbeat increment, and pale skin. In fact, irons are most important during the second trimester of pregnancy. During this phase, your blood volume might increase by 40-50%. So, you will need more irons to make your blood healthy. For more irons, you will need to eat iron-rich foods like red meat, poultry, and green leafy vegetables.

Here comes matcha green tea.
If you drink it on a regular basis during this pregnancy phase, it will restrict the absorption of iron considerably from non-meat sources. Research reveals that drinking tea during meals and after 1 hour of meals can reduce iron absorption by 64%.

The reason: Green tea or any tea, it has polyphenols and tannins that hinders the process of iron absorption.

In a study, polyphenols served along with a bread meal, reduced the ability to absorb iron by 50-70%.

And another study found evidence that only a 5mg dose of tannin can increase iron inhibition by 20%.

The Solution: Drink green tea at least 1 hour before the meal not after or during the meal. More gap is better.

Effects of Caffeine in green tea on pregnancy

1. Association of green tea with miscarriage

Can green tea cause miscarriage?

Yes, it can! It’s all about caffeine. In fact, any caffeinated beverage can increase the chances of miscarriage in pregnant women. The risk is higher during the first trimester.

Here are the reasons:

  • Caffeine, when consumed during pregnancy, gets quickly through to the fetus. But as the fetus has a very low metabolism rate, caffeine is released very slowly.
  • The fetus cell development might also be hindered by caffeine because it can increase the concentration of cellular cyclic adenosine monophosphate.
  • Caffeine can also restrict placental blood flow, which means your baby will get less oxygen.

In a study of 1063 pregnant women based in San Francisco, the results show that the risk of miscarriage increased by 15% when caffeine consumption was below 200 mg. The risk became 25% among women who consumed more than 200 mg caffeine. What’s more alarming is that if you never had any miscarriage before, drinking green tea or other caffeinated causes a higher risk of miscarriage.

Further research also confirms the fact that there is a clear association of spontaneous abortion during the first trimester, whether you consume caffeine in moderate or high amount. Keep in mind that caffeine is not the only cause of miscarriage during pregnancy. Your age and smoking habit can also decide the final outcome.

2. Caffeine during pregnancy can damage the baby’s heart for a lifetime

The combination of matcha and pregnancy can be a cause of decreased cardiac function during the first trimester of pregnancy. Only one instance of drinking 5 cups of matcha or green tea is enough to reduce the cardiac function of your baby to as much as 38%. This reduction in cardiac function is likely to continue into adulthood. A study done on pregnant rats confirmed this. Caffeine consumption separated a few of the heart’s chamber by thin layered embryos. If we apply the results of this study to humans, there is also a chance that your future male child will have 20% more body fat.

3. Risk of preterm birth

Association of green tea with pregnancy can result in Preterm Birth. This is a condition when your gestation period ends in less than 37 weeks. Preterm birth can cause malnutrition in your baby, and you will want to avoid this at any cost. When you consume caffeine in the form of green tea or any beverage, it reaches the fetus quickly. But due to the lack of a caffeine metabolism enzyme known as cytochrome, caffeine exposure becomes high in the fetus.

The result is increased catecholamine levels, which leads to the preterm birth condition. We analyzed a Japanese study conducted on 858 Japanese mothers. The results show that drinking green tea during pregnancy third trimester is 3.7 times riskier than consuming at the beginning of pregnancy. The risk for preterm birth becomes higher if you exceed the recommended level of 200 mg of caffeine. But the risk is still prevalent if you consume less than 200 mg of caffeine.

Questions pregnant women often ask:

  • This is one question that pregnant mothers often ask doctors and intellectual friends. Let’s face it! Research confirmed that less than 1% of the caffeine from green tea filters into the breastmilk. This is totally okay for your baby, and no adverse risk is associated. But if you consume more than 3 cups of green tea or equivalent to 1 cup of matcha per day, these side effects can be observed in your baby: 1.Irritability and fussiness. 2.Sleep pattern change and wakefulness. 3.Intense crying for prolonged periods. In a study of 885 breastfeeding mothers, caffeine caused no side effects when the consumption was less than 300 mg. (18). So, yes. You can drink matcha during breastfeeding. But try to keep the caffeine level as low as possible.

  • Matcha is a rich source of polyphenols. This polyphenol helps to prevent chromosomal abnormalities. Hypoxanthine found in green tea can help eggs get matured and promote fertilization. 210 women were studied in a research program and found that chances of becoming pregnant became twice compared to when no green tea was consumed. But as we discussed earlier matcha can cause miscarriage and neural tube defects during the first trimester. So, when to consume matcha? It’s best to start drinking no more than one cup of matcha from day 1 of your period until the day of ovulation.

  • Decaffeinated green tea is the safest form of green tea you can drink during pregnancy. This is almost an ideal green tea for pregnant ladies. Though it still contains caffeine and polyphenols. But the amount of caffeine is just 12 mg per cup. If you choose to stick with decaf matcha or green tea, you can drink more cups throughout the day. The only issue is in the taste. Many hard tea drinkers don’t really like the taste of decaf tea versions. So, it’s totally up to you!

Final thoughts

Matcha and pregnancy can make a dangerous combination if you exceed the recommended daily intake of 200 mg caffeine. Even just 100 mg of caffeine per day is enough to trigger the risk of neural tube defects. So, drink matcha in moderation- just a cup or two a day is safe enough.