Is Green Tea Good for You? 3 Benefits Backed by Science

Of the three main types of soul-soothing tea—black, oolong, and green tea—green is most commonly linked to health benefits. So is green tea good for you? In short, yes, but many studies on green tea have been inconclusive. Let’s dive a little deeper….

Green tea originated in ancient China and has been consumed over the centuries in tea ceremonies and in medicinal treatments. As it contains an abundance of antioxidants, green tea has been linked to cancer prevention, oral health, and heart health. “A large portion of green tea’s connection to health is tied to bioactive components called polyphenols,” says Megan Meyer, Ph.D., director of science communications at the International Food Information Council. “Epidemiological data has shown that a diet rich in polyphenols is protective against health conditions such as heart disease and type 2 diabetes.” 

But much of this research has been observational, meaning the findings might not be entirely accurate. “A recent Cochrane Systematic Review of 142 studies looked at the role of green tea in the prevention of cancer and found there was limited evidence to suggest that green tea protects against cancer,” says Meyer.

So…wait. Is green tea good for you after all? There are still a ton of science-backed green tea benefits. Pour yourself a cup and read on.

Green Tea Benefits

It might be the most consumed tea in the world, but black tea has nothing on green tea’s nutritional properties. While both come from the same plant, Camellia sinensis, many benefits of drinking green tea are thanks to its lack of processing. Green tea is rich in protective polyphenols including catechins and epigallocatechin gallate (EGCG). These serve as potent antioxidants, which help to strengthen the body against disease.

1. Green tea may help treat acne.

You’ve seen it listed as an ingredient in your beloved undereye serums and Korean sheet masks, but does green tea actually benefit skin? Some studies suggest that consuming green tea and applying it to the skin may help to reduce sebum production—an oily material produced by your body’s sebaceous glands that can cause clogged pores—and treat common types of acne. However, further research is needed to properly assess the power of green tea in the field of skin health.

2. It may lower blood pressure.

Some studies have found that green tea consumption significantly lowers blood pressure, while other studies have drawn inconsistent conclusions. “In the context of cardiovascular disease, according to the National Institutes of Health (NIH), a small number of studies suggest that green tea may exert some beneficial effects on blood pressure and cholesterol,” says Meyer. “There are many limitations to these findings, such as differences in study populations and data analysis, so the NIH has stated that no definitive conclusions have been reached regarding the cardiovascular health benefits of green tea.” 

3. Green tea can fuel workouts.

You might have heard green tea being linked to weight loss, and in a way, this holds up. Green tea contains less caffeine than coffee and even black tea, but it still has enough to make an impact. Research has shown that caffeine reduces ratings of perceived exertion—how much it feels like your body is working—during exercise, meaning that consuming caffeine aids endurance and allows you to really commit to your workouts.

Green tea side effects

While there are benefits to drinking a steaming cup of green tea, excessive consumption can pose a risk to people with certain conditions and sensitivities. Here are the green tea side effects to watch out for:

1. Dehydration

According to the National Academies of Sciences, Engineering, and Medicine report, 80% of people’s total water intake comes from drinking water and beverages (including caffeinated beverages). However, green tea is a natural diuretic—a substance that stimulates the increased production of urine—which means drinking too much green tea can lead to dehydration, causing headaches, fatigue, and further health issues.

2. Reduces iron absorption

The polyphenols in tea are considered to be significant inhibitors of iron absorption, and one study found that consuming excessive amounts of green tea may lead to iron deficiency.

How much caffeine is in green tea?

One cup (eight ounces) of green tea contains approximately 28 milligrams of caffeine, although different green tea varieties and brands may contain more or less caffeine. “There’s a body of evidence that shows that mental performance and alertness are improved after caffeine consumption,” says Meyer.

How much green tea should you drink?

According to the National Center for Complementary and Integrative Health, it’s safe to drink eight cups of green tea each day. However, since green tea does contain caffeine, you might need to bear this in mind if you know the stimulant disrupts your sleep or causes other issues for you. “For most people, it’s safe to consume up to 400 milligrams of caffeine per day,” says Meyer. “According to the U.S. National Library of Medicine, if you exceed that amount, it can cause health problems such as insomnia, anxiety, nausea, headache, dizziness, restlessness, shakiness, and abnormal heart rhythm.”