Green Tea vs Black Tea: Caffeine, Health Benefits & When To Sip Each

While both green tea and black tea are considered healthy drinks, you may wonder if one is better for you than the other. Though green tea is often thought of as the "healthiest" tea due to its high antioxidant content, black tea has some surprising perks to offer too. 

This article breaks down the differences between green and black tea, including their caffeine content and potential benefits, to see which one's the best for health.

What is black tea?

All true tea, including black tea and green tea, is made from the leaves of the Camellia sinensis1 plant.

Black tea has a much stronger flavor and darker color than other types of tea, like green tea and white tea, because it undergoes more oxidation (exposure to air), resulting in its characteristic color and rich taste. 

Black tea has a rich, malty flavor and is often enjoyed with a splash of milk or cream. Black tea can be purchased in tea bags or in loose leaf form, and is also found in tea blends, like chai tea.

Caffeine content

The caffeine content of black tea varies, but research suggests it contains around 47 mg per cup2. For comparison, a cup of brewed coffee3 contains 91.8 mg of caffeine.

Types

There are a variety of black teas to choose from, including:

Generally, black teas are named after the region in which they were produced. For example, Assam black tea hails from Assam, a state in northeastern India. 

Black tea can also be combined with ingredients like essential oils to create tea blends with different flavors. The popular Earl Grey tea is made by blending black tea with bergamot oil, for example.

Health benefits

Black tea is rich in health-promoting compounds1, like the polyphenol antioxidants theaflavins and thearubigins, which are responsible for its bitter taste and dark color. These substances provide major benefits for your body, such as protecting against cellular damage4 and reducing inflammation.

Study findings suggest that regularly drinking antioxidant-rich black tea may help reduce the risk of several health conditions, including depression5, breast cancer6, and type 2 diabetes7. 

A study found that people who consumed more than one cup of black tea per day had a lower risk of depression5 compared to people who drank less than one cup. 

Black tea contains multiple compounds, including polyphenols and the amino acid L-theanine, that may reduce depression risk by modulating the activity of the neurotransmitter dopamine8 and the gut-brain axis—a signaling pathway between the digestive tract and the central nervous system. 

What is green tea?

Green tea comes from the same plant but looks and tastes different from black tea.

Green tea undergoes less oxidation, allowing the tea leaves to retain their green color. It has a less intense taste than black tea, often described as grassy and slightly sweet. 

"Green tea does not go through the same oxidation process that black tea goes through," functional medicine practitioner Will Cole, IFMCP, DNM, D.C. previously told mindbodygreen. "This allows for some of the highest levels of catechins11, specifically the ultra-beneficial compound epigallocatechin-3- gallate (EGCG)," says Cole.

Like black tea, green tea can be purchased in tea bags and as loose-leaf tea. You can also find it in powdered form as matcha tea. Green tea is usually enjoyed plain, but some people use lemon juice or sweeteners, like honey, to enhance the tea's flavor. 

Caffeine content

A cup of brewed green tea12 contains only 29.4 mg of caffeine, which is significantly less than black tea. Since it's low in caffeine, people who are sensitive to caffeine's stimulatory effects can enjoy green tea without experiencing side effects like jitteriness and trouble falling asleep. 

Types

There are several types of green tea, each grown in different ways and harvested during different seasons. They include:

Sencha green tea13, the most common type of green tea consumed in Japan, comes from the first flush of green tea leaves, while bancha green tea is harvested later in the season, during the last flushes of the tea plant. 

Matcha is a type of concentrated green tea powder that's a rich source of antioxidants like flavonoids, flavonols, and phenolic acids, which compose up to 30% of its dry mass14. Matcha has become quite popular in the U.S. over the last decade and is commonly enjoyed in hot beverages like matcha lattes and in iced drinks.

Health benefits

Experts attribute the health benefits of drinking green tea to its high concentration of polyphenol antioxidants, including catechins like EGCG and the flavanols15 kaempferol, myricetin, chlorogenic acid, quercetin, and theogallin.

EGCG is one of the most well-known and studied compounds found in green tea and it has been shown to have powerful anti-inflammatory16, antioxidant, neuroprotective, and antidiabetic effects in the body. 

Like black tea, green tea is also high in L-theanine, which has anti-stress properties20. Studies suggest that drinking green tea may help boost mood and protect against depressive symptoms, which is partly due to its high L-theanine content.

A small study found that drinking six cups of decaffeinated green tea per day for six weeks helped reduce the depression, anxiety, and stress associated 22with stuttering and significantly reduced elevated levels of the adrenal stress hormones cortisol, DHEA, ACTH, and corticosterone in teens with moderate stuttering.

Which one's healthier?

While both green and black tea have been associated with several impressive benefits, green tea may slightly outshine black tea when it comes to its effects on health.

That's because green tea contains higher levels of certain protective plant compounds than black tea, including EGCG and L-theanine, and may have more powerful disease-fighting properties. (Hence why it was named the best tea for overall health in mindbodygreen's power ranking.)

A study found that green tea intake was linked to a higher likelihood of healthy aging23 in Greek adults aged 50 years and older, while black tea consumption was negatively associated with healthy aging.

The study also found that green tea drinkers were more likely to be physically active and had a reduced risk of high blood pressure compared to black tea drinkers. These findings were attributed to green tea's high levels of L-theanine and catechin compounds. 

Studies also show that drinking green tea, but not black tea, significantly reduces the risk of cognitive disorders24 in some populations. Researchers suspect that its high level of catechins gives green tea an edge when it comes to its brain-protective effects. Green tea also contains a small amount of vitamin C, which has cognitive health-enhancing and neuroprotective properties25.

Even though green tea might have a slight edge over black tea, it doesn't mean you have to choose one over the other. In general, drinking tea has been shown to benefit health, so whether you choose to drink green tea, black tea, or both, should be based on your taste preferences and caffeine tolerance and not on health concerns. 

"All true teas offer a slew of health benefits, including effects that support brain and heart health. While it seems that more data is available highlighting the benefits of consuming green tea, that is not to say that black tea is less beneficial to consume," registered dietitian Lauren Manaker M.S., RDN, L.D., tells mindbodygreen.

Also, remember that no one food or beverage will significantly impact your health alone. Your diet as a whole is what matters most when it comes to promoting optimal physical and mental health and reducing disease risk. Green and black tea can offer benefits, but they can't make up for an unhealthy diet.

Which one should you choose?

If you're wondering which tea you should choose, it really comes down to your flavor preferences and caffeine tolerance. Here's a bit more info to help you decide on a tea that best suits your needs.

Best tea for energy boost in the morning: Black tea

If you're looking for a tea to give you an energy boost in the morning, consider black tea. Black tea contains more caffeine than green tea, so it may help you feel more alert.

However, people looking for a more mellow way to start their day, or those sensitive to caffeine, may want to opt for green tea. Green tea is higher in L-theanine26, an amino acid that has calming and mood-boosting effects on the body, than black tea.

Best tea to sip before bed: Choose decaf

Green tea and black tea are caffeinated, so they're not the best choice to drink in the evening, especially if you're sensitive to caffeine. Instead of sipping on caffeinated tea before bed, you can enjoy a cup of decaf green or black tea or a naturally caffeine-free herbal tea like chamomile, which has sleep-promoting properties27.

Best tea for weight loss: Both

Even though drinking tea won't affect your weight unless you change your diet and lifestyle as well, some evidence suggests that green and black tea may positively affect body weight and fat distribution. For example, high consumption of green tea may help protect against abdominal fat accumulation28 in women, while black tea intake may inhibit weight gain29.

Just make sure to wait a few minutes after brewing to enjoy your tea, as studies have linked regular intake of drinks above 140℉ with an increased risk of esophageal cancer30.

Best tea if you're sensitive to caffeine: Green tea

If caffeinated bevs make you feel anxious and jittery, chances are you're sensitive to caffeine. Green tea is an excellent choice if you're looking for a tea with low caffeine content. One cup of brewed green tea only contains 29.4 mg of caffeine, which is much less than what's found in coffee and black tea.

"Green tea contains less caffeine than black tea, and it may have more antioxidant effects as well," says Manaker.

Best tea for stress relief: Matcha

Buying tips

When shopping for green or black tea, you should keep a few things in mind:

First, consider your taste preferences. Remember, there are different types of green and black tea, each with a different flavor. For example, you might prefer matcha or bancha green tea if you like stronger-flavored green tea.

Black tea drinkers looking for a lighter, less malty-flavored black tea may want to try Darjeeling tea, which is thin-bodied with fruity and floral flavor notes.

Another factor to consider is cost. Some teas, like high-quality matcha and certain types of black tea, can be very pricey, so it's essential to shop around until you find a tea that fits your budget.

To save money, you can purchase tea in larger quantities as bulk items are usually sold at a discount. When stored properly, loose-leaf tea can last in your pantry for up to two years, and tea bags can last up to three years. 

Also, whether you're buying green or black tea, it's important to purchase products from reputable companies and opt for organically grown tea whenever possible.

Lastly, when purchasing tea in bags, steer clear of tea bags made with nylon, such as "silken" tea bags. These bags can leave behind microplastics33 in your tea, which can build up in your system over time and potentially harm your health.

For a safer way to brew tea, consider investing in a steeper made of nontoxic material, like stainless steel.

The takeaway

Green and black tea both offer several benefits, from providing health-promoting antioxidants to protecting against common health conditions.

Although green and black tea can both be enjoyed as part of a healthy diet, green tea offers more benefits when it comes to antioxidant content and its positive effects on metabolic health and cognition.