The Healthiest Types Of Tea, According To A Functional Medicine Expert

If I had to drink one thing for the rest of my life, it would be tea. When I am consulting with patients I almost always sip on a variety of different tea elixirs.

The world of tea offers something for everyone, depending on your taste, mood, and health goals. All true tea comes from the tea plant Camellia sinensis. That's right, black tea, green tea, white tea, and oolong tea all come from the same plant—everything else is technically a tisane (herbal tea). What makes them so unique in look and taste is the way they are grown, harvested, and prepared.

All teas contain bioactive ingredients with antibacterial1, antioxidant2, anti-inflammatory, and antiviral properties that can translate into health benefits. But, each type of tea contains its own individual characteristics that can help you better decide which will be your go-to choice.

When ranking these teas, I took into consideration levels of key antioxidants, caffeine amount, and propensity to contain heavy metals.

Even though tea tends to have less caffeine than most coffee, all of these teas have some caffeine. Whether caffeine is a positive or negative for you may be a personal preference, but can also involve your DNA—specifically, a gene called CYP1A2.

This gene codes for an important enzyme, specifically cytochrome P450 family 1 subfamily A member 2 (CYP1A2 is the abbreviation). It's part of the cytochrome P450 superfamily of enzymes, which are critical for important functions like metabolism of drugs and chemicals in the liver. As it turns out, CYP1A2 is responsible for most (about 95%) of caffeine metabolism3.

One variant of this “caffeine gene” causes the liver to break down caffeine very quickly. Those of us who have the AA genotype handle coffee and tea like a boss. These fast metabolizers break down caffeine4 significantly more quickly than those people who inherited the slower variant of CYP1A2, the AC/CC genotype.

Does that mean that if you are a slower caffeine metabolizer you shouldn't have any tea? For most people, the benefits of tea outweigh the caffeine amount. Just limit your intake, and if it makes you feel jittery, just cut back or go decaf (which still has some antioxidants).

White tea tends to have the least caffeine, but for all varieties, it really depends on the source, the amount you are using, the brewing temperature, and how long you steep your tea.

Heavy metals can be found in plant products because these metals are absorbed from the soil. Tea can absorb lead, mercury, arsenic, cadmium and other toxins5. White tea, because it is picked sooner, is known to have lower amounts5 of these toxicants on average.

Tea leaves can also be exposed to pesticides6. To limit pesticide residues, opt for organic options whenever you can to further minimize any unnecessary chemical exposure. In addition, buying higher quality teas and not over-steeping are practical ways to limit toxins in tea.

This tea is made from brand-new growth buds and young leaves of the tea plant. In order to inactivate oxidation, the leaves and buds are steamed and then dried. Since it is minimally processed, its antioxidants, especially catechins7 (a type of polyphenol), are well preserved and can be higher than that of other varieties of tea. Depending on the tea samples studied, other studies report polyphenolic content8 to be similar between white and green teas.

White tea is characterized by its light color and mild flavor. It is an extremely easy tea to drink and has the lowest caffeine content on average of all tea types, making it a great choice if caffeine isn't your thing but you still want a little pick-me-up.

Green tea is definitely popular right now. While harvested later than white tea, green tea does not go through the same oxidation process that oolong and black tea go through. Like white tea, this allows for some of the highest levels of catechins, specifically the uber-beneficial compound epigallocatechin gallate (EGCG)9.

Green tea and EGCG have been shown through research to benefit important health processes underlying cardiovascular and metabolic health10, as well as cancer9. Additionally, green tea has a famous amino acid, L-theanine, known for its relaxant and anti-anxiety11 properties.

Green tea comes in different forms. Each has their own individual taste and array of bioactives. Here's how the different green teas rank:

Matcha is a green powder made from grinding up a specific kind of green tea leaf. Unlike many other green teas, plants used for matcha are first covered and grown in the shade for many weeks before they are harvested, resulting in boosted chlorophyll levels12, which gives matcha the bright green color it’s known for. Then the leaves are dried and ground into powder. Matcha has one of the highest concentrations of EGCG of all green teas, up to three times more13 than a typical sencha!

Sencha is brewed by infusing the whole tea leaves in hot water to produce a very mild and pleasant taste. Harvested early on in the season, sencha is made from some of the most flavorful top leaves. It's no wonder that this is the most popular tea in Japan.

Similar to sencha, the biggest difference is that the leaves are also shade grown just like matcha versus in the sun, which results in a stronger, more intense flavor.

More bitter in taste, bancha has the lowest caffeine content of all green tea varieties. It is harvested from the same tree as sencha but later in the season, making it one of the cheapest, most commonly found green teas out there.

When the tea leaf is harvested to make black tea, enzymes are activated, resulting in oxidation, leading to a withering of the leaves. Depending on the specific temperature and humidity controls, the leaves brown, and the desired taste and aroma is achieved.

Many types of black teas are blends of different varieties of black teas from different regions. It also has the highest caffeine content of all tea types on average.

Since black teas are oxidized, the catechins originally present are converted to theaflavins. While the high catechin content in green tea is a major health benefit, studies have shown14 that theaflavins are just as powerful antioxidants, making black tea a perfect choice if you are needing a boost of caffeine and want the antioxidant benefit.

Black teas don't tend to differ too much in health benefits; choosing the right one for you is really a matter of taste. Some of the most common black teas include:

Often blends of Assam, Kenyan, and Ceylon varieties of black tea, the most common breakfast tea is English breakfast. To everyone in the United Kingdom, this is the only tea that exists—all else is sacrilegious.

Also quintessentially British, Earl Grey tea is black tea blended with bergamot oil (from the rind of the bergamot orange fruit).

If black, green, and white tea are Destiny's Child, oolong is the overlooked member of the group who got kicked out sometime in the late '90s. But oolong is awesome!

Oolong tea is produced similarly to black tea, except oolong is oxidized for half the time. Although the mechanisms are still shaking out, research demonstrates that dark teas like oolong help favorably modulate our gut microbiome15.Oolong tea is also thought to increase metabolism16 and fat oxidation, thereby impacting body weight. More studies are needed in this area.

The bottom line? All teas are healthy beverage options, so choose based on your personal goals, genetic makeup, and flavor preferences.