Every Monday morning I receive a Google Alert for any big stories about tea that came out the previous week. As a tea nerd who occasionally consults for the beverage industry, I like to stay informed. I also like to torture myself by reading all the scientifically inaccurate headlines trotted out week after week without fail. “Which is the best tea for your health?” “The #1 best tea for nausea, according to a random dietitian.” “The best detox teas for losing weight.”
For better and mostly for worse, this is how we tend to talk about tea in the United States: as a vaguely medicinal concoction good for everything from shedding belly fat to reducing cancer risk. Forget all that other nonsense, like tea’s incredible diversity of flavors, or its culturally significant role in societies across the planet—if it won’t make you live forever, why bother drinking it at all?
This isn’t a tea problem. This is a scientific literacy problem, magnified by publishers’ hunger for clicks and marketers’ assurance that no one’s going to fact-check their often extravagantly outsize claims. I prefer to spend my time as a certified Tea Person showing people how beautiful tea can taste, but since the record needs setting straight, let’s talk about those stubborn tea myths to sort truth from fiction.
What kind of health benefits are in tea?
The short answer: All sorts, maybe, but it really depends.
Tea—specifically tea made from the Camellia sinensis plant—has been a subject of scientific study for decades, and tea consumption has been linked to everything from weight loss to promoting “gut health” to, no really, preventing cancer. This halo of healthiness has given marketers free rein to slap whatever benefits they want to on their tea packaging, with little enforcement. Even Covid remedy profiteering.
The problem is that many of these studies don’t show a causal relationship between drinking tea and a given health goal; there are all kinds of factors mitigating that relationship, or that offer alternative explanations. It just may happen that in the small sample of people studied, those who drink tea regularly and have lower blood sugar might also have diets with fewer carbs.
Of course, some studies have shown direct benefits as the result of drinking tea. Because of funding limitations, these studies usually run with small numbers of participants, or nonhuman species like mice, and are not always replicated to show consistent results. Plus, just because an effect shows up in a lab, that doesn’t mean it’ll make a significant contribution to your health goals—at least compared to more evidence-supported health practices like drinking water, exercise, and eating whole fruits and vegetables.
All of which is to say: There’s a lot of exciting data that tea may be able to enrich your diet and health—under certain circumstances, within limited parameters. But we just don’t have the scientific consensus and replicated studies necessary to make any bold claims about what a given type of tea can do for your body. Tea research is still budding (sorry). There’s a lot more study required before we can say anything definitive.
I drink tea because it tastes good and makes me feel good. Anything more specific is, at best, a reach.
How much caffeine is in tea compared to coffee?
After the health benefits talk, the next biggest topic in American tea talk is all about caffeine. People love caffeine! But they also love cutting back on it, and many coffee drinkers looking to do so opt for tea as their morning brew instead. (As for why these drinks are presented as binary options, where you can only be a Coffee Person or Tea Person…that’s above my pay grade.)
According to the Mayo Clinic, the average adult can safely consume up to 400 milligrams of caffeine per day before vibrating to a plane of non-corporeal existence. Your typical 8 ounce cup of coffee contains about 96 mg, and a shot of espresso has about 64 mg. Those numbers can vary depending on the brewing method, water temperature, and even the duration of that brew; the roast level doesn’t matter, as light and dark roast coffees contain similar amounts of caffeine.
A cup of tea made from the Camellia sinensis plant contains anywhere between 28 and 48 mg of caffeine—a half to a third of a cup of coffee—so if you’re sensitive to caffeine or just looking to cut back, tea is a nifty alternative. The exact amount of caffeine in a given cup is influenced by all sorts of factors, including the processing methods, size of the leaves, and climate conditions where the tea was grown.
Do some types of tea contain more caffeine than others?
I’m not sure where this myth first originated, but to this day, reputable news sources parrot unsubstantiated claims about different types of tea containing more or less caffeine than others. Usually the line is that green tea is less caffeinated than black tea, because it’s “less processed” or contains a greater concentration of antioxidants.
While processing style can play a role in caffeine content, all types of tea—black, green, white, oolong, and post-fermented—have been shown, on average, to contain similar amounts of caffeine in lab tests. Sometimes, tea sellers will label a particular tea as containing high, moderate, or low amounts of caffeine. But unless they’ve sent that specific batch off to a lab to test it, they’re likely making it up.
Can I flush out the caffeine by tossing my first steep?
There is another stubborn caffeine myth in the tea world: that most caffeine in a tea gets released in the first minute of brewing, so if you steep for 60 seconds, dump your brew, and steep again, you can “decaffeinate” a tea yourself. In recent years, online publications have started debunking this claim, but it manages to persist in some tea shops and communities as wish fulfillment among drinkers and a sneaky marketing tactic among sellers.
Lab analysis has shown that, just like with coffee, the longer you steep your tea, the more caffeine will be released into your cup. Higher temperature water will draw out more caffeine as well.
Green teas like sencha and jasmine are often brewed in cooler water for a shorter time, to draw out their vegetal sweetness without turning bitter. If you’re sensitive to caffeine, give these teas a try—not because they contain any less, but because they can be brewed in a way to limit the amount of caffeine that shows up in your cup.
What about herbal tea?
I’m so glad you asked. All the types of tea we’ve talked about so far come from a single plant, the Camellia sinensis shrub. Herbal teas like chamomile and mint come from other plants, and pretty much all of them are free of caffeine. That’s also true for roasted grain teas like buckwheat or barley, and if you’re trying to kick a coffee habit, these toasty, nutty teas may be right for you.
There are a few herbal teas that do contain caffeine: yerba mate, guayusa, and yaupon. All three are members of the holly family and native to North and South America, where indigenous people have long dried the leaves and brewed them into caffeinated drinks.
Ultimately, the only way to really know how the caffeine in tea will affect you is to see for yourself. Everyone’s body is different, and while we can quantify the amount of caffeine in a cup of tea or coffee, we can’t predict how your body will respond to it. A snack helps, and also heads off the feeling of gut-rot that comes from drinking tea or coffee on an empty stomach.
You know what else helps with caffeine? Sleep. Which caffeine is not a replacement for. Just saying.
