Everyday Tea Myths: Caffeine, Detox, Organic Tea, Pesticides, Tea Bags and More

The sections below take each row in turn, with the details behind the verdict.

Tea 101 puts black tea at about 50 mg of caffeine a cup and green tea at about 20 to 45 mg, against about 90 to 95 mg for coffee. Oolong usually falls between green and black, and white tea varies. The amount in your cup depends on the leaf, how much of it you use, the water temperature and the steeping time. To help, our product data now gives each tea a caffeine rating of High, Medium, Low or Caffeine-free.

The caffeine is there for the plant, not for us. Our staff training deck explains that the tea plant makes caffeine, along with the related compounds theobromine and theophylline, “as a way to ward off insects and other animals.” Peter Keen called it one of the most effective natural pesticides, one that discourages many of the 300 or so main tiny pests that feed on the leaf. For the full picture, see Caffeine in tea.

Green versus black

Green tea’s healthy reputation owes a lot to marketing. A report on our blog from the 2015 Sydney Tea Festival noted that the Chinese and Japanese tea industries promoted green tea as a healthy drink, while the black tea boards did not promote black tea nearly as well.

Peter Keen found no evidence, scientific or experiential, that green tea is “better” from a health perspective than black or oolong. “It’s about as meaningful as distinguishing the medical benefits of green apples versus red ones. It’s the apple that matters.” His advice was to choose by quality, whatever the color: a really good green such as Jasmine Pearls, an estate black Darjeeling, a Wuyi oolong or a top white such as Silver Needle, all “so, so good to savor.” For a Darjeeling green and black side by side, try our Darjeeling Green Tea and Darjeeling Thurbo Spring Chinary.

Asked whether green tea makes you lose weight, one of our writers answered in 2014: “No. Just no.” The writer had spent hours looking for a definitive study that proves green tea helps you lose weight and could not find one. No tea melts fat; see Tea and weight loss for what has and has not been studied.

“Detox” describes a feeling a brand wants you to have, not a measured effect. No tea has been shown to remove toxins from the body. Peter Keen described a community that talks up tea’s “cleansing effects” and natural ingredients, and found its claims weak: it too often takes research that says “may” and “seems” and reports it as “proves.”

Slimming claims travel fast online. On Amazon, Keen found an oolong sold for “naturally melting away belly fat,” and asked readers to check whether the information behind such a promise is sound “and not just opinion presented as fact.” A simple rule follows: if a tea promises to cure, cleanse or melt anything, it is selling a promise, not a tea.

Tea has small amounts of some vitamins (B1, B2 and, in green tea, C), but Tea 101 calls them “small enough to be negligible,” and our old article added that there is “no vitamin C in black tea at all.” The reason is simple arithmetic. Our training deck puts a brewed cup at “on average 98% water and 2% compounds from within the tea leaves.”

Where tea did become food, it was because of what was added to it. In Tibet, meat and dairy country, tea turned into a kind of soup, butter tea. In most of the world, fresh fruit and vegetables are a far better source of vitamins than any cup.

Skin and teeth

Our 2015 article said “true” to both. It claimed that tea’s antioxidants prevent wrinkles, that a poultice of leaves could “detox the skin,” and that fluoride in tea benefits teeth. That went further than the evidence for drinking a cup of tea, so we no longer say so.

Fluoride claims get the plant backwards as often as not. Peter Keen came across an advertisement saying the “high fluoride content in white tea can neutralize plaque.” In fact, he explained, the tea bush takes fluoride up from the soil and older leaves hold more of it, so white tea, made from the youngest spring buds, has the least fluoride of all.

Organic certification allows chemicals approved by each country’s regulator. Rajiv Gupta, an agriculture graduate with 16 years in the field, explained it on our blog in 2014: the line between organic and conventional farming is drawn by government, so a farm can use many different approved pesticides and still be labeled organic. Peter Keen added that the organic label is “more an expensive certification than a pervasive solution,” and that it does not vouch for lead residues in the soil. See Tea certifications explained.

How worried should you be about pesticides?

Peter Keen, after looking at more than 200 published items, advised being wary of both scare stories and shrug-it-off ones. His overall reading was that “tea is safer than most agricultural products,” and that buyers can lower their own risk by choosing mountain-grown teas. He gave reasons rather than reassurance:

• Pest pressure: tea grows in humid climates full of insects, and uncontrolled crop losses can run anywhere from 10% to 55%, so most tea farming uses some form of pest control.
• Mountains help: high slopes have few roads, so less traffic pollution and fewer heavy loads of chemicals carried up, and a cooler climate with fewer pests.
• Two kinds of tea business: artisan whole-leaf teas made up only about 15% of the market, while the 85% agribusiness segment is driven by cost and volume.
• Detail beats headlines: the more detailed a scientific study of residues, the less scary its conclusions tend to be.

His practical advice was to buy single-estate teas with a clear origin, season and source, and to avoid generic blends and anonymous teas. He compared tea labels with sausage labels: “selected black tea” tells you as little as “processed meat.”

India also sets legal limits. The Indian Standard for green tea, IS 15344, sets maximum levels for pesticide residues and for lead in the finished tea. We buy from more than 250 Indian estates, and every tea we sell is tasted and selected by our team in Siliguri, at the foot of the Darjeeling hills.

Tea is an agricultural product and goes stale with time, light and air. Our 2014 blog put it bluntly, “the longer you keep it around, the staler it gets,” and advised drinking it within four months, at a time when it put tea’s shelf life at six months from the date of picking. Our storage guide now says that, kept airtight, dark, cool and dry, most tea is at its best within about a year of being made, and an earlier Teabox tin was printed “Best before 24 months from packaging.” See How to store tea.

Freshness starts long before your cupboard. Our team tastes each tea at the garden once it is made and brings the lots that pass into our facility within 24 to 48 hours of production, where they are vacuum packed, hand sorted and graded. Between packing and shipping, the tea is kept at -5°C.

Tea bags and loose leaf

The quality of tea depends on the type of leaf and the method of processing. The finest teas are usually orthodox, rolled whole leaf made from the tenderest shoots and unopened buds, while CTC (crush, tear, curl) tea is made from more mature leaf. Tea dust is the lowest grade of all, imparts a harsh flavor, and is what usually goes into tea bags.

That is a matter of taste, and you can test it yourself. In 2024 we asked customers to compare dust and whole leaf tea side by side, because there is “a whole lot of difference in taste” and experience. Peter Keen saw no reason to buy mediocre tea in bags: “There are so many whole leaf ones that cost the same and taste better.” More on grades in Tea grades explained.

True tea comes only from the Camellia sinensis plant. Infusions of other plants, such as chamomile, ginger, ginseng or hibiscus, are tisanes, usually caffeine-free, often sold as “herbal tea.” Some blends mix tea leaves with herbs and spices, and Indian masala chai is a delicious example. See Herbal tea, or try our caffeine-free Pure Chamomile, whole flowers from the foothills of Uttarakhand.

“Chai tea” means “tea tea”

“Chai” is Hindi for tea, so “chai tea” is a redundancy, as Peter Keen pointed out in 2017. We have been called out by fellow Indians for using “chai tea” in our own ads. We did it because that is how the name became popular around the world, but the correct way is just to say chai, which usually means black tea brewed with milk, sugar and spices. More in What is chai?

“Tea will stunt your growth”

Vinayak Varma, writing for our blog in 2016, grew up in a Malayalee household being told “that tea stunts mental and physical growth in children.” Tea was “too strong for children,” the aunties and uncles would say, even as they poured a tumbler of Thums Up or Campa Cola. “So much for the wisdom of one’s elders.”

We have no evidence either way on growth, and we will not guess. What is certain is that tea contains caffeine, as do many colas, so the sensible step is to ask your child’s doctor how much caffeine suits them.