Research and Musings on Brewing the Least Toxic Cup ‘O Tea

Jan 25, 2024

AVFC tea


EDITOR’S SUMMARY: It wouldn’t be the first time you sat down to enjoy a food or beverage you were sure was “healthy,” only to stumble upon questions challenging what you thought was true. In the case of tea, a variety of elements are at play that influence the quality and health value of your brew. The good news is that knowledge is queen, and there are multiple, non-complicated options to aid you in making and drinking the healthiest tea you can imagine.


Written by Tracy Reilly
Edited by Nicki Steinberger, Ph.D.


So you’ve cleared your tea stash of all but the organics. You should be all set, right? Not necessarily. Making a healthy cup of tea isn’t quite so straightforward. Between the actual leaves, and the brewing method you choose, a wide range of toxins can sneak into what’s intended to be a healthy, relaxing hot cup.


Tea is the most popular beverage in the world after water, and given its endless variety of flavors and impressive health benefits, it’s no wonder. Tea contains polyphenols, whose beneficial properties include fighting against free radicals that can damage your cells, as well as keeping your inflammation response in check. Preventing chronic inflammation keeps your body from putting itself in a state of high-alert or repair when unnecessary—a process that can lead to conditions such as arthritis and Alzheimer’s disease.  


These polyphenols add something else to tea that you might find less appealing: bitterness. That’s where amino acids come in, offsetting the bitterness with their sweet or savory taste, and providing the building blocks of proteins essential to life. Researchers have found up to 35 amino acids in tea; the primary one being L-theanine, which has been found to help with everything from sharpness of the mind and alertness, to the other end of the spectrum: deep, solid sleep, relaxation, and stress relief.


If you’ve turned to tea for its health benefits, you’re well-aligned with the ancient wisdom behind this flavorful infusion. Originating in the 2000s B.C. in China, tea was first used for medicinal purposes. For centuries, people simply poured boiled water over leaves for whatever ailed them, and of course, for the taste. The Chinese believed that tea, typically green tea, aided in digestion, hence the cultural tendency to consume it after eating. It’s also long been considered helpful in both detoxification and increasing mental acuity. 


Other cultures also turn to tea for health benefits. From “Tea Culture and History”:


“In Ayurveda, an ancient Indian healing system, different types of tea, including ginger tea and tulsi tea, are recommended to balance the body’s doshas [unique constitutions or life energies] and alleviate various ailments. Additionally, in Japanese traditional medicine, tea, especially matcha, is valued for its calming and revitalizing properties, and is often used as a stress-relieving tonic.” 


Ancient brews were generally made with loose leaves in pots. It wasn’t until 1900 or so that tea bags arrived on the scene … accidentally, as it happened. From Time, “A Brief History of the Tea Bag”:


“American tea importer Thomas Sullivan shipped out samples of his product in silk pouches in 1908, not intending his customers put them directly in the hot water that way, but some tried it and asked for more of the same.” 


Since that happy accident, they’ve remained a popular delivery method for this beloved beverage.


AVFC tea bags

One Lump or Two? How ’Bout 11 Billion?

If you’re a tea drinker whose ritual includes a tea bag, recent research suggests scrutiny before pouring your next brew. This is to ensure you’re not also getting a big ol’ gulp of microscopic plastic particles. In 2018, the tea world was taken aback when scientists at McGill University in Canada found a great deal of plastic released with each cup of tea. From McGill: Newsroom Institutional Communications, “Some plastic with your tea?”:  


“… a single plastic tea bag at brewing temperature released approximately 11.6 billion microplastic and 3.1 billion nanoplastic particles into the water. These levels were thousands of times higher than those reported previously in other foods.” 


While science is in the early stages of discovering all that microplastics might do to your body, studies have indicated possible harms in multiple categories—from digestive to respiratory, and the most evidence-heavy and concerning: reproductive. 


For men, microplastics can affect both the quantity and quality of sperm, as well as testicular health. Plastics can act as endocrine disruptors (EDCs)—chemicals that mimic, block, or disrupt your hormones. Sperm appear to be especially sensitive to these troublemakers, with scientists finding that greater exposure to EDCs can decrease male fertility. 


As for pregnant women, babies, namely in the first trimester, undergo very time-sensitive hormonal gender development. This is an issue that greatly concerns Dr. Shanna Swan, a professor of environmental science and public health at Mt. Sinai Medical School. Swan comments on lifestyle factors contributing to the worldwide drop in fertility. Cited from “How plastics are making us infertile — and could even lead to human extinction”: 


“[Those factors] haven’t been increasing at overall the same rate, whereas the production of chemicals–and particularly the production of plasticizers and plastic products–has been actually even faster than the 1% per year [decrease in fertility]. So it’s actually been exponential.”


Whether or not fertility is on your radar, having a plastic-free, nontoxic “cuppa,” as they say in the UK, is likely a preference. So how can you tell which teas use plastic-derived bags? Those silky, pillow-like tea bags are the easiest to spot and some of the worst offenders. You may find their luxurious look appealing, and their design does allow more room for your tea leaves to expand. The downside is that they usually “rely on polypropylene fibers embedded in the outer layer to heat-seal the edges shut.” This ensures the bag won’t fall apart upon contact with boiling water. 


If it’s not an easily-spotted silky sachet, it can be harder to discern. Some say you can try ripping a tea bag to verify it’s paper, and it is true that if a bag is difficult to tear, it’s likely due to plastic composition. But hold on … even bags that tear like paper may bring trouble to your brew. Some paper bags are bleached to achieve a clean, white appearance, potentially leaving dioxin in the paper that can leach into your teacup. Dioxin is considered toxic and unsafe in any amount, as it can cause cancer, as well as reproductive and hormonal issues. 


There are some tea bags that are bleached without chlorine products. To find them, look for “TCF” (Totally Chlorine Free) certification by the Chlorine Free Products Association (CFPA), or call your favorite tea company and ask about their bleaching practices.


Other paper-based bags may contain a plastic component called epichlorohydrin, a substance used to strengthen paper tea bags. When epichlorohydrin comes into contact with water, it hydrolyzes to 3-MCPD, a “likely carcinogen,” by FDA standards. The amount of epichlorohydrin that’s actually left in a brewed cup of tea falls well under EPA allowable limits, but any amount of a likely carcinogenic substance doesn’t belong in your body. 


Beyond epichlorohydrin, many paper-based bags are also sealed using the polypropylene, a heat-resistant plastic. Between such components, it’s no wonder that “on average, tea bags are made up of 20-30% plastic.” On top of the health concerns of microplastics in your tea bags, there’s also the environmental impact. Worldwide tea consumption is estimated at a whopping 18–20 billion cups a day! Asia leads the world in tea production and consumption, and although most Asian cultures brew with teapots and loose leaves, tea bags are widely used in other tea-loving countries. 


In the U.S., 71% of tea drinkers brew mostly or exclusively with bags, and in the U.K., that number jumps to 96%. This creates a mind-boggling amount of potential nonbiodegradable waste from the world’s second most popular beverage.


A Couple Rungs up the Ladder

Similar to how companies work to minimize plastics by coming up with biodegradable or compostable plastic bags for retailers like grocery stores, some tea companies now use bags made of polylactic acid (PLA). While still a type of plastic, it is a step in the right direction in that it comes from renewable resources, such as cornstarch or sugarcane. It is completely biodegradable, which may leave you wondering … then what’s the catch? 


The catch is two-fold. First of all, many PLA products are made from corn—up to 92% of which in the U.S. is genetically engineered (GE). Concerns about GE foods include potential toxicity, immunosuppression, and allergenicity among others. Second, while PLAs are biodegradable, the fine print is that under natural conditions, it would take somewhere in the realm of 80 years to fully break down.


This is where it’s important to distinguish between compostable and “home compostable.” If a tea bag is simply labeled “compostable,” it likely means industrially-compostable. This requires specific temperatures, sunlight, and air exposure to fully decompose. If you find a tea branded “home compostable,” the components should properly break down in the conditions of your home compost.


If you’re looking for easily-accessible brands that use plastic-free bags, some of the most popular are Traditional Medicinals, Numi, the Republic of Tea, and Yogi. Some brands such as Numi, Arbor Teas, and Pukka are not only plastic-free, but home compostable. 


Celestial Seasonings, one of the most popular brands in the U.S. (whose bags tear easily), states that they primarily use abaca, a plant-based fiber. This sounds well and good, but it turns out they also include food-grade polypropylene that’s BPA- and BPS-free (bisphenol A and bisphenol S—industrial chemicals) If you ask for polypropylene-free bags, they’ll point you in the direction of their TeaWell line, or their organic Canadian teas. 


AVFC toxins in tea

Saying Goodbye to a Favorite Tea? Not So Fast …

Bummed that a tea you love comes in packaging you don’t? Using your own fillable bag—disposable or reusable—can be a great way around that. Because the concern with plastic is upon exposure to heat, if you simply cut open the bag of the tea you love and dump it into your own plastic-free bag, you can brew away without boiling water contacting the prepackaged bag. 


Now depending on the manufacturer’s sealing method, it’s possible the tea leaves could have been exposed to heat in that process. Although there are no studies on it, the speed of heat sealing is extremely rapid compared to the prolonged contact of a tea bag steeping in boiling water. Such brief exposure may possibly be a negligible risk. 


If you like the ease of disposable bags, look for unbleached ones that aren’t corn- or sugar cane-based to avoid those sneaky types of plastic under the guise of compostability. If you’re feeling ambitious, you can make your own bags. Just be selective about the fabric you choose, since chemicals in the fabric could come out in your cup. Hemp or organic cotton make good choices, and can also be purchased as reusable bags if you’re less crafty. 


AVFC tea plantation

It’s in the Soil

While the bulk of this story focuses on brewing and tea packing production, under the realm of “nontoxic,” it would be careless to not mention heavy metals and pesticides in the leaves themselves. A more thorough investigation of the plants specifically will be featured in a future article.


Therefore, the last piece of the least-toxic-brew puzzle may surprise you: Tea leaves, even organic varieties, often contain heavy metals, including lead, arsenic, aluminum, and mercury. From J. Toxicol, “The Benefits and Risks of Consuming Brewed Tea: Beware of Toxic Element Contamination”:


“Acidic soil may result in excess available aluminum and fluoride. An acid or alkali soil pH also enhances leaching of toxic heavy metals from the soil. Increasing pH with soluble calcium would reduce the absorption of fluoride. Environmental pollutants such as fluoride and aluminum have been found in tea in part due to the tea plants absorption and deposition and concentration of these compounds in the leaves. 


The drinking of more than 5 liters of tea per week may result in dental or skeletal fluorosis. Mercury, lead, arsenic, and cadmium as well as other toxic elements have been found in tea leaves as described in the literature. Lead, arsenic, and cadmium have also been found in brewed black tea.”


Because tea plants have a high vulnerability to pests, there is a heavy use of synthetic pesticides, including “organochlorines, organophosphates, carbamates, and pyrethroids.” This results in chemical residues transferred from the soil and spray to the tea leaves, and is a major cause for concern. From ScienceDirect: Food and Chemical Toxicology, “The bitter side of teas: Pesticide residues and their impact on human health”: 


“One of the problems related to tea culture is the short interval between pesticide application and harvesting. Compared to other fresh leaves, tea leaves are manufactured directly after harvest without a rigorous washing process. Pesticide residues tend to concentrate on these leaves over time, becoming a problem for tea consumers.”


“Therefore, it has become essential to explore eco-friendly disease management strategies to reach the goal of sustainability in tea cultivation (Chandra et al., 2017). In this context, integrated pest management (IPM) represents an effective tool to decrease chemical pesticides’…”


Fortunately, you can minimize the load of these elements in your cup by minding the brew time. Researchers studying tea contaminants measured toxins after steeping for 3 minutes versus 15 minutes, and found that the longer infusion increased the amount of toxicants. Therefore, it’s best to limit your steep time to three minutes.


If you want to get really precise with timing, beyond the three-minute rule, scientists from Northumbria’s School of Life Sciences in the UK (and who would know better?) got down to specifics. They found that to achieve the ideal cup of tea, you should steep the tea (they tested with bags) in boiling water for two minutes before removing the leaves or bag. Then add milk and wait six minutes, or skip the milk, and wait until the tea temperature drops to 140 degrees—“the optimum temperature for the flavors to flow.”


A friendly reminder: Those two-to-three minutes go by awfully fast, so especially if you’re using a brew-on-the-go cup, keep an eye on the clock, or better yet, set a timer. That goes double if you’re using a classic stainless steel ball infuser, and are sensitive to nickel, since stainless steel can leach nickel if left brewing for too long.


AVFC brewing tea

There’s Got to Be a Better Way 

Know where your tea comes from. This may be easier said than done, but your effort is well worthwhile. There are tea plantations in the Southern U.S., as well as Oregon and Hawaii. Get on the phone and ask questions—”Do you use pesticides? Not sure? Can you please ask someone who would know?” If you leave the call with knowledge about a farm’s growing practices that meets (or comes close) your standards, that’s a win. Purchase organic only, although that won’t guarantee your leaves are free of heavy metals. Alternatively, consider growing your own.


Back to brewing: If you decide to ditch tea bags altogether, and give whole, loose-leaf tea a shot, your body, including your tastebuds, may thank you. A tea’s flavor comes not just from the temperature of the water and duration of steeping, but from how much of the surface of the leaves are exposed to the water. 


Rather than using a tea bag where you’re getting tiny bits, essentially leftovers, of crushed tea leaves (called “dust” or “fannings”—file that one away for trivia night), if you’re using whole leaves, you can expect more nuanced flavors and possibly more antioxidants. It can be cost-saving, too, since whole, loose tea leaves may be reused multiple times. Making loose-leaf or whole-leaf tea can be as simple as measuring out your desired amount, and dumping the leaves right into your freshly-boiled water. When your leaves are done steeping, you can discard the leaves into the trash or compost without worrying about sneaky microplastics hitching a ride.


On the bagless front, there are all sorts of brewing options to explore: from classic stainless steel infusers to teapots with built-in infusers, and even travel mugs that boast built-ins. These contraptions are especially helpful when preparing herbal teas like chamomile, whose flowers are small and unruly to try to scoop out of a pot or cup. There’s no shame in staying conventional with a classic teapot, or you can explore charming options like the Japanese Kyusu, a teapot with a built-in filter and spout on the side for easy pouring. 


One simple down-to-earth method calls for preparing your tea with mason jars. Gather 2 quart-size jars (32 ounces each), and boil your water. Place your tea leaves in one jar (the amount varies depending on your individual preference, but generally a few tablespoons will do), and a strainer over the top of the other jar. Pour your boiling water over the leaves to the likes of 12 to 16 ounces. Let it sit for a couple minutes, then pour through the strainer into the other jar. Now you have a beautiful cup of tea, and a creative process from start to finish. In addition, your leaves can be reused for a second serving.


If loose-leaf brewing isn’t your speed, but you still want to avoid the concerns that come with bags, there are currently several companies selling tea that has been compressed into dissolvable tablets or crystals. This offers the convenience and portability of a tea bag without the waste. 


Although there’s no avoiding toxins in the modern world, when it comes to drinking tea, there are simple ways to minimize your exposure, while reaping the medicinal and mental health benefits. Being selective about your tea choices—from sourcing to brewing methods—is one such way, and fortunately, in that arena, the possibilities are almost as endless as the flavors of tea.




Published on January 25, 2024.


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