In recent years, green juices have become the poster child for the wellness movement. From casual health-conscious consumers to fitness buffs, everyone seems to be jumping on the green juice bandwagon. If you’re a green juice fan, your recipe probably includes a combination of green leafy vegetables, cruciferous vegetables, and grasses, among other ingredients. Those who prefer speed and convenience can find a diverse array of green powders to mix into water or other liquids. So you might be thinking — these are all healthy ingredients, so green juice must be healthy, right? Well, not necessarily. Some of the star superfoods in green drinks, like kale and broccoli, maybe hiding a dangerous secret: high levels of heavy metals, particularly thallium.
What is Thallium?
Thallium is a soft, malleable heavy metal discovered by Sir William Crookes in 1861. It is colorless, tasteless, and water-soluble; thus, it was once a favored homicidal poison.
Historically, thallium was once commonly used as a rodent or ant killer, but its use has been banned in the United States and many other countries due to accidental poisoning. Small amounts of thallium are still used industrially, for purposes such as:
- Optical lenses
- Green-colored fireworks
- Semiconductors
- Low-temperature thermometers
- Imitation jewelry
Thallium can also be found naturally in the environment, although usually at low concentrations.
However, emissions from natural or human causes can lead to increased levels of the heavy metal in the environment, where it can eventually pose a major threat to terrestrial, aerial, and aquatic systems.
High concentrations of thallium in soil poses a unique threat due to possible uptake and storage by plants. As a result, thallium can enter the food chain and accumulate in our bodies, causing severe health problems and even death. Of particular concern is that high thallium concentrations have been found in drinking water and many green vegetables, some of which include those we’ve come to know as “superfoods,” such as:
- Green cabbage1
- Kale2
- Broccoli
- Cauliflower
- Mustard
- Collard greens
- Brussels sprouts
- Turnip (greens and roots)
The average human diet contains approximately 2 ppb thallium3, most of which is secreted in urine and feces. However, eating and juicing massive amount of kale day in and day out could contribute to thallium toxicity. This means that if you drink the same green juice or smoothie daily, you may want to reconsider your habit.
Symptoms of Thallium Poisoning
Needless to say, thallium is highly toxic. Its toxicity is known to be even higher than mercury, cadmium, and lead. Unfortunately, victims of thallium poisoning usually are not aware that they have consumed or have been exposed to the heavy metal. Furthermore, thallium poisoning is rare and published data is limited, which means it is often misdiagnosed until it is confirmed by urinary and blood tests, resulting in delay of treatment.4
What we do know is that thallium is quickly and almost completely absorbed via several pathways, including eyes, ingestion, inhalation, and skin exposure. Upon absorption, thallium spreads widely to multiple organs in a distribution pattern similar to that of potassium ions. Therefore, thallium deposition occurs in all tissues and is most highly concentrated in neuronal, heart, liver, kidney, and dermal tissues.5
Due to multiorgan involvement, the symptoms of thallium intoxication are nonspecific and variable, depending on the dose and route of exposure. Thallium poisoning commonly occurs in three stages.
Gastrointestinal phase:
Thallium and its salts are corrosive to the gastrointestinal mucosa, leading to the following symptoms:
- Severe abdominal pain
- Cramping
- Nausea
- Vomiting
- Diarrhea, followed by constipation
This gastrointestinal phase may begin immediately after ingesting a large dose of thallium or 24 to 48 hours after smaller ingestions. These symptoms can last for 12 to 96 hours, and diarrhea is usually followed by several days of constipation. In some cases of chronic thallium poisoning, patients may experience few or no gastrointestinal symptoms.
Neurological phase:
This phase is characterized by painful, rapidly ascending sensory neuropathy. It may be accompanied by motor neuropathy. Patients commonly complain of the following:
- Severe pain
- Burning feet
- Difficulty walking
- Skeletal muscle cramps
- “Stocking-glove” numbness and tingling
- Vision changes due to dysfunction of cranial nerves
- Nystagmus (involuntary eye movement in which the eyes move rapidly from side to side, causing reduced vision and depth perception)
- Confusion
- Anxiety
- Tremor
- Ataxia (impaired coordination)
- Altered mental status
- Seizures
- Coma
- Short-term memory and cognitive deficits
The neurological phase may begin 2 to 5 days after ingestion, although it may occur sooner after a massive exposure.
Alopecia phase:
Alopecia, or hair loss, is a hallmark of thallium poisoning and can occur 2 to 3 weeks after the other symptoms begin. Complete hair loss can occur within a month of exposure.
Other Symptoms of Thallium Poisoning
While alopecia and neuropathy may be the only symptoms present in some patients, others may also experience the following:
- Pneumonitis
- Acute respiratory distress syndrome (ARDS)
- Pulmonary edema
- Respiratory depression
- High blood pressure
- Abnormal heart rhythm
- Rapid heart rate
- Headaches
- Loss of appetite
- Dry and crusty scaling of skin
- Inflammation of the mouth, lips, and gums
Severe cases of thallium poisoning can cause death in 5 to 7 days following exposure. The lethal dose of thallium in humans is reported to be 10 to 15 mg/kg, but deaths have been known to occur in adults with doses as low as 8 mg/kg.6,7
5 Ways to Minimize Thallium Exposure
- Diversify your diet: The fact is, there is no “magic bullet” that prevents diseases and/or aging. Instead of sticking to just 2 or 3 vegetables, try to add some variety to your vegetable consumption.
- Switch to stems and roots: The highest levels of thallium are found in plant leaves and seeds, while stems and roots have shown much lower levels. Switch out your kale and cabbage for radishes and wasabi (root) to minimize your thallium exposure.
- Use soil rich in potassium: Heavy metals and nutrient minerals compete with one another for absorption. Therefore, if you grow your own vegetables, adding potassium to the soil can suppress uptake of thallium.8
- Prioritize soil ecology: Potassium must first be solubilized before it can be taken up by plants, i.e., no amount of potassium supplementation will increase the uptake of the mineral without help. Potassium solubilizing microorganisms (KSMs) can help convert insoluble potassium to its soluble version.
- Supplement your diet: Potassium supplementation has been shown to mobilize thallium from tissues in cases of severe thallium intoxication.9 If you feel that you are experiencing symptoms of thallium intoxication, talk to your doctor about adding a dietary potassium supplement. Selenium has also been shown to counteract the toxicity of heavy metals like thallium.10
Should You Stop Drinking Green Juice?
With that being said, should you stop drinking green juice? Green juices may not be as healthy as we may have believed, and I would not recommend anyone rely on them as the primary source of vegetables. Still, I think the bigger concern here is that too many Americans still don’t eat enough green leafy vegetables. Rotate and diversify your green superfoods, and you’ll be able to continue enjoying their health benefits.
Now it’s time to hear from you. Have you experienced any odd symptoms after consuming green juices or smoothies? Are you surprised by the presence of heavy metals in kale and other superfoods? Share your stories or thoughts in the comments below!
References
- https://www.ncbi.nlm.nih.gov/pubmed/26067081
- https://poshretreat.org/2015/10/20/kale-and-thallium-insights-from-a-permaculturegardenernutrition-pro/
- https://poshretreat.org/2015/10/20/kale-and-thallium-insights-from-a-permaculturegardenernutrition-pro/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1742612/pdf/v079p00103.pdf
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5449837/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550187/
- https://www.ncbi.nlm.nih.gov/pubmed/22865288/
- https://link.springer.com/article/10.1007/s11356-014-3490-7
- https://www.ncbi.nlm.nih.gov/pubmed/9022660
- https://www.ncbi.nlm.nih.gov/pubmed/1304229
Is it the same for organic vegetables? Or just those grown in non-organic, nutrient-depleted soil?
Yes, organic is grown without pesticides but can still absorb thallium from the soil
I had forgotten about Thallium in vegetables. Thanks for the reminder and this helpful article !! Hope your day goes well !
This seems ridiculous to me. Who literally eats the massive amounts they would need to to actually get this? Why even put it out there? There are way more ppl that aren’t eating or drinking greens compared to those that eat too much.
I wish it were ridiculous 😔… absorption of thallium from the soil by kale and other veggies is a real issue
This is from the widely respected naturopathic journal, The Townsend Letter back in 2015. I did a routine test for heavy metal toxicity and my Thallium levels were noticeably high. I was drinking organic, local green juice several days a week, not excessive amounts. So, it doesn’t seem ridiculous to inform people about this issue. It seems current and necessary. The bigger question is: how is this getting into our organic vegetable farms and soils? Thallium is a by-product of coal ash. There’s no coal ash being produced in the Bay Area in Marin and Sonoma counties, so how is this stuff getting here?
http://www.townsendletter.com/Jan2016/thallium0116_2.html
You haven’t mentioned whether the issue is mostly in consuming non-organic vegetable juice
The issues is in organic greens as well… organic means no pesticides or chemicals are used in the growing process but kale and other greens pull thallium from the soil, organic or no.
Hi Dr. Jill,
I love my green smoothies! Is the danger also an issue with organic greens? I only consume organic greens.
Thank you!
yes, organic greens can also absorb thallium from soil and there is no testing or regulation that I know of…
Thanks for the article. However, IMHO, more info is needed. What about red cabbage, bok choy or swiss chard? Are they ok? Would not would not recommend anyone rely on these veggies as the primary source of vegetables? This sounds like one would be ok if not juiced, but eaten as a regularly cooked meal – but presumably this is not the case.
Wonderful work you do! Thanks for this article!
This may be of use https://www.atsdr.cdc.gov/toxprofiles/tp54-c5.pdf
Is this the case even if the veggies are organic? Thanks.
Does this uptake occur when consuming organic greens?
Yes, organic is grown without pesticides but can still absorb thallium from the soil
Can you at least put a general ranking of best to worst veggies for juicing? Understood that this will only be an estimate, but better than nothing…
The heavy metals in green drinks: Does this mean also the organic ones have the thallium, or maybe organic ones aren’t even tested for thallium?
Yes, organic is grown without pesticides but can still absorb thallium from the soil and organic certification doesn’t involve testing for thallium that I know of
I have been using a green drink called Kyogreens, and taking about 2 Tablespoons of it per day. It looks like barley and wheat grass, FOS, brown rice, chlorella, and kelp. It is sourced from Japan’s highlands. It is called a unique blend of superfoods. Any thoughts on this? I have been taking for adrenals and has helped with energy levels, but what I read here concerns me.
Yes, I think its important that we ask manufacturers for evidence of quality and purity testing, especially if its something you use daily.
warmly
Dr. Jill
Thank you for the excellent content. It’s very helpful. Between the problem of super high oxalates in spinach, chard, and beet greens, and now the addition of thallium in the lower oxalate greens like kale and mustard, it’s getting tough to fit enough nutrients from greens into the diet.
I know, Lorie! I couldn’t agree more… I think we can continue in moderation and make sure we are getting enough variety.
Is the soil everywhere on earth high in thallium or is there still a part of the world where I can source my vegetables from or move to where this won’t be an issue? Almost all foods have a propensity to sequester certain heavy metals from the land, water and air. How long has this been an issue? When did we first have the tools to start measuring for heavy metals in our whole food supply? I know proper and safe detox is important but I’d still want to minimize exposure as much as possible since I’m genetically poor at it. Thank you for increasing out scientific literacy.
It’s irresponsible to scare people into thinking their green juice is toxic. How many people have been diagnosed as having a thallium toxicity issue directly from drinking green juice? Where is the proof? That should be the first point addressed. Otherwise this article is based on a “possible” correlation that could easily scare people into the wrong direction of staying away from veggies altogether which does much more harm than any good that could come from this click bait post.
You might review the government data here. It is unfortunately a real issue.
vitamin A poisoning?
Does the thallium increase in soil have anything to do with using the end result of sewer waste recycling plants as fertilizer on crop lands? Some cities even give this away for free. I have also heard that some consider the stuff as organic. I seem to remember reading an article about the product being high in heavy metal matter, since humans are Apex predators and much of our diets comes from high level contaminated sources. Even if spread on pasturelands, the animals pastured there would eat and store thallium, that we would end up consuming. Your thoughts on this?
You might find this article helpful – https://www.atsdr.cdc.gov/toxprofiles/tp54.pdf
Thanks for this info as I haven’t heard about this before and I was hooked on green smoothies in the morning especially in the summer. I alternated between kale and spinach as the base since I heard too much of one or the other was not good for you. But what happened to me is kidney stones. All those vegetables are high in oxalates and can cause kidney stones. So I had to quit doing that. I have to balance my intake of vegetables between high and low oxalates. Everything I was eating to be healthy and avoid cancer was high in oxalates, i.e. nuts, tea, vegetables, almond milk are a few.
Thank you, Betty!
Thank you for the article! My daughter who began eating lots of cruciferous veggies on an AIP diet is now bald. Heavy metals testing indicated moderate amounts of thallium and she is now doing her best to avoid exposure and safely detox. This is a real issue that can’t be ignored!
Wow, this appears to be a quite a hot-button, emotionally-charged topic for some people based on the responses here! What I took away from the article was that green smoothies made with organic greens are still a great addition to your diet, but just don’t overdo it (probably shouldn’t be having five green smoothies per day) and try to use a variety of different greens rather than the same thing daily.
Thank you Dr. Jill for your great articles! I appreciate your work very much!
Thank you for your kind words and support, Rod!
Thank you, Dr. Jill, for your Green Juice article. The Naturopath, Dr. Peter J. D’Adamo, has warned against consuming raw cruciferous vegetables — kale, cabbage, broccoli, and collards — as they are metabolic supressors. Most people want to boost their metabolisms. Crucifers, as well as all other foods, are recommended based on blood type. Blood type O should avoid cabbage, cooked or raw. As with all foods, check the ingredient list against recommendations for your blood type.