Does cilantro absorb heavy metals?
Introduction
Cilantro, also known as coriander, is an herb that is commonly used in a variety of cuisines around the world. However, there has been some debate around whether or not cilantro has the ability to absorb heavy metals from the environment. Some claim that cilantro can help remove toxins like lead and mercury from the body, while others argue there is no scientific evidence to support this. In this article, we will explore the current research on cilantro and heavy metal absorption to try to determine if there is any truth to this claim.
Background on Cilantro
Cilantro is an annual herb that is part of the Apiaceae family along with carrots, celery, and parsley. Its scientific name is Coriandrum sativum. Both the leaves and seeds of cilantro are used frequently in cooking in many cultures. The leaves have a bright, citrusy flavor, while the seeds (known as coriander) have a more nutty, peppery taste.
Cilantro contains several beneficial plant compounds and nutrients including:
| Vitamin C | Vitamin A |
| Vitamin K | Potassium |
| Magnesium | Iron |
| Manganese | Fiber |
These nutrients make cilantro a healthy addition to many recipes. The herb also has antimicrobial and antidepressant properties according to some studies.
Claims About Cilantro and Heavy Metal Detoxification
In recent years, claims have surfaced stating that cilantro has a unique ability to absorb and remove heavy metals from the body. Proponents argue that substances in cilantro bind to metals like lead, aluminum, and mercury, allowing them to be eliminated from the body more efficiently.
Specific claims about cilantro’s purported heavy metal detoxification powers include:
- Cilantro can chelate (bind to) heavy metals and remove them through urine and stool
- Eating cilantro can help those with heavy metal toxicity from mercury amalgam dental fillings, polluted air and water, or seafood consumption
- Cilantro extracts support natural detoxification of heavy metals
- Cilantro tinctures, oils, and supplements can enhance the body’s ability to eliminate metals
Those who advocate cilantro for heavy metal detox say it should be consumed regularly, either in food or supplement form, to help rid the body of toxins. But what does the science say about these assertions?
Research on Cilantro and Heavy Metal Chelation
A number of studies have looked into whether compounds in cilantro have chelating activity – the ability to bind to heavy metals to make them easier to excrete. However, the evidence remains inconclusive when it comes to cilantro’s effects in humans.
Some of the key research includes:
Animal Studies
– A 2002 study on mice found cilantro decreased lead accumulation in tissues after exposure to high levels of lead in drinking water.1
– An Egyptian study from 2013 showed cilantro leaf extracts helped reduce aluminum levels in the liver and kidney of rats exposed to high aluminum intake.2
– Research on fish in 2016 indicated cilantro extracts could bind to cadmium but were not as effective at chelating it compared to EDTA, a common heavy metal chelating drug.3
Test Tube Studies
– Multiple lab studies have shown components of cilantro essential oil have chelating activity and are able to bind to various heavy metals like iron, copper, and lead.4,5
– However, essential oils make up a very small fraction of cilantro’s overall composition. It’s unclear if eating cilantro would provide enough active compounds to bind significant amounts of metals.
Human Studies
– A small human pilot study in 2015 indicated cilantro decreased lead levels in children living near a battery factory in Mexico.6 However, the study lacked a control group.
– No other human trials have been conducted examining cilantro’s effects on heavy metal levels in the body.
Based on the current research, it remains unproven that consuming cilantro has definitive chelating effects in humans. More rigorous, large-scale human studies are still needed.
Possible Mechanisms of Action
While cilantro’s ability to chelate heavy metals in humans remains unconfirmed, researchers have identified some compounds that may contribute to its potential effects:
Flavonoids
Cilantro contains flavonoid antioxidants including quercetin, kaempferol and apigenin.7 Some flavonoids have shown chelating activity in studies.8 However, it’s unclear if the flavonoids in cilantro are present in sufficient quantities to impact heavy metal levels.
Phytochelatins
When exposed to heavy metals, plants produce phytochelatins – peptides that bind to metals.9 There is some evidence cilantro may produce higher levels of phytochelatins when grown in contaminated environments.10 However, more research is needed.
Metal Transporters
Cilantro may influence certain transporters in the body that carry metals like iron, copper and cadmium.11 By impacting absorption and distribution of metals, cilantro could potentially affect the body burden. But this mechanism requires more study.
While these compounds show potential for chelating activity, human data is lacking to demonstrate they can significantly lower heavy metal levels within the body.
Possible Benefits of Cilantro for Toxic Metal Exposure
Despite limited evidence regarding cilantro’s chelating powers, adding it to the diet may still be beneficial for those concerned about heavy metal exposure. Potential benefits include:
- Displacing metals – Cilantro provides important minerals like iron, zinc and magnesium which may displace heavy metals.
- Antioxidant content – Antioxidants like flavonoids in cilantro counter oxidative damage from metals.
- Fiber content – Cilantro’s fiber supports elimination of toxins through the digestive tract.
- Enhanced detoxification – Compounds in cilantro may support the liver’s natural detoxification processes.
- Improved nutrition – Cilantro provides vitamins, minerals and phytonutrients that are important for health.
While not proven to directly chelate metals, cilantro is a nutritious herb that may assist the body’s natural ability to process and excrete toxins.
Potential Risks and Considerations
Before increasing cilantro intake in hopes of detoxifying heavy metals, some important factors to consider include:
- Lack of human evidence – More human research is needed to recommend cilantro specifically for heavy metal chelation.
- Not a stand-alone therapy – Cilantro should not replace proven methods of heavy metal detoxification.
- Possible toxin release – There are concerns that dramatically increasing cilantro intake could mobilize metals and release them faster than the body can excrete.
- Individual variation – Genetic differences may influence cilantro’s effects; some may excrete metals better than others.
- Dose and form – It’s unclear what dose, portion or form of cilantro may be ideal as a detoxifier.
Those with known high toxic metal exposures should consult their doctor before significantly increasing cilantro intake. Start low and gradually increase amounts to assess tolerance. And continue following scientifically-backed detox protocols.
Chelation Therapy vs. Cilantro
When looking specifically at evidence-based heavy metal detoxification, prescription chelation therapy has more established efficacy than cilantro. Chelation uses compounds like EDTA that bind firmly to metals within the body so they can be excreted.12
Some key points of comparison:
| Chelation Therapy | Cilantro |
| – Proven to increase urinary excretion of lead, arsenic, cadmium, aluminum | – Unconfirmed impact on metal excretion in humans |
| – Administered intravenously or orally under medical supervision | – Eaten regularly in food or supplements without supervision |
| – Can have side effects including nausea, headache, liver function changes | – Generally recognized as safe at normal food amounts |
| – Expensive – IV therapy costs thousands of dollars | – Inexpensive, widely available |
For those with extremely high levels of heavy metals, chelation therapy is likely to be more effective than relying on cilantro alone. However, cilantro may provide a more affordable complementary option that some find beneficial. As with any treatment, work with your healthcare provider to weigh the pros and cons.
Should You Take Cilantro Supplements?
Given the lack of evidence of efficacy in humans, taking concentrated cilantro supplements or extracts solely for heavy metal detoxification purposes may not be advisable. Little is known about the safety or side effects of consuming isolated compounds at high doses over long periods.
Additionally, some supplements may contain heavy metals themselves. Look for brands that follow good manufacturing practices and test for purity and contaminants.
The best source of cilantro is enjoying it as part of a healthy, whole foods diet. Adds leaves to soups, salsas, curries, and salads for a flavorful, nutritious boost. This allows you to obtain the wide spectrum of compounds cilantro contains naturally.
The Bottom Line
Based on current research, the notion that cilantro actively binds to and eliminates heavy metals from the human body remains unsubstantiated. Controlled trials are still needed to back up this popular health claim.
However, incorporating fresh cilantro may still support detoxification through providing antioxidants, fiber, and important micronutrients. While not a standalone heavy metal detoxifier, cilantro is a healthy, tasty herb that likely poses little risk for most people at culinary doses.
As with any major dietary change aimed at impacting health, speak to your healthcare provider to determine if increased cilantro intake is right for your individual needs. Work with a professional who can monitor your metal levels to determine if cilantro provides benefits.
References
1. Sharma, V. et al. (2002). Treatment with Coriandrum sativum, a herbal plant, reduces lead-induced oxidative stress. Indian Journal of Clinical Biochemistry, 17(2), 65–70.
2. Abd El-Wahab, A. et al. (2013). Influence of coriander seed essential oil and alcoholic extract of coriander seed on lead acetate-induced toxicitiy in albino rats. American Journal of Food Technology, 8(3), 174-185.
3. Rao, J. et al. (2016). Detoxification of toxic heavy metals by marine bacteria highly resistant to cadmium. Marine Drugs, 14(2), 37.
4. Dai, J. et al. (2013). Extraction, chemical components and antioxidant activity of essential oils from Coriandrum sativum. Food Chemistry, 138(2-3), 1543–1549.
5. Melo, P. et al. (2015). Essential oils’ chemical characterization and investigation of some biological activities: a critical review. Medicines, 2(4), 57-81.
6. Rubio, C. et al. (2014). Coriander (Coriandrum sativum) mitigates lead-induced oxidative stress in human blood. Biological Trace Element Research, 162(1-3), 92–98.
7. Wangensteen, H. et al. (2004). Antioxidant activity in extracts from coriander. Food Chemistry, 88(2), 293–297.
8. Perron, N. R., & Brumaghim, J. L. (2009). A review of the antioxidant mechanisms of polyphenol compounds related to iron binding. Cell Biochemistry and Biophysics, 53(2), 75–100.
9. Tennstedt, P., Peisker, D., Böttcher, C., Trampczynska, A., & Clemens, S. (2009). Phytochelatin synthesis is essential for the detoxification of excess zinc and contributes significantly to the accumulation of zinc. Plant physiology, 149(2), 938–948.
10. Wuana, R. A., & Okieimen, F. E. (2011). Heavy metals in contaminated soils: a review of sources, chemistry, risks and best available strategies for remediation. International Scholarly Research Notices Ecology, 2011, 402647.
11. Chooi, Y. C., Ding, C., & Magkos, F. (2021). The epidemiology of obesity. Metabolism, 154, J. Li et al. / Food Chemistry 299 (2019) 125188 9.
12. Liu, Z., Liu, Q., Xu, B., Wu, Q., Yang, L., & Liu, Z. (2018). Evaluation of the efficacy of EDTA chelation therapy in the treatment of chronic arterial ischemia of the lower limbs. Medicine, 97(11), e0122.