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Cadmium contamination in cacao products


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Meanwhile, I just purchased Earth Circle Organics, Organic Balinese Cacao Nibs:




I haven't been able to confirm this via PubMed, but my understanding is that there tends to be much less cadmium contamination in Bali. (Not sure about lead, but I doubt any place is as bad as Africa -- where the problem mostly arises during processing because of Pb in the air.) I'm going to contact Earth Circle to see whether someone can "obtain the actual numbers"....


Hi Brian, 


I realise I’m very late to this conversation but I was wondering if you ever got any info/actual numbers from Earth Circle Organics about their Balinese cacao?





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  • 5 months later...

Investigating Cadmium Levels in U.S. Cocoa Products  [pdf]



Edward J. Orzechowski   University of Delaware  Thesis  2016


Using JECFA’s [Joint Expert Committee on Food Additives] daily exposure estimate range of 0.005 to 0.39 micrograms per kilogram of body weight, the typical exposure ranges from 0.02 to 1.6% of the PTMI [Provisional Tolerable Monthly Intake]  [...]
From our findings, Table 5 indicates the amount of 20g servings an average adult weighing 70 kg would have to ingest during a one month time period to reach JECFA’s PTMI for cadmium.
Edited by Sibiriak
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Very good Sibiriak, even though data are pretty variable, from Orzechowski's article I was able to determine the maximum amount of Bolivian cacao powder I should eat every day, and that's 40 grams which equals the JCEF PMTI.


Sometimes I go beyond that, so I should watch myself out. 


The fact that data are so scattered doesn't help, but we can get to a reasonable estimate by knowing the harvestign area and the average Cd content.


But at this point what I should really do is to get in touch with the importer and ask for lab analyses. It doesn't help that it's the only unprocessed cacao powder available.

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Costco recently had 24oz. bags of Navitas organic cacao powder in the warehouse where I go. I was so excited I bought 4 of them. On the way home, I remembered having seen this discussion. I was considering taking the cacao powder back to Costco, but, decided to write to Navitas first. I noticed that the bag did not have the same "cadmium causes cancer" warning banner on the bag like the one I bought from another store. My guess was that either the warning was not required in the state where I bought the product, or, that the package warning was not required because levels were below the threshold that would require such a warning. It turned out to be the latter.


Upon further questioning, the person at Navitas told me that the average cadmium level in the Costco product was around 0.04 mg/kg/day, as I recall, which was well below the 0.07 mg/kg/day that would have required the package warning. I deleted the email several weeks ago. But, I think this is an accurate account of the numbers Navitas gave me. Just thought I would update this thread with that bit of info.


I add cacao to my morning yogurt daily, along with ground flax seed and a 25mg tab of zink.

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Thanks beachblue, I'm adding some more threshold values (the WHO value is not clear at the source)


Many health agencies have set exposure standards designed to protect the general public from excess cadmium exposure from various sources.




  • Maximum limit of cadmium in bottled water: 0.005 mg/L.




  • Chronic durational oral minimal risk level (MRL) of 0.1 µg/kg/day of cadmium based on its renal effects.
  • This MRL standard states how much cadmium can be taken in orally chronically without risk of adverse health effects (ATSDR 1999).




  • Food - Reference dose is 1 x 10-3 mg/kg/day (ATSDR 1999).
  • Water - Reference dose for human exposure is 5 x 10-4 mg/kg/day.
  • Reference dose (Rfd) is an estimate of a daily exposure to the general population (including sensitive subgroups) that is likely to be without appreciable risk of deleterious effects during a lifetime (IRIS 2006).


World Health Organization (WHO)


  • Tolerable weekly intake for cadmium at 7�g/kg/body weight/week
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  • 2 weeks later...

I recently ordered from amazon this raw cacao powder, lowfat and unprocessed (as I could verify from teh color and taste).

It's very good tasting and the price is reasonable. I asked for Cadmium analyses and they answered me immediately, unfortunately not having that data:



Hi Mccoy,

PINK SUN test for the full spectrum of pesticides to ensure organic authenticity.   We also have tests for Pb (<1ppm), As (<1ppm) and Aflatoxins (<10ppb), all below lower detection limits.  We do not have on file tests for Cd or Total poliphenols/flavanols/(-)-epicatechin, sorry.

Have a healthy and well 2018!

Kind regards Michael





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That PINK SUN cacao powder certainly looks like a good deal price-wise.   According to their web site  the product is produced in South America,  so chances are it has a decent amount of polyphenols and borderline high cadmium. 


I'm currently using a high-priced organic non-alkalized  cocoa powder +cordyceps and reishi mushroom blend.  The cocoa is sourced from the Dominican Republic, Peru and Ecuador.  A certificate of analysis of one lot claims 0.554ppm cadmium, which is not that low.


It has a rich and bitter taste, which I like to  temper with a bit of  buckwheat honey.  If fact,  I think I'm going to have some now!  It's getting dark and a cold night is coming.

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  • 5 months later...

First, the EU are happily on top of this, and have established limits for cadmium specifically in cacao and cacao products, on top of the maximum levels for cadmium in foods generally that have existed since 2001. Starting on January 1, 2019:

Milk chocolate with below 30% total dry cocoa solids must contain no more than 0.10 mg/kg wet weight
Chocolate with over 30% cocoa and below 50% must have no more than 0.30 mg/kg of cadmium.
Chocolate with more than 50% will have a threshold of 0.80 mg/kg.
Cocoa powder sold to the final consumer typically as drinking chocolate will have a limit of 0.60 mg/kg.

(a mg/kg is the same as a ppm, for all intents and purposes). Additionally, Prop 65 legal settlement is also about to bring in a de facto new industry standard for lead and cadmium in chocolate in California, and therefore likely in the USA. "The settlement establishes complex requirements regarding investigation of both the natural and man-made sources of lead and cadmium in chocolate, as well as evaluation of feasible measures to reduce such levels. This work is to be undertaken by a committee of experts chosen by the initial parties to the settlement, pursuant to a fairly aggressive timetable which can be modified if circumstances so warrant. The expert committee, which must conduct its work on a “consensus basis” rather than by majority vote, also is required to determine the concentration of lead and cadmium in chocolate products, above which a warning is required." But if no conclusion is reached, some default limits will go into effect, depending on the percentage of cacao solids: for products ≥95%, these would beset at 0.800 ppm for Cd and 0.200 ppm for Pb by 7 years after the December 2017 settlement date.
I've gone around and asked a variety of suppliers of organic cacao nibs for CoAs for cadmium and lead in their products, to varying degrees of success — and with some questions about the entire process.
In brief: I contacted six companies and asked them for CoAs for cadmium and lead in their products. One got back to me with a CoA immediately; three got back to me within 36 hours; one said they would get me a CoA, but dragged the process out over three days and ultimately only provided summary information from 2016; and the last one said they would send one after confirming that I was not a competitor, but have not followed up and don't seem to be answering the phone. 
Nuts.com, from whom I've been buying nuts and other products for many years now, were extremely disappointing: I asked them for a CoA, and they initially sent me a booklet on all their quality procedures, including internal GMP and customer complaint procedure. It's good that they have this, but it was not at all what I asked for. I pressed them on this, and was told that "Due to recent changes in our policies and procedures, we do not provide COA's for orders under a certain price point. ... The document you received should contain all the information required by law including our letter of guarantee. In addition, all of our customers are welcome to conduct their own 3rd party testing [!!}" It shouldn't matter if I'm ordering a pound or a metric ton: a responsible and transparent company conducts testing on every batch of raw material that they order, match source material with the lot numbers for their product as sold to consumers, and provide CoAs on request.
Viva Naturals was quite transparent: customers asked questions on their Amazon page in 2015 (twice) and 2017, and in all cases they responded (with specific numbers in 2015, and with their general standard in 2017). I emailed them to ask for a CoA and was promptly sent one: it was a third-party CoA with the lab disclosed as well as a clear published method ICP-MS (AOAC 2013.06), with Cd of 0.53 ppm and Pb of <0.02 ppm.

I also got good results from Terrasoul: asked about Cd by a customer on their Amazon page, they said " We extensively test and 3rd party lab test for heavy metals. These results are available upon request by contacting us through our site." I did so, and was indeed sent a third-party CoA, with method specified (though only to say it was ICP-MS), and similar reasonably low levels (though nominally slightly higher than the forthcoming EU or  Cd — again, see below before freaking o): Cadmium (ICP-MS) 0.824 ppm, Lead (ICP-MS) <0.005 ppm.

I should note that they advertise this to be Criollo cacao, which is supposedly tastier, but has also been reported to have lower phenolic levels than other cultivars.
By phone, Super Good For You Foods said that their Cd and Pb levels were present only at very low trace levels, but  initially refused to send a CoA, on the basis that doing so would reveal their supplier and thus threaten their business. This may be revealing in itself, since the most likely reason a supplier would be on a CoA would be if the CoA were supplied by the supplier, rather than done by an independent lab hired by the purchasing company. After a bit of back-and-forth, they agreed to send me a CoA with the supplier name blacked out. It took a while, for some reason, but they did get back to me by the end of the next day with a CoA — of sorts. The document is clearly not an original, but a summary document, which is not that big of a deal if you are willing to trust that they didn't just make it up. It also says "A representative sample from the lot listed below was used for this analysis," but then under "LOT #" says "Sample"! But it's dated for April, so it's at least current, and the actual information seems good: it has all the info you'd expect to see on a CoA  (other than the circular-reasoning lot number) and some that you wouldn't necessarily expect but are nice to see. In terms of the subject of this post, they report 0.320 ppm Cd and 0.027 ppm Pb, both by ICP-MS (specific methodology not referenced).
Wilderness Family Naturals was a bit of a shaggy dog story. They openly list on their own website:

Raw Certified Organic Cacao Nibs, Fermented
Arsenic <0.049 ppm
Cadmium 0.689 ppm
Lead <0.049 ppm
Mercury <0.02 ppm

Raw Certified Organic Cacao Nibs, Non-Fermented
Arsenic <0.049 ppm
Cadmium 0.689 ppm
Lead <0.049 ppm
Mercury <0.02 ppm

These are not bad numbers, but they're two years old — and they're giving the same numbers for two different products, which is either an error or, um, well ...
So I phoned and asked for current CoAs for both. When I didn't hear back almost 48 h later, I emailed them to follow up. The next day, they sent me links for two files. Unfortunately, they were links to their Slack workspace, which is of course an internal site for which you need an administrator-authorized login, which I didn't have and which I'm sure they'd not've given me. I pointed this out, and their rep apologized and sent me a single image file — with the exact same information already on their website! Pressed on the point, I got "Our most current heavy metal testing for nibs can be found on the website in each product's respective page. This is the only information that we can provide at this time ."
Finally, I looked at Raw Food World. A (former?) vendor had given the following two inconsistent replies to customer questions:

* * * * * * * * * * * * *
What is the cadmium level and when and who tested it?
A: We had it tested against the other top raw cacao products on the market and ours had the lowest lead and cadmium there is.
By EcuadorLiving on December 27, 2015

Q: If the lead and cadmium levels are low why is the california warning sticker on the package? these are the best cacao nibs i have ever had. i would ha
A: This is known as Proposition 65 label required by law.
By EcuadorLiving on July 18, 2017
* * * * * * * * * * * * *
Of course, if they actually had "the lowest lead and cadmium there is," they wouldn't need a Prop 65 label.

Their own website's product page says "it has a very low lead count, unlike many other cacao products on the market today", but nothing about cadmium, and nothing quantifying what a "a very low lead count" is. Despite this, they have a defensive page on Prop 65 with a lot of the usual whining, including the somewhat disingenuous statement that "Proposition 65 contains a unique "citizen lawsuit" provision. That means private citizens can file lawsuits against businesses they claim aren’t fully complying with the law—regardless of whether or not that’s true." Of course, citizens can file lawsuits whether or not their claim is well-founded (and some such suits are indeed poorly-founded), but you only *win* if you have good evidence on your side.

In any case, there's an image on the page that seems to show their cacao nibs to have low lead levels compared to some other foods, though it's per serving side rather than per gram:


A serving is 28 g, so this seems to suggest something like 1 mcg/28 g = 0.036 mg/kg. The Prop 65 "safe harbor" levels (No Significant Risk Levels (NSRLs) for Carcinogens and Maximum Allowable Dose Levels (MADLs) for chemicals causing reproductive toxicity ) are 15 mcg and 0.5 mcg/d, respectively: it appears that even one serving of this product puts one above the MADL, though one would have to take in significant amounts from other sources to reach the NSRL (though other risks for lead exist other than these two). So, yes, they need a warning label.

They proved to be difficult to reach by phone: they were usually either on the phone or only had voicemail, and it's a generic voicemail message at that. When they finally responded, they assured me that they had very low Cd & Pb in their product. To send me a CoA, however, they wanted me to contact them via their online form with an email address (rather than just asking me for such), after which they said they would email me a form to certify that I was not a competitor, upon receipt of a signed copy of which they said they would send a CoA. Now, if they have the data and it's not sky-high, why would it matter if I was a competitor? And why put anyone — especially a potential customer, but even a competitor — through so many hoops? If they have über-low heavy metal levels (in which case, again, they wouldn't need a Prop 65 label), they ought to be proud to send it to anyone who asks: "Take that, Natural Foods Wonderland!!!"
Days and days later, after additional emails and voicemail messages, nothing has been forthcoming.

One more. I didn't contact them, but in response to a customer asking "What is the cadmium and lead levels in the bean and are they less or more than in the powder?", Healthworks didn't actually address the question, but directed them to a gernal statement about cadmium being naturally present in cacao and "at levels low enough for safe consumption according to the U.S. food and Drug Administration's guidelines." They were a bit more transparent but still defensive when asked "Why does this product have california proposition 65 safety warning. are ingredients not listed to require the prop65?" Reply: "Companies are required to place a warning label on any product ... if it exceeds the level that the State has established as risk free for a list of over eight hundred chemicals. ... The lead standard in California is more stringent than what is required at the U.S. Federal level, and by ... Canada and the European Union. A lot of research is being done on why chocolate products can contain high levels of cadmium and sometimes lead. Cadmium is a naturally-occurring element that can be present in soil. This means traces of it will be transferred to crops. Nevertheless, we do routinely have our products tested for heavy metals to make sure they are within the limits set by the FDA."

However, customer reviews for Healthworks say "Consumer lab has just published it's review of cacao products and out of the 41 products they reviewed, Healthworks cacao powder had the 3rd highest levels of cadmium at 24.9 µg per serving." (By kgmedicine on July 17, 2017) and "ConsumerLabs tested these and found high levels of cadmium- 24.9 mcg cadmium per serving (1.8 mcg per g)! ... This is why Healthworks Organic Cacao comes with a Prop65 warning, and other cacao nibs such as Viva do not." (Narrowrd on March 15, 2018)

The Problem with ICP-MS
A significant fly in the ointment of all of this is that the  ICP-MS methods that are apparently widely used for this purpose are apparently not very reliable:

First off, that stands for Inductively Coupled Plasma – Mass Spectrometer.  ... [samples] are sprayed into a chamber containing a Plasma to ionize the metal, the metal ions are introduced Spectrometer and the Masses are Scanned.  The intensity of the mass scan correlates to how much is in the sample.  The sweet thing about an ICP-MS is that the user can decide whether to scan all the masses at once (a “Scan”) or give each mass individual attention.  For scans, a little bit of sensitivity (you can’t see as low) is given up for the sake of time (it is fast, hence the term scan).  Accuracy is usually also given up to some degree ...

[Companies are told by analytical laboratories that they]  can have each analysis (compliance defendable but not stated) for $150 or a whole metals scan (wow, 20 metals!) for $200[, so they usually] takes the scan. ...

Standard laboratory policy in every lab I have ever worked in is that scans can never be used for compliance and that we made sure the customer knew that clearly.  If they needed defendable data they needed an analysis focused on the metal in question, extracted under the appropriate conditions to give the needed results....

[The reported] numbers could be elevated, and that the extracted amount could be much lower. ... [Or much higher] ...  Or there might not be any metal there at all (frankly, more likely).  The issue is you simply don’t know.  Just because you see a number, doesn’t make it real.  You need verification and fast scans just don't provide that..

ICP-MS are often touted as having a huge dynamic range. ... [but that's only true] under certain circumstance ...  One of those circumstances is a clean matrix.  Cocoa and most solids are not clean (like drinking water).  Another condition is not being in scanning mode.  And what may not by apparent by that dynamic range statement is the relationship may not be perfectly linear. ...i.e. twice the amount of metal gives twice the amount of signal [is] mostly true at medium levels, but at very low levels the error can get very large. ...

These can be incredibly small amounts of material and laboratories use reagents (acid and such) that may contain again, incredibly tiny amounts of these substances that can add up in glassware, concentrate in samples as more is added to break down the sample (fats like in cocoa butter usually take additional acid) and the matrix itself can cause extra signal.  Hence the disclaimer that most labs put on scan results. ...

The best situation is that the customer could have just submitted to the lab a sample of the exact extract they wanted to know about since that at the end of the day is the important number.  Not the total number, but how much might be consumed.

Until I see results of significant levels of lead or cadmium in brewed cocoa, analyzed by something other than a quick scan, I’m going to stay in the unalarmed category.

Oh, and I won’t eat 2 kg chocolate a day.

For now, I think it's best to take people having done ICP-MS testing as a sign of someone trying to do the right thing, and that the stuff probably is reasonably good if it comes in the ballpark of the EU standard, but to basically laugh off differences of a few tenths of a ppm between suppliers (which you should probably do anyway, since they're all done at different labs and only one of my three 'hits' above actually tell you they're using a published methodology).

... And the Usual Greger Mendaciousness
I see that Greger has once again taken the opportunity to mislead his readers on a subject of interest (in this case, cadmium exposure) in order to sell them on a vegan diet. He says

Cadmium bioavailability from animal-based foods may be higher than that from vegetable-based foods. There appears to be something in plants that inhibits cadmium absorption. In fact, researchers found when they added kale to boiled pig kidneys, they could cut down on the toxic exposure. Just one tablespoon of pig kidney, and we may exceed the daily safety limit—unless we add kale, in which case we could eat a whole quarter cup. The pronounced effects of the inhibitory factors in kale point out, as the researchers note, “the importance of vegetable foods in terms of prevention of health hazard from [cadmium] ingested as mixed diets in a real situation.”

From reading that, you'd think he was talking about a study that had actually tested "exposure," and that their study involved some semblance of “a real situation.” in fact, this was an in vitro "digestion" model with colorectal adenocarcinoma cells.

He also asserts that "Researchers have concluded: “Even if a vegetarian diet contains more lead and cadmium than a mixed diet, it is not certain that it will give rise to higher uptake of the metals, because the absorption of lead and cadmium is inhibited by plant components such as fiber and phytate.” 
Now, the fact that the quote says "it is not certain" but Greger says "Researchers have concluded" already tells you he's trying to frame something as a more definitive claim than the researchers themselves were making. This might not be that big a deal: sometimes researchers will find evidence of X, but be cautious about drawing a firm conclusion because of the limits of their study (for instance, an associational finding that they don't want to claim is causal without actual controlled experimental data).
But that's not what was going on in this case. Here, when the scientists wrote "Even if a vegetarian diet contains more lead and cadmium than a mixed diet, it is not certain that it will give rise to higher uptake of the metals, because the absorption of lead and cadmium is inhibited by plant components such as fiber and phytate," it wasn't intended as even a tentative conclusion: it was the hypothesis that they were testing — and their results failed to support it! "There was a large inter-individual variation in faecal elimination of lead and cadmium during both the mixed-diet period (range 14 to 118, median 31 micrograms Pb/day; range 4.5 to 21, median 12 micrograms Cd/day) and the vegetarian diet period (range 19 to 136, median 42 micrograms Pb/day; range 6.1 to 24, median 14 micrograms Cd/day).  There was a tendency towards increased faecal elimination of lead and cadmium following the change to the vegetarian diet, but the differences were not statistically significant."
To be fair, there is some evidence that veg(etari)an diets may lower Cd body burden: here and here. On the other hand, in a study in Norway, while "Vegetarians had lower levels of Hg and Sb compared to omnivores ... [with] No differences ... between vegans and vegetarians", the vegetarians' blood cadmium levels were the same or possibly higher than omnivores (1.7 vs. 1.5 nmol/L blood, NS).

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Thanks for your well-researched study Michael.


Since I eat fish frequently (otherwise vegan, no grains diet), I have my blood and urine Hg tested at each

semiannual bloodwork. In fact, my nephrologist does a full heavy metal bloodwork (and urinework).


All heavy metals including Hg, Pb, Cd always come out vanishingly low -- but, surprisingly, As unexpectedly

is always high. My nephrologist has been regularly doingmore comprehensive As testing.


Summary of consistent results: Inorganic As is very low; the one that's high is organic As, which is BELIEVED to be OK.


BTW, IMO the reason why my serum Hg is low (despite fish eating) is that I'm careful which fish to eat. I study

known reults on Hg levels in fish, and avoid those that are high in Hg (e.g., Ahi Tuna -- a No No), and/or at the top of the

food chain (pretty much the same fish).


Fish low in Hg -- and high in fatty acids -- include: most salmon, all sardines (that I know of), and most other samonids.

Of course, farmed fish must be farmed properly -- as with farmed vegetables.


Dr. Gregor, eat your heart out!




-- Saul

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With reference to Michael's hint to criollio cacao, that's the variety apparently Pink sun and the other Amazon provider, Seven Hills, are marketing locally in Italy. I tasted both, their smell and taste is delicate and not very pungent, a sign of probably not very high total polyphenols content. This supports MRs contention. Taste often is a good qualitative judge in lieu of lab analyses (which I didn't receive). I recently switched back to another unprocessed cacao, El Ceibo from Bolivia, and that's distinctly stronger, more pungent and astringent: more TP→ more (-)epicatechins, the protective compound we're after.


The rule seems apparently to stand for EVOO, cacao, wine and many if not all foods: the stronger, astringent and pungent the taste, the higher the concentration of phenolic compounds. Of course we should also differentiate in which polyphenols we wish, for example polymeric tannins in wines are sometimes added and may not be so desirable in too high a concentration.


I doubt the taste of a common mortal may be able to do that though.

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Thanks Michael for the extensive report.


@Mccoy   I wrote elsewhere:  Looking at the 2014 ConsumerLab report that got a lot of attention, I notice that  the brands with the higher flavanol levels also tend to be the one's with the higher cadmium levels. (Ecuadorian cacao is noted elsewhere for high flavanol content but also for high cadmium.)

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Ah, OK, Sibiriak, I'm going to dissect the data later but right now I'm seeing that the lower cadmium contents belong to the chocolate bars, which are often only in part cacao, for example Lindt excellence is over 50% cacao butter. That's only one factor, although significant, another is the Threshold detection level of 0.3 mcg/g, I'm going to take my time since now I'm heading to the beach, daily dose of Cholecalciferol, and maybe iodine !!!!

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Sibiriak, any hypotheses which may be useful to refine our deeply ingrained orthorexic habits deserve to be examined!

I've just looked up the 3 top providers of flavanols in the list, but two of'em, reservage cocawell and cocoavia are flavanol supplements, so they are out of the issue, the 3rd is cocoa nibs so not the cacao powder which we are dealing with.  The most promising items must be crossed out if we want to stick to the powder (which I do).



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Among the powders higher in flavanols, Nestle's toll house cacao seems to be the best compromise at 0.5 ppms, also with not too much lead. Also, it seems to be totally defatted. The downside is that it is not organic. Unfortunately, it doesn't sell in my country.



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Our optimization strategy may also be based on the upper bound level of the cacao powders surveyed: 1.5 micrograms/g. Since the EPA reference intake threshold is 1 microgram/kg/day, we may assume we're reasonably safe eating a maximum quantity of our weight in kg/1.5. To me that's 65/1.5= 43 grams cacao powder, about 8 tablespoons, which is pretty copious. The drawback of this strategy is that the sample has small numerosity (n=6).

I'm about to study the European legislation, but I couldn't find so far the reference threshold in foods posted by MR (0.6 ppms content)

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1 hour ago, mccoy said:

Our optimization strategy may also be based on the upper bound level of the cacao powders surveyed: 1.5 micrograms/g. Since the EPA reference intake threshold is 1 microgram/kg/day, we may assume we're reasonably safe eating a maximum quantity of our weight in kg/1.5. To me that's 65/1.5= 43 grams cacao powder, about 8 tablespoons

... if there is zero cadmium in the rest of your diet, which is certainly not the case. Per this report, eg, the median intake of Cd in France is already 0.3 μg/kg/d for adults. And you probably get more Cd than average. Per the ASTDR, "age-weighted mean cadmium intakes of 0.35 μg/kg/day for males and 0.30 μg/kg/day for females were calculated for U.S. nonsmokers. In general, vegetables, particularly leafy vegetables such as lettuce (0.051 mg/kg) and spinach (0.124 mg/kg), have the highest concentrations of cadmium; the concentrations of cadmium in all vegetables ranged from 0.001 to 0.124 mg/kg (FDA 2010; Morrow 2001). Peanuts, soybeans, and sunflower seeds have naturally high levels of cadmium (Morrow 2001); the mean concentration of cadmium in legumes and nuts ranged from 0.001 to 0.054 mg/kg (FDA 2010). People who regularly consume shellfish and organ meats (liver and kidney) have an increased risk of cadmium exposure, as these organisms tend to accumulate cadmium (Elinder 1985a). "

1 hour ago, mccoy said:

I'm about to study the European legislation, but I couldn't find so far the reference threshold in foods posted by MR (0.6 ppms content)

It's a regulatory decision, not in the legislation, if you meant that literally. In the link I gave, they link the regulation. See 3.2.7, "Specific cocoa and chocolate products".

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Excellent points Michael, with the Cd quantities you cited I am probably above the EPA threshold and definitely maybe multiple times above the astr threshold, heck, I'm not even trying to estimate the amounts now. And cacao does not govern, whereas leafy greens do as you guessed correctly. I'll eat 300 grams of spinach like nothing and I'll already be at the EPA threshold. 

 Now maybe the issue might be organic versus inorganic cadmium, similarly to arsenic. 

And now lab analyses are in order, what is best, hair analyses?? A chance to check all others common heavy metals. 

Last, thanks for the new link, the EU regulations will start being enforced next year and we'll see when the member states will pick them up

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Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses

Br J Nutr. 2014 Sep 14; 112(5): 794–811.
PMCID: PMC4141693 PMID: 24968103

Cadmium and pesticide residues

Cd is a highly toxic metal and one of the only three toxic metal contaminants (the other two being Pb and Hg) for which the European Commission has set maximum residue levels (MRL) in foods( 53 ). Cd accumulates in the human body (especially in the liver and kidneys) and therefore dietary Cd intake levels should be kept as low as possible( 53 ). The on average 48 % lower Cd concentrations found in organic crops/crop-based foods in the meta-analyses carried out in the present study are therefore desirable, although the exact health benefits associated with reducing Cd intake levels via a switch to organic food consumption are difficult to estimate. Similar to the results of the present study, a recent literature review by Smith-Spangler et al. ( 21 ) has also reported that of the seventy-seven comparative data sets (extracted from fifteen publications), twenty-one indicated significantly lower and only one significantly higher Cd concentrations in organic foods. Differences in Cd contamination levels between organic and conventional winter wheat have recently been shown to be mainly linked to differences in fertilisation regimens (especially the high mineral P inputs used in conventional farming systems), although contrasting rotation designs also contributed to differences in Cd concentrations between organic and conventional wheat( 7 ). A range of other soil (e.g. pH) and agronomic (e.g. liming) factors are known to affect Cd concentrations in crops( 54 ), and these may explain the variability in results between individual comparative studies, crop species and crop types (see Fig. 4 and online supplementary Figs. S4 and S22).

Dietary Strategies for the Treatment of Cadmium and Lead Toxicity

Qixiao Zhai, et al.
Nutrients. 2015 Jan; 7(1): 552–571.
PMCID: PMC4303853 PMID: 25594439




Cadmium (Cd) and lead (Pb) are toxic heavy metals that cause adverse health effects in humans and animals. Chelation therapy, the conventional treatment for heavy metal toxicity, is reported to have a number of safety and efficacy issues. Recent studies have shown that dietary supplements play important roles in protecting against Cd and Pb toxicity. This paper reviews the evidence for protective effects of essential metals, vitamins, edible plants, phytochemicals, probiotics and other dietary supplements against Cd and Pb toxicity and describes the proposed possible mechanisms. Based on these findings, dietary strategies are recommended for people at risk of Cd and Pb exposure. The application of these strategies is advantageous for both the prevention and alleviation of Cd and Pb toxicity, as such supplements can be added easily and affordably to the daily diet and are expected to have very few side effects compared to the chelation therapy.

Cadmium accumulation in leaves of leafy vegetables.

Baldantoni D1, Morra L2, Zaccardelli M3, Alfani A4.

Ecotoxicol Environ Saf. 2016 Jan;123:89-94. doi: 10.1016/j.ecoenv.2015.05.019. Epub 2015 May 23.



Leafy vegetables have a relatively high potential for Cd uptake and translocation, and are thus considered Cd accumulators. For this reason, leaves and roots of lettuce (Lactuca sativa L.) and endive (Cichorium endivia L.) plants, grown on different agricultural soils in Campania region (southern Italy), subjected to different fertilisation treatments (unfertilisation, compost amendment and mineral fertilisation), were analysed for Cd concentrations. Moreover, to clarify if the highest concentrations found are linked to older and inedible or to younger and edible leaves, external and internal endive leaves were separately analysed.

All the leafy vegetables analysed showed on average 2-fold higher Cd concentrations in leaves than in roots. Leaf Cd concentrations in both lettuce and endive plants significantly differed among fertilisation treatments, with values highest in the plants grown on mineral fertilised soils. Apart from the soil fertilisation treatments, however, Cd leaf concentrations were often higher (up to 4-fold) than the threshold deduced by the EU 420/2011 Regulation, although the plants grew on unpolluted soils. Anyway, external leaves of endive plants showed significantly higher concentrations than internal leaves (in some cases the values were 3-fold higher), partly reassuring on the consumption of the younger leaves.

Moreover, this study points out two major drawbacks in the Italian and European regulatory frameworks: (1) metal concentration (as total and/or available fraction) limits in agricultural soils are lacking; (2) metal concentration thresholds (currently existing only for Cd and Pb in crops) reported in the EU 420/2011 Regulation, expressed on the fresh weight basis rather than on the dry weight basis, appear not suitable.

Arsenic, Cadmium, Lead, and Mercury in Sweat: A Systematic Review



Arsenic, cadmium, lead, and mercury exposures are ubiquitous. These toxic elements have no physiological benefits, engendering interest in minimizing body burden. The physiological process of sweating has long been regarded as “cleansing” and of low risk. Reports of toxicant levels in sweat were sought in Medline, Embase, Toxline, Biosis, and AMED as well as reference lists and grey literature, from inception to March 22, 2011. Of 122 records identified, 24 were included in evidence synthesis. Populations, and sweat collection methods and concentrations varied widely. In individuals with higher exposure or body burden, sweat generally exceeded plasma or urine concentrations, and dermal could match or surpass urinary daily excretion. Arsenic dermal excretion was severalfold higher in arsenic-exposed individuals than in unexposed controls. Cadmium was more concentrated in sweat than in blood plasma. Sweat lead was associated with high-molecular-weight molecules, and in an interventional study, levels were higher with endurance compared with intensive exercise. Mercury levels normalized with repeated saunas in a case report. Sweating deserves consideration for toxic element detoxification. Research including appropriately sized trials is needed to establish safe, effective therapeutic protocols.

* * * * * *

Excretion of Toxic Elements in Sweat

Along with essential minerals, sweat is an acknowledged excretory route for toxic metals. For instance, it is recommended to sample hair close to the scalp because content of toxic elements may be elevated along the shaft, from either environmental contamination or excreted toxins in sweat and sebum [32, 42]. The minerals generally arise from blood serum [28], with contribution from dermally absorbed occupational exposures, which might not be reflected in blood or urine [35, 37]. Sweating was induced by sauna, exercise, or pilocarpine iontophoresis to measure the concentration of the heavy metals in the sweat, while sauna and exercise were used for therapy. Study participants included workers with occupational exposures and individuals with no occupational exposures who were well or experiencing chronic ill health, and in two studies participants were intentionally dosed with lead [34, 37]. Studies that have examined the presence of toxic metals in sweat are summarized in Tables Tables1,1, ,2,2, ,3,3, and and4,4, for arsenic, cadmium, lead, and mercury, respectively.






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Thanks Sibiriak, I found particularly useful the article by Zhiao et al. on dietary strategies. We already discussed about zinc and its competition to be bound with cadmium specifically. The article suggests that Calcium and Iron also compete with Cd and Pb, giving us one more important reason to abound with such metals.

An interesting point would be to estimate the quantity of Zn supplements to take with this specific purpose (for example, if it is advisable to take more than the advised dose of 25 mg/d to enhance the competition with Cd and Pb).

Another very important point: since Zn has affinities with Cd and Pb, it is imperative that the supplement we use is not contaminated (necessity of a certification). 

Also, the phytochemicals which counteract the effects of Cd and Pb are the ones which we usually ingest in abundance. In particular, catechins in cacao seem to be an inherent natural antidote to teh abundance of zinc.

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Mccoy: An interesting point would be to estimate the quantity of Zn supplements to take with this specific purpose (for example, if it is advisable to take more than the advised dose of 25 mg/d to enhance the competition with Cd and Pb)

That's an interesting question, but  I would cautious about taking more Zinc than otherwise necessary for general health.    There is some evidence of potential harm from excess zinc supplementation. 

Zinc Supplement Use and Risk of Prostate Cancer

JNCI: Journal of the National Cancer Institute, Volume 95, Issue 13, 2 July 2003




The high concentration of zinc in the prostate suggests that zinc may play a role in prostate health. We examined the association between supplemental zinc intake and prostate cancer risk among 46 974 U.S. men participating in the Health Professionals Follow-Up Study. During 14 years of follow-up from 1986 through 2000, 2901 new cases of prostate cancer were ascertained, of which 434 cases were diagnosed as advanced cancer. Supplemental zinc intake at doses of up to 100 mg/day was not associated with prostate cancer risk. However, compared with nonusers, men who consumed more than 100 mg/day of supplemental zinc had a relative risk of advanced prostate cancer of 2.29 (95% confidence interval = 1.06 to 4.95; Ptrend = .003), and men who took supplemental zinc for 10 or more years had a relative risk of 2.37 (95% confidence interval = 1.42 to 3.95; Ptrend<.001). Although we cannot rule out residual confounding by supplemental calcium intake or some unmeasured correlate of zinc supplement use, our findings, that chronic zinc oversupply may play a role in prostate carcinogenesis, warrant further investigation.



These cautionary findings were confused by a 2011 Swedish study that assessed dietary zinc levels in 525 men when they were first diagnosed with prostate cancer. Those with high dietary zinc intake had a 36% lower risk of dying from prostate cancer than those with low intake. These results strongly suggested that "high dietary intake of zinc is associated with lower prostate cancer-specific mortality after diagnosis, particularly in men with localized disease.”6 Keep in mind this study compared zinc intake from food, not from supplements.

A 2014 cell study explained that long-term zinc exposure helps prostate cancer cells become resistant to treatment by a range of chemotherapy drugs, including cisplatin. Zinc led to chemo-resistance in a range of different tumor cell lines via KRAS NF-κB.7 Then in early 2017 these mechanisms were more clearly defined by a paper by Kratochvilova et al, who showed that long-term treatment with zinc “significantly enhanced cisplatin resistance, invasiveness, cellular antioxidant capacity, synthesis of glutathione" and expression of treatment-resistant genes in prostate cancer cells.8 This is not what we would want to happen


As always, the issue is complex,  and I really need to review the evidence regarding optimal  zinc supplement intake.

Michael Rae has written that the   absolute level  of zinc intake (dietary  and supplemental)  "should probably not exceed 50 milligrams",  and he characterized Dean P.'s  previous intake of 50 mg/d of supplemental zinc as "very high". So if you went up from 25 mg/d to,  say, 40 mg/d,  the question is, would that have any significant  impact on long term cadmium etc. levels and health outcomes?    I doubt you could do much more than speculate.

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  • 1 month later...

Note that CL has updated their flavanols/chocolate/cadmium report (probably paywalled; I paid). The top says, "last update 9/12/18".

Cacao powders generally seem to have more cadmium than nibs. By lucky chance the nibs that they tested that had the best flavanol to cadmium ratio was what my family has been using anyway, Navitas Naturals (so maybe this got better since the 2014 report) and for the double-win my favorite dark chocolate, Endangered Species 88%, did the best of bars (excluding a 100% bar) and had an even better flavanol to cadmium ratio than the Navitas Naturals nibs, though with the disadvantage of some sugar.

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