Commercially Available Teas "Not Suitable For Human Consumption": Potentially Hazardous Amounts of Lead, Aluminum, Arsenic & Co in Every Cup

Would all commercially available teas have to be labeled like this?

I am usually not a fan of articles with titles like this one (see above) - they have what you call in Germany "Bildzeitungsniveau" (the German tabloid with news like "World about to disappear in a black hole, when CERN starts operating). It is however hard to resist the urge to use a headline like the one above, if the it fits the results of peer-reviewed scientific paper so well, as it is the case with the relatively recent paper from the University of Alberta and the Luleâ University of Technology in Sweden this SuppVersity article is (almost) all about.

The corresponding experiment, the results of which were published in the peer-reviewed open-access Journal of Toxicology in October 2013, already, addresses the increasing concern about contamination of foodstuffs and natural health products. With the emphasis being on foodstuff and health, it's only logical that tea, or more precisely all currently available off-the-shelf varieties of black, green, white, and oolong teas sold in tea bags were used for analysis in the said study.

So what did the researchers do?

Schwalfenberg, Genius (no joke, the 2n author is a real 'Genius by name') and Rodushkin conducted a three-step analysis in the course of which they analyzed the content of previously identified tea contaminants like aluminum, fluoride, mercury, lead, cadmium and arsenic (Fujimaki. 2004; Lung. 2008; Wang. 2008; Alvarez-Ayuso. 2011; Tan. 2012) in commercial tea preparations.

Table 1: There are not just bad, but also healthy minerals in tea!

Before we get to the "bad stuff", though, let's start with the positive findings of their investigation. The data in Table 1 is after all evidence enough that there are also "healthy" minerals in tea - the amount is not high enough to cover your RDA, but this does not mean that it could not be at least partly related to the undeniable health benefits researchers all around the world report for people who consume uncontaminated tea on a regular base. As a loyal SuppVersity readers you know most, if not all of them from previous articles on tea. The reason I still believe it's worth enumerating them again is that I don't want you to give up on your beloved (?) tea too easily - I mean, Coke is not an alternative and for coffee fungi and other stuff could make a similarly unhealthy "supplement" to your breakfast beverage:

• Cardiovascular benefits - When we are talking about health in general and heart health in particular, most people will think of green tea. That's pretty unfortunate, because there is ample research for all varieties of teas that they can lower blood lipids, provide "clean" and thus heart healthy energy, and exert antithrombotic and anti-hypertensive effects.
• Anticancer effects - Despite the fact that the anti-cancer effects have mostly observed in in-vitro studies, there is plenty of epidemiological evidence that tea drinkers have a lower cancer risk, than the average coke guzzler (not necessarily breast cancer, though ➫ SuppVersity Facebook News).
• Metabolic syndrome - While more recent studies clearly suggest that the active weight loss effects of tea, in general, and green tea, in particular, have been totally overblown, there is still a host of controlled trials, where adding tea (not necessarily green tea) improved the effects of a energy restricted diet. Compared to the rodent trials which are still fueling the myth of the potent thermogenic effects of (green) tea, the real world results in human beings are however downright disappointing.

• 

  A green tea marinade will keep your meats fresh | learn more

  Anti-infective properties - Only few people (SuppVersity readers included - of course) know that green tea can be used as a mouthwash and is currently researched as an anti-bacterial food additive by researchers all around the world. According to a paper by Steinmann et al. (2013), the anti-infective effects are mediated by the antiviral, antibacterial, and antifungal properties of Epigallocatechin gallate (EGCG). The same EGCG about which you've read only recently on the SuppVersity that it is not exactly as useful as a fat loss adjuvant, as the hype would have you believe.
• Other beneficial effects - Under "Miscellaneous Effects", Schwalfenberg et al. also list the nephropotective effects of green tea, which could come very handy if you guzzle mercury contaminated green tea, everyday (unfortunately, mercury is your least problem with tea), the anti-depressive researchers have observed in people consuming 4+ cups of tea per day and the hitherto unconfirmed hypothesis that tea drinkers are (better) protected against Alzheimer’s and neurological decline.

In view of these benefits it's only logical that the Canadian + Swedish research team chose to repeat  the dichotomous health effects of drinking tea in the title of their paper "The Benefits and Risks of Consuming Brewed Tea" (my emphasis in Schwalfenberg. 2013)

Organic is not better than regular tea

To obtain a dataset that would be as comprehensive, accurate and practically relevant as possible the authors bought 30 different organic and non-organic white, green, oolong, and black teas from the the shelves of Canadian supermarkets and analyzed (a) the "raw" tea leaves (LEAF), (b) tea that had been steeped for 3-4 minutes (3MIN), (c) tea that had been steeped for 15–17 minutes (15MIN).

Know your teas: As a SuppVersity reader you will probably know that all teas come from the same plant. It's the processing that determines if we call it "white", "green", or whatever else:

• White tea: young leaves or new growth buds, withered, uncured, baked dry 
• Green tea: steamed or dry cooking in hot pans to prevent oxidation; dried tea leaves may be separate leaves or rolled into pellets (gunpowder tea)
• Oolong tea: withering of leaves under sun and warm winds with further oxidation standard between green and black teas
• Black tea: leaves are completely oxidized, withered

Due to the processing of the leaves tea from the same camellia sinensis plant can contain different amounts of contaminants depending on whether you buy it as white, green, oolong or black tea, or shredded green tea supplement.

Still, the main determinant is and remains the soil it was grown on (see Table 4)?

All tea samples underwent the same standardized procedures before they were analyzed in their raw form (cut / shredded leaves) or as an infusion that had been prepared with only one tea bag (containing 2-3g of tea) in 250 mL of distilled water in fine bone china cups.

As you will already have expected, the scientists did not just detect the previously mentioned "good minerals" (exact values see Table 1), and a host of other beneficial trace elements, i.e.

• boron 19–115µg/L, cobalt 0.4–3.56µg/L, 
• copper 26–106µg/L, chromium 0.2–14.6µg/L, 
• iron 19–62.5µg/L, manganese 534–6351µg/L, 
• molybdenum 0.03–0.131µg/L, 
• selenium <0.1–0.34µg/L, 
• vanadium <0.01–0.151µg/L, and zinc 44.6–187µg/L,

in their samples. Schwalfenberg et al. found highly significant and, more importantly, physiologically relevant amounts of toxic elements, as well:

Table 2: Established toxicant limits in supplements (µg/day).

If you look at the value in Table 3 and compare them to the limits in Table 2, there is one thing you should keep in mind: These limits have been set by average exposure, not based on toxicity tests - that sounds very comforting, right?

"Public health warnings or industry regulation indicated" -- It sounds pretty fearmongering and I would not have used it as a subheading right beneath the introduction, if the statement "Public health warnings or industry regulation might be indicated to protect consumer safety." (Schwalfenberg. 2013) was no literal citation from the conclusion of the paper I have here right in front of me.

Table 3: Levels of mercury (Hg), lead (Pb), aluminum (Al), arsenic (As) and cadmium (Cd) in tea infusions after 3-4 or 15-17 min of brewing; all values in µg/L (Schwalfenberg. 2013)

A brief glimpse at the data in Table 3 does moreover confirm there are plenty of toxins in the average Canadian super market tea, but it does not tell you how problematic the contamination actually is. To understand that you'd have to cimpare those values to the established toxicant limits Table 2, which do - and this is and will always be ridiculous -  obviously depend on where you live *sarcastic laughter*... but enough of the unproductive sarcasm, let's see what we've got:

"All teas contained significant amounts of aluminum. Tea  leaves contained from 568 to 3287 ng/g of tea. All brewed teas steeped for 3 or 15 minutes contained detectable levels of aluminum. The range was 1131µgm/L to 8324µgm/L steeping for 3 minute and 1413µgm/L to 11449µgm/L steeping for 15 minutes. Only 2 teas had levels above acceptable limits at 3 minutes of brewing but 6 of the teas had levels greater than the upper acceptable daily limit of 7000µgm/L. Clearly letting tea steep for longer than 3 minutes is not advisable. Two of the organic green teas had levels above 10,000µgm/L brewed for 15 minutes."

In view of the fact that tea is by far not the only aluminum source you are expose to, the high levels of this toxic metal that easily accumulates in the body should be reason enough not to brew your tea - especially not organic tea - for more than 3 minutes.

Organic tea is a worse offender than regular

If you take a look at the amount of lead in the various tea samples it becomes even more obvious that "organic" tea is not necessarily better for your organs, as well. This is particularly true for the best-sellers green and black tea, both of which contain significantly more lead in the "organic" vs. "regular" variety.

Table 4: Toxicant levels according to origin; Pb: lead, Cd: cadmium, Al: aluminum, As: arsenic (Schwalfenberg. 2013)

Probably the main factor that influences the toxicant levels of teas is the place of origin, thoug. As you can see in the overview in Table 4, the highest amount of arsenic, was detected in Chinese oolong teas (organic or regular). The total arsenic levels in all teas, which ranged from 0.06µgm to 1.12µgm/L for tea that had been steeped for 3 minutes to 0.08 to 1.27µgm/L for tea that had been steeped for 15 minutes was highest in white tea - obviously also from China. And last but not least, ...

"...[a]ll tea leaves had detectable levels of cadmium. 21 teas had detectable levels after 15 minutes brewing while only 18  teas had detectable levels after 3 minutes brewing suggesting that there is further leaching of this toxicant into the water over time. [As the overview in Table 4 already suggests] the highest level was 0.067µgm/L found in standard oolong tea from China." (Schwalfenberg. 2013)

Not listed in the tables are the levels of tin, barium, antimony and thallium, which were detected in all tea samples, but at levels of which the authors state that they don't have to be "considered to be of concern" (Schwalfenberg. 2013).

Should you stop drinking tea? You know that I don't like to tell people what to do. Unless, obviously I am 100% sure that I am convinced that there is a serious health risk involved.

In the case of green, black or white tea, the evidence that this is the case is yet insufficient. Personally, I will still make sure to check the geographic origin of the tea leaves (not where it was processed and packaged!) and avoid all products with the bad 5-letter word C-H-I-N-A on the label.

Bottom line: "Not of concern" is not exactly what I would say about the overall results of the study at hand. I mean, in the end, the high levels of toxicants in some of the commercially available tea preparations - specifically those from China - could actually explain why the real-world results with commercially available teas and tea supplements often fall short of the rodent studies, which are often conducted with highly purified green tea products from companies like Sigma Aldrich.

Ah, ... one last thing to keep in mind is that 18 out of 30 tested commercial tea preparations contained mercury in amounts that were as high as 20 ng/g, but did not make it from the leave to the tea. With your digestive tract being a much more efficient nutrient and (unfortunately) toxicant extractor than hot water, tea supplements could pose an even greater risk of heavy metal exposure than tea.

References:

• Álvarez-Ayuso, E., Giménez, A., & Ballesteros, J. C. (2011). Fluoride accumulation by plants grown in acid soils amended with flue gas desulphurisation gypsum. Journal of hazardous materials, 192(3), 1659-1666.
• Hayacibara, M. F., Queiroz, C. S., Tabchoury, C. P. M., & Cury, J. A. (2004). Fluoride and aluminum in teas and tea-based beverages. Revista de Saúde Pública, 38(1), 100-105.
• Lung, S. C. C., Cheng, H. W., & Fu, C. B. (2007). Potential exposure and risk of fluoride intakes from tea drinks produced in Taiwan. Journal of Exposure Science and Environmental Epidemiology, 18(2), 158-166.
• Steinmann, J., Buer, J., Pietschmann, T., & Steinmann, E. (2013). Anti‐infective properties of epigallocatechin‐3‐gallate (EGCG), a component of green tea. British journal of pharmacology, 168(5), 1059-1073.
• Tan, Z., & Xiao, G. (2012). Leaching characteristics of fly ash from Chinese medical waste incineration. Waste Management & Research, 30(3), 285-294.
• Schwalfenberg, G., Genuis, S. J., & Rodushkin, I. (2013). The Benefits and Risks of Consuming Brewed Tea: Beware of Toxic Element Contamination. Journal of toxicology, 2013.
• Wang, X. P., Ma, Y. J., & Xu, Y. C. (2008). [Studies on contents of arsenic, selenium, mercury and bismuth in tea samples collected from different regions by atomic fluorescence spectrometry]. Guang pu xue yu guang pu fen xi= Guang pu, 28(7), 1653-1657.

Coffee Rules, Green Tea Sucks!? Study Links Green Tea to Insulin Resistance and Coffee to Insulin Sensitivity. Statist. Outlier, Long- vs. Short Term Effect or Heavy Metal Toxicity?

I can't tell if bathing in coffee is healthier than in tea, but my gut tells me that it is.

Coffee may rob your sleep (see "Sleepness Nights: Are Pre-Workouts and A Huge Cup of Coffee Messing With Your Sleep?" | more), but if you look at the currently available epidemiological data, the average coffee drinker is still a pretty healthy chap. Whether this is due or in spite of the stimulating effects of caffeine is not quite certain, but a closer look at its molecular composition reveals that the average cup of real coffee has at least as many potent antioxidants, as green tea. From a molecular perspective coffee is thus by no means inferior to the catechin-laden purported health-elixir green tea. With its glucose-6-phosphatase inhibitory (van Dam. 2006) and insulin sensitizing effects (Shearer. 2003) of its chlorogenic acid and quinide, coffee has, just like green tea, tons of animal data to support its potent anti-diabetic effect.

What's healthier tea or coffee?

If you asked one hundred people, what they'd choose, coffee or green tea, if personal preferences weren't an issue and their only criteria were "beneficial health effects", I am 100% convinced that the vast majority would go with green tea. That's actually quite natural, the media does after all hype every epidemiological study that supports the notion that green tea drinkers are the healthiest chaps on earth. Studies like the one researchers from the National Center for Global Health and Medicine in Tokyo are about to publish in the venerable scientific journal Metabolism, on the other hand, are rarely present on any of the major science news outlets.

Did you know that... An inverse association between coffee consumption and HOMA-IR has been observed in the US, Sweden, the Netherlands and multi-ethnic Asian populations, the study at hand is yet the first to confirm the existence of health benefits in a Japanese population.

This is where the SuppVersity comes into play. Your place to learn that Pham et al. observed an "unexpected", statistically significant association between green tea consumption and elevated HOMA-IR levels - in other words: The regular consumption of green tea was associated with an impaired glucose metabolism / lower baseline insulin sensitivity.

Figure 1: Relative differences to coffee / green tea "no consumers" in subjects who drink different amounts of coffee and green tea every day; p-values are given in boxes only for significant changes (Pham. 2013).

These results were obtained using data from cross-sectional epidemiological surveys that had been conducted among employees of three workplaces, two municipal offices in Kyushu and one
manufacturing company, in Kanto in 2009 and 2012. Pregnant women and subjects reporting a history of stroke or cardiovascular disease (n = 25), cancer (n = 27), diabetes (n = 52) and chronic kidney disease (n = 9), as well as those who were current usersof anti-diabetic drugs (n = 1) or under medical care for hepatitis (n = 4) were excluded to minimize the influence of confounding factors and be able to make a statement about the associations between coffee and tea consumption and glucose management in the average healthy Japanese worker.

Table 1: Characteristics of the study subjects by coffee consumption; the yellow mark indicates stat. sign. inter-group differences (Pham. 2013)

"Information about dietary intake during the preceding month was obtained using a validated brief self-administered diet history questionnaire (BDHQ). Dietary intakes for 58 food and beverage items including coffee and green tea, energy, and selected nutrients were estimated using an ad hoc computer algorithm for the BDHQ, with reference to the standard tables of food composition in Japan.

The response options for coffee or green tea consumption were never, < 1cup/week (wk), 1 cup/wk, 2-3 cups/wk, 4-6 cups/wk, 1 cup/day (d), 2-3 cups/d, or ≥4 cups/d." (Pham. 2013)

It is probably not surprising that the comparatively detailed dietary analysis revealed significant correlations between the consumptions of coffee and green tea (Spearman’s r= 0.83 and 0.77 for coffee in men and women, respectively; Spearman’s r= 0.68 and 0.64 for green tea in men and women, respectively) - with a high enough subject base you can however subtract the individual influence of the two out.

Is there any reason green tea could compromise our insulin sensitivity

I have to admit that there is little direct experimental evidence that would explain the observations th researchers made, but if you remind yourselves of the first serving of the "Supplements to Improve and Restore Insulin Sensitivity" Series (overview), you will remember that the anti-diabetes effects of green tea / green tea supplements are - if they occur at all - indirect ones.

Don't forget that caps and pills are not worth a penny without you committing to the all the lifestyle changes I outlined in episode one of the "Supplements to Improve and Restore Insulin Sensitivity" series.

Unlike the bioactive substances in coffee, which have a direct beneficial effect on skeletal muscle glucose uptake, those of the often-hailed green tea catechins are primarily side effects of improvements in lipid metabolism and reduced chronic inflammation.

Assuming that the average study participant did not have significantly elevated blood lipids and wasn't chronically inflamed either, this would explain the absence of improvements in insulin sensitivity. What it doesn't explain, though, is the fact that the insulin sensitivity decreased - irrespective of the accumulating evidence which suggests that even diabetics don't benefit from green tea supplementation (latest example from Nov, 8  Wang. 2013)

Usually this is, when you take a look at the discussion in a scientific paper, read, digest and get an idea of what could be a reasonable explanation for unexpected phenomena like this. The conclusion of the paper at hand, does yet only summarize the existing scientific evidence that the vast majority of "previous studies have shown no association between habitual green tea consumption and fasting glucose" (Pham. 2013):

• a Japanese study among 1542 men reportedmarginally-significant higher odds ratios for IR with higher habitual consumption of green tea (T Otake April 2013, personal communication of the authors of the study at hand)
• Rebello et al. reported no association between green tea consumption and HOMA-IR among a multi-ethnic Asian population
• a meta-analysis including 6 clinical trials found no evidence to support an effect of green tea catechins on HOMA-IR

As Pham et al. points out conclusive evidence for or against the benefits of green tea consumption from long-term + large-scale trials is missing. Most clinical trials including those in in the previously cited  meta analyses had relatively short-term intervention (4-24 wks) and modest sample sizes (23-88 subjects). Without further research it is thus more or less impossible if genetic, lifestyle or other confounding variables or a hitherto overlooked negative long-term effect of green tea are responsible for the results. 

Table 2: Levels of toxic trace elements in tea infusion; data compiled by Tanmoy Karak, R.M. Bhagat (2010)

Aside from biological factors, the disappointing results could also be the consequence of the quality of the tea. In Japan, the upper tolerable levels for lead (Pb) are for example 4x higher, than in Europe (20mg/kg vs. 5mg/kg). With the ever-increasing Pb concentrations in tea leaves (Jin. 2005), lead and other toxic elements (see data in Table 2) could be turning the health elixir into an increasingly toxic cocktail.

"Coffee, Tea, Cacao, Caffeinated Sodas & Breast Cancer: 5+ Cups/Day?! Study & Meta-Analysis Show, It May Take More Coffee Than Previously Thought to Ward Off Breast Cancer" | more

Treat with caution: I strongly recommend not to overestimate the results of the study at hand - neither the negative ones about green tea, nor the positive ones about coffee. A BMI-stratified analysis did after all reveal that the inverse association (not causation) between coffee consumption and HOMA-IR was really significant only in the overweight/obese, but not in normal-weight, individuals.

In view of the absence of a reasonable explanation for the pro-diabetic effects of chronic green tea consumption (it may in fact be heavy metals; see Table 2), I would not suggest you switch from green tea to coffee, if you don't like it. If you are a coffee-boy or -girl, anyway, the study at hand confirms that reductions in diabetes risk are not a good reason to give up on your beloved brown brew ;-)

References:

• Jin CW, He YF, Zhang K, Zhou GD, Shi JL, Zheng SJ. Lead contamination in tea leaves and non-edaphic factors affecting it. Chemosphere. 2005 Nov;61(5):726-32.
• Wang X, Tian J, Jiang J, Li L, Ying X, Tian H, Nie M. Effects of green tea or green tea extract on insulin sensitivity and glycaemic control in populations at risk of type 2 diabetes mellitus: a systematic review and meta-analysis of randomised controlled trials. J Hum Nutr Diet. 2013 Nov 8.
• Karak T, Bhagat RM. Trace elements in tea leaves, made tea and tea infusion: A review. Food Research International. 2010; 43(9):2234–2252.

Lose(!) 33% Body Fat in 10 Days!? The Heavy Metal Obesity Link: Study Shows "Preventive Role" for Inorganic Cobalt in Obesity-Related Diseases.

Image 1: Cobalt - certainly not what you would expect to see at a health food store or pharmacy; with Kawakami et al.'s study this may change in the future (img Alchemist-hp)

"We are living in a toxic world!" - you have probably heard or read this sentence more than once and while I cannot deny that the environmental load of, among others, heavy metals appears to be increasing, I can however tell you that, according to a recent study from scientists from the Tukushima Bunri University in Japan, exposure to some of those heavy metals produces quite unexpected results in a rodent model of the metabolic syndrome and in lean controls. Instead of making them gain weight even more rapidly, the "toxic" (maybe we will have to reconsider that, just as we did in the case of chromium) heavy metal cobalt did not only reduce the weight of the white adipose tissue of the rodents, it increased leptin, adiponectin, and HDL-cholesterol, as well, and thusly "may have a preventive role in obesity-related diseases" (Kawakami. 2011)

This is certainly the 1001st time I am writing this, but I cannot emphasize often enough that the "high fat diet" researchers use in their studies has (in most cases) nothing to do with the Atkins or even a low-carb diet. Its main characteristic is that it is hypercaloric and high in fat and carbs. Please keep that in mind whenever you read about another study on the detrimental health effects of "high fat diets".

For 24days Kawakami et al. fed a group of seven-weeks-old male mice either a standard diet with 357.6kcal/100g or a hypercaloric (cf. red box above) high fat diet (HFD), where the latter induced obesity and dislepidemia within 2 weeks. After this initial phase, i.e. when the HFD mice were already obese and metabolically deranged, the scientists injected the animals with Sodium Arsenite (NaAsO2: 1.0 mg/kg bw), Mercuric Chloride (HgCl2: 1.0 mg/kg bw), Manganese Chloride (MnCl2: 5.0 mg/kg bw), Cobalt Chloride (CoCl2: 0, 1.3, 5.0, 7.5 mg/kg bw) or saline (control).

Figure 1: Modulatory effects of 10 days of heavy metal injection in mice on a high fat diet; values expressed as changes relative to animals on a normal diet (data calculated based on Kawakami. 2011)

Now, if you look at the data in figure 1, you will notice that the administration of Mercuric Chloride may have been most "effective" in ameliorating the HFD-induced increase in white adipose tissue (WAT) mass (HFD +70%; HgCl2 -14% vs. normal fed control), but those "fat burning" effects went hand in hand with profound elevations of the liver enzymes AST, ALT (in this case we can safely assume that these were not coming from the muscle tissue of the animals) and the blood urea nitrogen (BUN) levels, which indicate deteriorations of the kidney metabolism. Manganese and cobalt, on the other hand, had negligible or even beneficial effects (compared to HFD alone) on liver and kidney health and ameliorated the weight gain to +10% and +17%, respectively.

Figure 2: Adiponectin and leptin serum levels and mRNA expression in mice after 10 days on a high fat diet with simulatenous injection of mercury or cobalt; data expressed relative to normal fed control (calculated based on Kawakami. 2011)

What is particularly interesting about cobalt, though, is that it did not simply starve out the adipose tissue by poisoning it (like that was probably the case for mercury), but triggered exactly those metabolic adaptations scientists have been trying to provoke with drugs for years now: elevations in adiponectin and leptin (cf. figure 2), the two adipokines, researchers currently believe to be essential for successful weight loss / maintenance.

Figure 3: pAMPK/AMPK ratio after injection of different dosages of Cobalt chloride (calculated based on Kawakami. 2011)

In a follow up experiment, the scientists, also found that cobalt dose-dependently increases AMPK phosphorylation (for more on AMPK, I would like to refer you to the Intermittent Thoughts series) in white adipose tissue (WAT), muscle and liver of the animals (cf. figure 3). Of the three tested dosages, administration of 5mg/kg CoCl2 per day resulted in the most beneficial AMPK response, while with the maximal dose of 7.5mg/kg the negative / toxic effects appear to prevail (another of these bell-shaped dose-response curves, I guess).

Figure 4: Glucose tolerance test in mice on high fat diet with or without cobalt injections compared to mice on standard diet (control); values in mg/dl (data adapted from Kawakami. 2011)

Now, you are probably asking yourselves: "So what's the catch?". A brief look at figure 4 tells you that is ain't glucose intolerance, as the cobalt treated animals had the exact same response to the glucose tolerance test, as the mice on the normal diet - in other words: cobalt completely reversed the HFD induced glucose intolerance, and it did so not only without negative effects on blood lipids, but in the presence of a profound elevation of HDL levels and a reduction in LDL levels (cf. figure 5).

Figure 5: Relative (to normal fed control) changes in blood lipid in mice on a high fat diet with or without heavy metal injections (calculated based on Kawakami. 2011)

And as if that was not enough, the cobalt injections also eradicated the iincreases in free fatty acids and ameliorated the increase in triglycerides.

From the lab to the bedside?

Last but not least, and I hardly dare showing you this graph, because I would expect that some of you will already be googling a source of injectable cobalt (which would be plain out stupid, before any reliable safety data and confirmation of these results in controlled human trials are available), cobalt had almost identical effects when it was injected to the mice on the normal diet.

Figure 6: Relative changes in body composition and liver and kidney parameters due to heavy metal injection in non-obese mice on a standard diet (calculated based on Kawakami. 2011)

As figure 6 goes to show the mice lost 33% of their white adipose tissue and liver, as well as kidney function did not take a beating (HDL stayed the same, LDL decreased by -1%). Whether we will see a obesity or even just a weight-loss drug based on cobalt in the near future, does yet still seem questionable. In view of the fact that the number of "bad things" (cobalt is in fact an essential nutrient as it is the active center of vitamin B12 = cobal-amin) that have unexpectedly positive health effects is increasing day by day, we do yet obviously have to ask ourselves, whether there may be some major flaws in our current understanding of how our body works and how it deals and is effected by "toxins", oxidants and co.

NAC + Zinc + Selen = Silver Bullett Against Mercury Poisoning

Mercury certainly is among the most dangerous and, at the same time, most ubiquitous heavy metals, we are exposed to. In a recent article (thanks to Dominique for raising my awareness of its publication) strength coach Charles Poliquin references a 2010 study from Michigan State (Wirth. 2010) :

Looking at several well-designed studies, they determined that even low exposures from cadmium, lead and mercury had an impact on semen quality and reproductive hormone levels in men.

As far as solutions to this problem are concerned, Polliquin refers somewhat dubiously to "a specific herbal combination" of "andrographis paniculata, zinc citrate, humulus lupulus, and curcuma longa" without providing scientific evidence for why he thinks this specific formula would work (guess what, Charles sells it ;-). Chances would have it, though, that Joshi et al., in a very recent study (Joshi. 2011, still ahead of print) report the beneficial effects of another, from my perspective, probably even more potent combination of nutrients/antioxidants in experimentally induced mercury poisoning:

Exposure to DMM [dimethylmercury] caused significant alterations in cytochrome P450 (CYP) activity, microsomal lipid peroxidation, and proteins [in rats]. Activities of transaminases (aspartate aminotransferase/alanine aminotransferase), alkaline phosphatase, and lactate dehydrogenase in serum, as well as activities of CYP enzymes aniline hydroxylase (AH), amidopyrine-N-demethylase (AND) in liver microsomes and activities of acid phosphatase, alkaline phosphatase, glucose-6-phophatase, and succinic dehydrogenase in the liver and kidney, were significantly altered after DMM administration. DMM exposure also induced severe hepato-renal alterations at the histopathological level. NAC, along with Zn and Se, dramatically reversed the alterations in all of the variables more toward control.

Actually these results do not come as a surprise, as all three of these nutrients/antioxidants are well-known for their beneficial effects on (liver) enzyme activity and thus heavy metal clearance. Those of you, who read Tim Ferris' book The 4 Hour Body may also remember that his Brazil nut consumption (he ate them for their high selenium content, 1 ounce contains 544µg, i.e. 780% DV) along with other nutritional changes tripled his testosterone levels from low normal levels to the upper quartile of the range. In that, it is of secondary importance whether this was a mercury related effect, or not, since an increase in the detoxification abilities of the liver, as it was achieved in the study by twice a week supplementation with NAC (360mg/kg; human equivalent dose [HED] ~ 52mg/kg)  + Zn (130mg(kg; HED ~ 26mg/kg) + Se 0.5mg/kg; HED ~0.08mg/kg), will benefit the hormonal millieu via multiple pathways (increased estrogen clearance being one of them).

A word of caution: I advice against using the dosing scheme applied in the study, i.e. twice a week mega-dosing of supplements. Spread across a whole week, the human equivalent doses (for an 80kg human being) would equal roughly 600mg NAC, 300mg Zinc and 1mg* Selenium per day, which - apart from the exorbitant amount of zinc (I would not take more than 100-150mg/day even for short term interventions) - constitutes a quite reasonable nutrient stack for shorter detox protocols (4-6 weeks) for mercury, cadmium (cf. eg. Said. 2010) and other heavy metals with an increase in testosterone being one of the possible positive "side effects".

*Note on selenium toxicity: Rumors have it that selenium is toxic even at doses of >400µg. Most of these reports yet turned out to be based on anecdotal evidence from people who poisoned themselves with supplements that contained up to 200x the labeled dose (e.g. >40mg! selenium in MacFarquhar. 2010). It is thus very unfortunate that current data on the ‘Lowest Adverse Effect Level’ (LOAEL) is lacking. A 1989 study by Yang et al. give1.5mg/day as a threshold beyond which longterm supplementation may produce adverse side effects. And though this is below the 1g derived from the results of the rat study, I recommend to better err on the side of caution and to stick to max. 200-400µg supplemental selenium + a handfull of Brazil nuts from time to time as part of a safe antioxidant supplement stack.