Showing posts with label detoxification. Show all posts
Showing posts with label detoxification. Show all posts

Wednesday, March 23, 2011

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.

Sunday, December 5, 2010

Absurd: Will Supplemental Zinc Gluconate Deplete Your Zinc Levels?

Normally, I restrict myself to very recent studies, but the results of this 2007 (Tompkins. 2007) study on the bioavailability of zinc-enriched yeast and zinc gluconate in healthy volunteers that recently resurfaced on the Mind&Muscle boards, is too counter-intuitive and, if not scientifically flawed, important not to make it into the news.

In the study, which used a randomized, two-way crossover design, the volunteers were randomly assigned in groups of three to consume a single dose of either 20 mg of total Zn in the form of Zn gluconate or Zn yeast with 150 ml of water, after that urine, blood, and fecal samples were collected and analyzed over a 48-h period. The results were surprising, while "Zinc gluconate gave higher Zn concentrations in the blood in the first 6 h" it did not only show greater loss in the feces, but ...
the net Zn balance after 48 h for Zn yeast was 9.46 but for Zn gluconate it was -2.00, indicating that Zn gluconate supplementation contributed to a net loss of Zn.
As far as the reasons for this observations are concerned, the scientists speculate:
Presumably, this “extra” Zn lost was released from the body’s store of Zn metallothionein; however, we do not have any evidence of the source of the Zn material. This may suggest that the Zn salts stimulated a Zn detoxification pathway.
If this were true and the results are not biased by the background of the Institut Rosell, which is obviously financed by Lallemand Inc. who produce (pro-)biotic products (i.e. yeast based products), you might want to reconsider your own supplementation practices. The high doses of Zn Salts commonly used by bodybuilders and fitness enthusiasts (many suggest >50mg Zinc per day) may in fact lead your body to believe he becomes intoxicated with zinc. It is then a very natural reaction to excrete zinc and as the data from this study shows, this "excess" zinc (i.e. more zinc than you supplied) must - at least in parts - stem from zinc stores somewhere in your body.