Drinking heavy metals
Written by: Jonathan Toker, PhD
Date: Mon Jul 26 2010
Concerned consumers have been returning containers of the named products while affected manufacturers have been working overtime to refute the CR study. As an athlete familiar with using protein supplements on a regular basis and as a Ph.D. chemist having worked in an analytical laboratory that included testing of drug product for heavy metals, I hope the following brief summary may be of assistance for concerned and confused Slowtwitch.com readers.
The CR study analyzed 15 protein samples for arsenic, cadmium, lead and mercury. The amount tested was three (3) servings as defined by the product label that ranged from 78g to 237g of powder and 990 mL to 1500mL of liquid product. CR presents their final data in the table below.
What CR found is summarized in the above table and the bold numbers clearly indicate levels of some heavy metals that exceed the published US Pharmacopoeia (USP) daily limits for adults. One of the manufacturers affected opined that the USP limits apply to a relatively low adult weight, however, USP does not provide weight/weight limits and so the static upper limit should apply in a similar way that radiation exposure is recognized as an absolute value and not related to subject weight. The dangers of accumulating heavy metals in an organism is a significant issue.
Why are these particular heavy metals of any consequence? Lead, mercury, arsenic, and cadmium fall within what are called Class 1 elemental impurities. These elements should be essentially absent as they are known or strongly suspected human toxicants and environmental hazards. In the world of pharmaceutical drugs, due to their unacceptable toxicities or deleterious environmental effects, Class 1 impurities should not be present in a drug substance, excipient, or drug product.
Heavy metals testing is actually a very simple and straightforward analytical procedure. While the CR report does not identify the methods used for testing, it is reasonable to expect that standard laboratory methods have been followed, including correct calibration and reference materials. The fact that some of the samples tested demonstrated levels of heavy metals below the detection limit of the method tends to suggest that no exogenous source (sample matrix, etc...) added any metal content, and the values presented are likely valid. However, CR should have disclosed additional information on its testing protocol.
While that may be the case for some athletes, it would be been much more representative to compare the products by weight and not by serving size. A comparison by weight would have leveled the results and the products that exceeded the USP limits would likely have passed scrutiny. CR did a disservice to its readership by ignoring the serving weights. Rigorous scientific studies should be based on fact and the results in CR are probably factual but presented in a misleading manner. I have taken it upon myself to recreate the CR solid protein results from their table, standardizing a 3-serving daily intake to 100g of powder. The results are:
As you can see by the table, consuming less that 100g of any of these supplements tested falls below USP limits and would not have generated any of the news headlines. However, the fact remains that some of these products DO contain heavy metals according to the testing and long term or excessive use could result in accumulation of heavy metals in athlete's bodies. So it would appear the point of the article may have been more accurately to highlight the presence and dangers of heavy metals in some products, but not to ring alarm bells that these values exceed any particular threshold. With a large enough sample size just about any substance will reveal its impurities.
In the opinion of this writer, both CR and the affected manufacturers should work together for better communication and more rigorous scientific scrutiny. The published research is a "good start" but clearly additional studies are needed. CR may be faulted for carrying out what appears to be an incomplete and poorly-designed study and the manufacturers may be chastised for allowing any detectable level of heavy metals into their products when alternative raw material sources exist with lower levels of metals. However, it's through scrutiny such as this study that these issues come to light and all parties involved can make efforts towards safer products.
Based on the CR report, at this time there is no clear evidence that protein supplements are of significant danger in "normal" usage quantities. However, it is reasonable to exercise caution when consuming excessive protein supplements and to limit daily intake to less than 100g per day, a level that still exceeds normal protein requirements for active individuals. Pregnant women and smaller individuals (including children and teens) should be particularly careful and refrain from excessive protein supplement intake.
It is also helpful to remember that many foods contain natural levels of metals and that it is impossible to avoid all exposure to these heavy metals. Even when the heavy metal content remains below USP limits, when supplements are combined with normal daily food intake, it is readily possible for individuals to exceed the daily USP limits.
It is equally troubling that CR lacks rigorous data interpretation and omits the testing parameters. As a neutral organization dedicated to consumer protection, CR should consider making all data relating to its studies subject to the same public scrutiny as peer-reviewed scientific research. considering the broad-reaching effect (positive or negative) that their results can have, they owe it to their readers to reach for the highest uncompromising standards. And as with all nutritional supplements, consumers should weigh the benefits and risks of consumption and make informed choices whenever possible.
Eating lots of broccoli can only take one so far. How does one go about gaining quantitative insight into the nutritional state of the body? Enter the latest high-tech and exhaustive performance nutrition testing. 8.23.11
Reviewed by: Li, Apr 6 2011 7:09PM
Secondly, the fact that the data table uses the amount in three servings is rather misleading because many people might not realize how much it actually is.
In any case, this is a great review in that it does not jump to conclusions on that heavy metals in these protein products automatically make them unusable.
Protein Intake and Brands Studied
Reviewed by: Darin Shearer, Aug 5 2010 8:23AM
The study is useless to me as an endurance athlete since I'm a snob and don't shop at GNC. I think a lot of readers of ST would be interested to see what heavy metals are contained in brands that are marketed toward the endurance athlete: Hammer Nutrition, Endurox, Powerbar, Gu, etc. Anyone want to fund that study?
Drinking heavy metals
Reviewed by: doug in co, Aug 2 2010 1:06PM
That is true but irrelevant. We don't consume the products by weight, we consume them by the manufacturer's recommended serving size. CR's test protocol seems entirely appropriate to me, so the suggested test protocol by weight is the misleading one.
Reviewed by: Sharon Sheremeta, Aug 2 2010 12:33PM
Reviewed by: Audrey, Jul 26 2010 7:28PM