Nutrition
Contamination in protein supplements and drinks: should we be concerned?
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MPH, MSc
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A new analysis of protein supplements by Consumer Reports published in October 2025 discusses the problem of heavy metals in these types of products. We analyze the report, its strengths, and its limitations and contextualization regarding the issue of lead contamination.
Despite being a known problem for decades, according to the new report, heavy metal contamination appears to be increasingly common, having increased in this latest analysis compared to other analyses conducted in previous years.
More than two-thirds of the products analyzed show levels of lead in a single serving that exceed what Consumer Reports food safety experts consider safe to consume in a day. Some of the products analyzed showed levels ten times higher, exceeding in a single serving the average daily intake of lead that a person ingests through food.
"The lead levels in plant-based products were, on average, nine times the amount found in those made with dairy proteins like whey."
While we agree that the general population would benefit from increasing their consumption of fresh plant foods, there is a certain mystique surrounding certain types of plant products and supplements that does not correspond to reality.
As for the specific role of protein, we do not entirely agree with the approach taken by the Consumer Reports report, given that, under the criteria used, many everyday foods would also fail the test. Therefore, much of what is sold in supermarkets could be explicitly labeled, and it is necessary to put these levels into perspective in relation to a person's total daily exposure.
While it is true that we should ingest as little as possible, the lead that can be ingested through protein powder supplements is also being ingested to a greater or lesser extent with other foods. Most supplements only account for a portion of an individual's average daily lead intake, so eliminating protein supplementation from the diet will not stop people from being exposed to lead levels that will remain equally significant. Therefore, the findings must take into account people's overall dietary context.
Another problem with the Consumer Reports report is that comparisons of lead levels found are not reported gram for gram, but by doses that vary quantitatively up to 10 times depending on the product. A significant number of the products reported do not represent a typical protein dose (approximately 25-30 g of protein), but rather are products intended to increase calories (mass gainers, etc.), whose recommended dose exceeds 300 g of powdered product. Therefore, doses of only 25 g are being compared with others of more than 300 g of product.
While it is true that the portions are generally recommended by the products themselves, reporting lead levels "per dose" can be confusing and must be properly contextualized.
However, a number of protein products have lead levels that may exceed the average that a person would obtain through all the food they eat throughout the day, even with a relatively low number of servings. This comparative criterion, rather than the absolute criterion proposed, allows for a more contextualized understanding of the reality, highlighting those products that require serious consumption restrictions. The analysis is also interesting in that it shows that powdered vegetable protein sources present more problems and should be treated with greater caution. People who consume powdered vegetable protein should therefore reconsider their intake.
In short, the Consumer Reports report does not show that there is an alarming situation with most protein supplements in typical doses compared to what is ingested in an average diet. However, it does show that these types of products can have significant levels of heavy metals, which in some specific cases can be very high, so heavy consumers of these products should moderate their intake. A fitness enthusiast can easily consume several daily doses of protein powder, which can add up to a substantial amount of lead and other metals. But the same may be true for a significant number of people who consume protein products in a growing market in the everyday food sector. The overvaluation of protein for muscle growth is a topic for another article that we will not address here.
Additionally, it is possible that some of the heavy metal contamination comes from other raw materials used, such as cocoa. While this analysis has not found significant differences in flavor, it has been common to find higher levels of contaminants in protein products that use cocoa, in various analyses carried out by different laboratories. Cocoa acts as a vector for heavy metals due to soil contamination in tropical regions, although this is mainly due to post-harvest manufacturing and transportation processes.
Controlling the origin of the raw material is what most reduces the risk (soil assessment, farm design, audits, traceability, filtered process water, etc.). It is likely that some suppliers resort to mixing batches to achieve "acceptable" averages. However, there is an explicit ban (or severe restrictions) on the use of chemicals to "clean" food or food raw materials contaminated with heavy metals, mycotoxins, etc. Potential methods could be biological, through sequestration by yeasts or bacteria. However, this still needs to be developed.
The other issue is the ability of the law to respond, given its erosion by current administrative positivism, which progressively reduces justice to mere political decision-making (visibly distracted when it comes to acting on issues that are uncomfortable for the establishment). There have been some rulings on certain dietary products contaminated with lead and other metals, and some companies have been legally required to take measures to reduce the levels of lead in their products before selling them to the public, which involves verifying raw material suppliers and establishing systematically traceable quality controls. Therefore, there are court rulings on this matter with a sense of positive pragmatism.
Humans have never been exposed to lead throughout their history, except at a very residual and biologically insignificant level, so all human exposure comes from pollution. The main problem with this type of pollutant is its bioaccumulation: once it enters the body, it is not easily eliminated. Thus, lead can remain accumulated in the body for decades, with a progressive accumulation effect and problematic release at certain stages of life such as pregnancy and breastfeeding. Thus, a significant portion of blood lead levels comes from tissues such as bone, from which it is released.
Therefore, there is no biologically safe threshold for this type of contaminant. It is difficult, and often misleading, to talk about "safe" levels of toxic substances. The simplistic use of Paracelsus's formulation, which actually comes from the much older pharmakon view, has sought to eliminate precisely its original paradoxical and dialectical character in order to create a positivist and reductionist view of dosage, which is completely mistaken and has been used to obscure the problem of the persistence and accumulation of contaminants that are deadly, even at low doses. The neglect of the ambivalent nature of pharmakon has allowed toxicology to be converted into a standardized statistic that legalizes not only poisons but also environmental crimes.
From some comments received over the years, it seems that a number of nutritionists believe that these problems do not occur in Spain or the European Union because "the regulations are stricter." This is confusing the nominal with reality. Many of these brands are distributed directly in Europe, and some suppliers of the raw materials for these proteins are in fact European in the first place, while much of the raw materials used to make plant proteins tend to come from countries such as China or India. The EU sets maximum limits for lead in food, but these limits do not mean that there is no problem in the first place.
In terms of regulatory compliance, the European Commission itself shows that only 0.0082% of all imported products are inspected. Of the products inspected, a large proportion are found to have problems and fail the inspection, revealing a structural operation that allows a massive influx of problematic products into the EU, regardless of how many laws are in place.
Regulation is therefore based more on theory and documentation than on actual verification. On the other hand, any possible requirement for certificates of analysis can be handled by means of selective batches. In the event of unfavorable results, companies can question the conditions under which the analytical method was carried out, the lack of standardization, the sampling, which is only an isolated batch that does not represent the total volume, etc., to cite common responses. They may even submit false certificates of analysis.
As someone who has been subscribed to laboratories that have privately analyzed protein for more than 15 years, we are simply facing a consistently proven reality. The absence of published reports does not mean the absence of contamination problems, especially when this exposure is simply an environmental fact. The existence of legal limits is not necessarily the reality of a population's exposure, nor is it really a safety criterion; it only defines the threshold at which a problem officially becomes uncomfortable.
"The maximum amount of lead allowed in food supplements according to the EFSA is 3,000 ppb (3 mg/kg), a level that Consumer Reports food safety experts consider too high to be truly protective of health."
The strongest evidence is probably found empirically when comparing studies measuring lead levels in the body in the United States and Europe, which do not seem to show much difference. This shows a gap between legal formulation and material reality.
https://www.epa.gov/americaschildrenenvironment/biomonitoring-lead
https://www.mdpi.com/1660-4601/18/4/1825
https://www.sciencedirect.com/science/article/abs/pii/S004896970901...
• There is no widespread alarming problem with protein supplements, although it is true that they can contain significant amounts of lead, which should be considered in the context of common dietary exposure.
• A relative minority of brands analyzed have very high levels of lead, indicating quality control issues.
• Plant-based protein supplements present more problems and require greater attention.
• People who consume a lot of protein from supplements and drinks should increase their protein intake from food and take more moderate amounts of supplements.
• Technology exists to substantially reduce heavy metals. In principle, more filtered proteins should have fewer contaminants, and people should possibly choose them.
• We think it is reasonable to mention the current overvaluation of food products promoted with the claim of protein. Most people do not benefit from eating as much protein as they think.
Additionally, to build muscle mass, the stimulus produced on the muscle by strength training is much more important than the intake of extra protein or protein supplements. The scientific evidence in this regard is much more modest than most people seem to assume. But that is another issue and we will leave it for another article. Our advice in any case is to eat more protein from food and reduce the amount of supplements.
THE CONSUMER REPORTS REPORT
A recent analysis by Consumer Reports including 23 samples of protein powders and ready-to-drink protein shakes from popular brands has shown a frequent presence of lead in these types of products. This report is consistent with previous reports by other independent groupsDespite being a known problem for decades, according to the new report, heavy metal contamination appears to be increasingly common, having increased in this latest analysis compared to other analyses conducted in previous years.
More than two-thirds of the products analyzed show levels of lead in a single serving that exceed what Consumer Reports food safety experts consider safe to consume in a day. Some of the products analyzed showed levels ten times higher, exceeding in a single serving the average daily intake of lead that a person ingests through food.
PLANT PROTEINS: A HEALTHIER OPTION?
Paradoxically, many consumers choose plant proteins because they perceive them to be healthier. However, high levels of contaminants have been found in almost all plant-derived protein products, in fact much higher than in other types of protein. The Consumer Reports report itself concludes:"The lead levels in plant-based products were, on average, nine times the amount found in those made with dairy proteins like whey."
While we agree that the general population would benefit from increasing their consumption of fresh plant foods, there is a certain mystique surrounding certain types of plant products and supplements that does not correspond to reality.
OUR OPINION ON THE REPORT
The Consumer Reports report points to an important and highly silenced public health issue: there is no safe level of lead exposure, and neurological and cardiovascular damage occurs even at the lowest detectable concentrations, resulting in millions of deaths each year. Even at low doses, lead exposure is a silent problem that is more serious than it might seem.As for the specific role of protein, we do not entirely agree with the approach taken by the Consumer Reports report, given that, under the criteria used, many everyday foods would also fail the test. Therefore, much of what is sold in supermarkets could be explicitly labeled, and it is necessary to put these levels into perspective in relation to a person's total daily exposure.
While it is true that we should ingest as little as possible, the lead that can be ingested through protein powder supplements is also being ingested to a greater or lesser extent with other foods. Most supplements only account for a portion of an individual's average daily lead intake, so eliminating protein supplementation from the diet will not stop people from being exposed to lead levels that will remain equally significant. Therefore, the findings must take into account people's overall dietary context.
Another problem with the Consumer Reports report is that comparisons of lead levels found are not reported gram for gram, but by doses that vary quantitatively up to 10 times depending on the product. A significant number of the products reported do not represent a typical protein dose (approximately 25-30 g of protein), but rather are products intended to increase calories (mass gainers, etc.), whose recommended dose exceeds 300 g of powdered product. Therefore, doses of only 25 g are being compared with others of more than 300 g of product.
While it is true that the portions are generally recommended by the products themselves, reporting lead levels "per dose" can be confusing and must be properly contextualized.
However, a number of protein products have lead levels that may exceed the average that a person would obtain through all the food they eat throughout the day, even with a relatively low number of servings. This comparative criterion, rather than the absolute criterion proposed, allows for a more contextualized understanding of the reality, highlighting those products that require serious consumption restrictions. The analysis is also interesting in that it shows that powdered vegetable protein sources present more problems and should be treated with greater caution. People who consume powdered vegetable protein should therefore reconsider their intake.
In short, the Consumer Reports report does not show that there is an alarming situation with most protein supplements in typical doses compared to what is ingested in an average diet. However, it does show that these types of products can have significant levels of heavy metals, which in some specific cases can be very high, so heavy consumers of these products should moderate their intake. A fitness enthusiast can easily consume several daily doses of protein powder, which can add up to a substantial amount of lead and other metals. But the same may be true for a significant number of people who consume protein products in a growing market in the everyday food sector. The overvaluation of protein for muscle growth is a topic for another article that we will not address here.
POTENTIAL SOLUTIONS
One of the reasons why plant proteins have higher levels of contaminants is that dairy proteins such as whey are manufactured using filtration processes that reduce a large part of the contaminants. For this same reason, some proteins subjected to more intensive filtration processes should have fewer contaminants (nanofiltration, ion exchange, etc.). It would be good if this type of comparative analysis took this aspect into account more often. There are therefore technologies and physical methods of molecular separation that can be used effectively. Although commonly used in milk proteins, in practice they are not widely used in plant proteins. This is partly because they are more difficult to apply to this raw material.Additionally, it is possible that some of the heavy metal contamination comes from other raw materials used, such as cocoa. While this analysis has not found significant differences in flavor, it has been common to find higher levels of contaminants in protein products that use cocoa, in various analyses carried out by different laboratories. Cocoa acts as a vector for heavy metals due to soil contamination in tropical regions, although this is mainly due to post-harvest manufacturing and transportation processes.
Controlling the origin of the raw material is what most reduces the risk (soil assessment, farm design, audits, traceability, filtered process water, etc.). It is likely that some suppliers resort to mixing batches to achieve "acceptable" averages. However, there is an explicit ban (or severe restrictions) on the use of chemicals to "clean" food or food raw materials contaminated with heavy metals, mycotoxins, etc. Potential methods could be biological, through sequestration by yeasts or bacteria. However, this still needs to be developed.
The other issue is the ability of the law to respond, given its erosion by current administrative positivism, which progressively reduces justice to mere political decision-making (visibly distracted when it comes to acting on issues that are uncomfortable for the establishment). There have been some rulings on certain dietary products contaminated with lead and other metals, and some companies have been legally required to take measures to reduce the levels of lead in their products before selling them to the public, which involves verifying raw material suppliers and establishing systematically traceable quality controls. Therefore, there are court rulings on this matter with a sense of positive pragmatism.
HEAVY METALS IN FOOD: A MISUNDERSTOOD TOXICOLOGICAL PROBLEM
Although the Consumer Reports report was compiled using samples of products obtained in the United States, this does not mean that we are not in fact facing a global problem that affects Europe and Spain.Humans have never been exposed to lead throughout their history, except at a very residual and biologically insignificant level, so all human exposure comes from pollution. The main problem with this type of pollutant is its bioaccumulation: once it enters the body, it is not easily eliminated. Thus, lead can remain accumulated in the body for decades, with a progressive accumulation effect and problematic release at certain stages of life such as pregnancy and breastfeeding. Thus, a significant portion of blood lead levels comes from tissues such as bone, from which it is released.
Therefore, there is no biologically safe threshold for this type of contaminant. It is difficult, and often misleading, to talk about "safe" levels of toxic substances. The simplistic use of Paracelsus's formulation, which actually comes from the much older pharmakon view, has sought to eliminate precisely its original paradoxical and dialectical character in order to create a positivist and reductionist view of dosage, which is completely mistaken and has been used to obscure the problem of the persistence and accumulation of contaminants that are deadly, even at low doses. The neglect of the ambivalent nature of pharmakon has allowed toxicology to be converted into a standardized statistic that legalizes not only poisons but also environmental crimes.
From some comments received over the years, it seems that a number of nutritionists believe that these problems do not occur in Spain or the European Union because "the regulations are stricter." This is confusing the nominal with reality. Many of these brands are distributed directly in Europe, and some suppliers of the raw materials for these proteins are in fact European in the first place, while much of the raw materials used to make plant proteins tend to come from countries such as China or India. The EU sets maximum limits for lead in food, but these limits do not mean that there is no problem in the first place.
In terms of regulatory compliance, the European Commission itself shows that only 0.0082% of all imported products are inspected. Of the products inspected, a large proportion are found to have problems and fail the inspection, revealing a structural operation that allows a massive influx of problematic products into the EU, regardless of how many laws are in place.
Regulation is therefore based more on theory and documentation than on actual verification. On the other hand, any possible requirement for certificates of analysis can be handled by means of selective batches. In the event of unfavorable results, companies can question the conditions under which the analytical method was carried out, the lack of standardization, the sampling, which is only an isolated batch that does not represent the total volume, etc., to cite common responses. They may even submit false certificates of analysis.
As someone who has been subscribed to laboratories that have privately analyzed protein for more than 15 years, we are simply facing a consistently proven reality. The absence of published reports does not mean the absence of contamination problems, especially when this exposure is simply an environmental fact. The existence of legal limits is not necessarily the reality of a population's exposure, nor is it really a safety criterion; it only defines the threshold at which a problem officially becomes uncomfortable.
"The maximum amount of lead allowed in food supplements according to the EFSA is 3,000 ppb (3 mg/kg), a level that Consumer Reports food safety experts consider too high to be truly protective of health."
The strongest evidence is probably found empirically when comparing studies measuring lead levels in the body in the United States and Europe, which do not seem to show much difference. This shows a gap between legal formulation and material reality.
https://www.epa.gov/americaschildrenenvironment/biomonitoring-lead
https://www.mdpi.com/1660-4601/18/4/1825
https://www.sciencedirect.com/science/article/abs/pii/S004896970901...
OUR CONCLUSIONS
Consumer Reports' analysis is generally consistent with various independent analyses conducted over the years, showing that protein supplements have significant levels of heavy metals such as lead and others.• There is no widespread alarming problem with protein supplements, although it is true that they can contain significant amounts of lead, which should be considered in the context of common dietary exposure.
• A relative minority of brands analyzed have very high levels of lead, indicating quality control issues.
• Plant-based protein supplements present more problems and require greater attention.
• People who consume a lot of protein from supplements and drinks should increase their protein intake from food and take more moderate amounts of supplements.
• Technology exists to substantially reduce heavy metals. In principle, more filtered proteins should have fewer contaminants, and people should possibly choose them.
• We think it is reasonable to mention the current overvaluation of food products promoted with the claim of protein. Most people do not benefit from eating as much protein as they think.
Additionally, to build muscle mass, the stimulus produced on the muscle by strength training is much more important than the intake of extra protein or protein supplements. The scientific evidence in this regard is much more modest than most people seem to assume. But that is another issue and we will leave it for another article. Our advice in any case is to eat more protein from food and reduce the amount of supplements.
#proteinsupplements #heavymetals #foodcontamination #whey
References:
Consumer Reports. (2025). Protein powders and shakes contain high levels of lead. https://www.consumerreports.org/lead/protein-powders-and-shakes-con...
Becerra, X. (2019, August 19). Attorney General Becerra announces settlement against Newport Beach company for selling products with high lead levels. Office of the Attorney General, California Department of Justice. https://oag.ca.gov/news/press-releases/attorney-general-becerra-ann...
Consumer Reports. (2023). Lead and cadmium in dark chocolate. https://www.consumerreports.org/health/food-safety/lead-and-cadmium...
European Commission. (2023). Regulation (EU) 2023/915 of the European Parliament and of the Council of 25 April 2023 on maximum levels for certain contaminants in foodstuffs. Official Journal of the European Union. https://eur-lex.europa.eu/legal-content/es/ALL/?uri=CELEX:32023R0915
European Commission. (2025). Report on the implementation of official controls on imported food and feed. Publications Office of the European Union. https://op.europa.eu/en/publication-detail/-/publication/ea5db20e-8...
Gulson, B. L., Mizon, K. J., Palmer, J. M., Korsch, M. J., & Taylor, A. J. (2003). Contribution of skeletal lead to blood lead during pregnancy and lactation. Science of the Total Environment, 303(1-2), 79-104. https://doi.org/10.1016/S0048-9697(02)00355-8
Lanphear, B., Navas-Acien, A., & Bellinger, D. C. (2024). Lead Poisoning. The New England journal of medicine, 391(17), 1621-1631. https://doi.org/10.1056/NEJMra2402527
Ma X. (2024). Heavy metals remediation through lactic acid bacteria: Current status and future prospects. The Science of the total environment, 946, 174455. https://doi.org/10.1016/j.scitotenv.2024.174455
Ruiz-Tudela, L., Vázquez-López, M. A., García-Escobar, I., Cabrera-Sevilla, J. E., Gómez-Bueno, S., Martín-Gonzalez, M., & Muñoz-Vico, F. J. (2021). Blood Lead Level in a Paediatric Population of South-Eastern Spain and Associated Risk Factors. International journal of environmental research and public health, 18(4), 1825.
Smolders, R., Alimonti, A., Cerna, M., Den Hond, E., Kristiansen, J., Palkovicova, L., Ranft, U., Seldén, A. I., Telisman, S., & Schoeters, G. (2010). Availability and comparability of human biomonitoring data across Europe: a case-study on blood-lead levels. The Science of the total environment, 408(6), 1437-1445. https://doi.org/10.1016/j.scitotenv.2009.11.025
U.S. Environmental Protection Agency (EPA). America's Children and the Environment: Biomonitoring-Lead. https://www.epa.gov/americaschildrenenvironment/biomonitoring-lead
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