Clients often seek out their personal trainers’ opinions on the best protein powder to consume following tough workouts. This seems like such a harmless and expected inquiry since so many trainers work out arduously themselves and are happy to endorse their favorite products. However, much controversy seems to surround the purity of protein products as of late. Are trainers stepping outside their scope of practice to recommend a powder?

If you are inclined to make a recommendation, are you aware of the current legal climate regarding heavy metals found within many protein supplements? We already know that artificial sweeteners are a hidden culprit contained within most popular protein powders and bars. Is it even safe to supplement with protein when such health risks are being intimated from varying sources?

Watchdog Findings of Heavy Metals

A private group called the Clean Label Project identified and analyzed the top 134 protein powder formulas for high levels of heavy metals and other toxins. The search included powders from a variety of protein sources: egg, whey and plant-based. The Clean Label Project enlisted the help of Ellipse Analytics, a fairly new independent laboratory, to conduct tests for arsenic, lead, BPA, and cadmium, among other materials.

It was determined that plant-based proteins contained higher amounts of certain heavy metals than those derived from either whey or egg protein. Such products have been popping up on the market in abundance to meet the needs of an ever-increasing population of vegan and vegetarian athletes. As expected, there was a public outcry as soon as the Project revealed its data.

Natural Products Association (NPA) pushed back, claiming uncertainty regarding sources of funding for the research, thereby implying that it remained unclear who stood to profit from such revelations. Executive Director Dan Fabricant, PhD, felt that the mere presence of trace amounts of heavy metals was made to seem like a dire health threat.

Sunwarrior, a leading producer of vegan plant-based protein powders, likewise fought back against the recent edict. Spokesperson Susanna Kaines informed the scientists at Clean Label Project that a vegetable as common as spinach may naturally contain up to 60 mcg of cadmium, and that even this amount is well below the federally mandated allowable amount per serving.

Andrea Wong, PhD, a toxicologist and Vice-President of Scientific and Regulatory Affairs at the Council for Responsible Nutrition, pointed out that “A detectable level of a contaminant is not necessarily an unsafe level; it merely means that the instrumentation used for testing was sophisticated enough to detect it.” Dr. Wong also noted that plant-based protein powders will reflect minerals absorbed from the soil, yet these are all naturally occurring substances.

A Matter of Dosage

“The advent of mass spectrometry techniques has greatly increased the reliability of analytical methods” said James Neal Kababick, founder of Flora Research Laboratories in Oregon. He reminded researchers to consider the dosage and not merely the presence of a compound; therein lies the most significant difference in toxicity levels.

Kababick does not necessarily believe that a life-threatening situation had been unleashed upon the unsuspecting public. Rather, he claimed that such reporting “…is only creating confusion and clouding the issue.”

Clearly the Clean Label Project feels the word must get out regarding what potential dangers lurk in the best-selling brands of protein powders. The company claimed to be thinking about a bigger picture in reporting their findings, or what health risks may develop over the course of 20 years of product use.

The Truth Behind Toxicity

Vega is another top-selling retailer of plant-based protein powders. The company conducts its testing for the heavy metals lead, arsenic, mercury, and cadmium utilizing a process known as ICP/MS (inductively coupled plasma/mass spectroscopy). A highly sophisticated process such as this is able to detect heavy metals at concentrations as low as one part per quadrillion.

It is among the most powerful methods in the industry for trace element detection. Therefore, it becomes possible to detect metals at levels well below regulatory thresholds and therefore much less than any risk-causing amount.

The company maintains that the level of detectable heavy metals in their products are at levels expected among minimally-processed plant products and fall within the government thresholds of what is safe for human consumption. 

California’s Proposition 65, which monitors consumer exposure to chemicals, allows for safe amounts of certain compounds – including heavy metals — to be present in a product. The proposition refers to these amounts as “safe harbor” levels, which are based upon an average consumer’s daily exposure level

Such calculations are highly complex, requiring expert analysis. It is the government’s belief that such variables were most likely not taken into account by the Clean Label Project. Applying appropriate and approved guidelines for proper, accepted scientific and statistical analysis ensures that Vega’s products are within this “safe harbor”.

“Chronic” Is Critical

While not all exposure to heavy metals presents a risk of harm, there are certain heavy metals that can be toxic to human health in cases of chronic or high-level exposure. Lead, cadmium, arsenic and mercury are the compounds that have come under recent scrutiny. Lead is involved in many manufacturing processes and can be found in paint (especially pre-1988), cosmetics and toys.

Cadmium is often used in television screens, lasers, batteries, paint pigments, and cosmetics. Arsenic can be detected in the air, water and earth. Mercury is released following volcanic activity, erosion and from various human activity involved with land.

Because heavy metals are also commonly found in nature, including in the soil, they can be present in many foods we find at a local grocery store. Recognizing this fact, the FDA published a study on minerals and heavy metals such as arsenic, mercury, cadmium and lead, including their presence in a variety of foods. Below are some examples of their findings:

  • 1 large cucumber may contain 3.08mcg arsenic
  • 2 cups of strawberries may contain an average of 4.56mcg cadmium
  • Adding 2 cups of spinach into a smoothie equates to in 0.24mcg lead

Simply because there may be detectable amounts of heavy metals in these foods does not render them unsafe to consume, nor does it detract from the benefits derived by including them in a regular meal plan, such as fiber and antioxidants from spinach and berries, or vitamins and minerals found in cucumbers.

Some professionals disapprove of consuming protein powder supplementation, regardless of the level of heavy metals contained therein. “I don’t recommend using protein powders except in a few instances, and only with supervision,” says registered dietitian Kathy McManus, Director of the Department of Nutrition at Harvard-affiliated Brigham and Women’s Hospital.

That has not seemed to slow down the industry, however. More and more supplement companies appear on the Internet each month. It is a daunting task to sort out what information is reliable, and therefore what answers to give our clients who pose questions/concerns regarding protein powder choices.

Government Control

The FDA actively monitors levels of heavy metals in our food supply. They take a systematic approach to reduce the risks posed by these metals, taking into consideration vulnerable populations such as infants and children, who are most susceptible to some of the harmful neurological and developmental effects of these compounds.

Understanding the risk these metals pose in our food supply is complicated by the fact that no single food source accounts for most people’s exposure to metals in foods. Exposure comes from many different foods, each containing low levels of these metals. Combining all of these minimal-level foods, not to mention the aforementioned products, may potentially add up to a level of concern over time.

A branch of the FDA known as Toxic Elements Working Group aims to reduce exposure to toxic elements in food, cosmetics and dietary supplements. The group is made up of senior leaders and risk managers within the Center for Food Safety and Applied Nutrition (CFSAN), who have combined experience in microbiology, toxicology, chemistry, medicine, epidemiology, policy and law.

Working with these professionals, the group tackles the issues presented by metals through a wide range of policies and actions. Such procedures include requiring or encouraging industry to take steps to reduce the presence of the metals in products, as well as educating consumers about ways they can reduce their risks.

Are Other Countries More Cautious?

Countries throughout the world differ in their approach to regulation of health products. Canadian manufacturers, for example, must get a product license from Health Canada to sell their products within the country. Health Canada assesses the product to consider its safety, efficacy and quality. Only upon passing such stringent testing will Health Canada issue a license.

In the United States, dietary supplements are considered to be food products under the Dietary Supplements Health Education Act. A protein powder is a dietary supplement. The FDA leaves it up to manufacturers to evaluate the safety and labeling of products. In the absence of federal testing, there is no surefire way to know if a protein powder contains what manufacturers claim.

These products are not subject to mandatory review, approval or quality requirements, and do not go through testing for identity, purity or potency of active ingredients. Often these supplements cannot be sold in Canada, due to the lesser restrictiveness of the FDA. However, many Canadian protein powders are available for sale in the United States through the Internet.

On A Personal Note

As a microbiologist and competitive bodybuilder, I have made adjustments to my own choices of plant-based protein powders in response to this research. It remains my contention, however, that the purity of such products rests largely in the microfiltration procedure and the temperature at which this is performed. Bioavailability of the protein source is also a key factor in my decision process.

Once these parameters have been adequately satisfied, I do not dwell upon the issue of heavy metals in such products. At ½ serving of protein powder per day, coupled with an otherwise clean meal plan consisting of fish, vegetables and plant-based whole-food protein sources (tofu, hummus, tahini, etc.), my belief is that any heavy metal presence will be adequately diluted out at the end of the day’s total consumption.



Cathleen Kronemer

Cathleen Kronemer is an NFPT CEC writer and a member of the NFPT Certification Council Board. Cathleen is an AFAA-Certified Group Exercise Instructor, NSCA-Certified Personal Trainer, ACE-Certified Health Coach, former competitive bodybuilder and freelance writer. She is employed at the Jewish Community Center in St. Louis, MO. Cathleen has been involved in the fitness industry for over three decades. Feel free to contact her at She welcomes your feedback and your comments!