Heavy Metals in Plant-Based Protein: Why you shouldn't listen to Consumer Reports (and What Science Says Instead)

By Joe Clark, BSc (Hons) Sport and Exercise Science 

October 20, 2025.

Introduction

If you’ve come here, you’re likely asking yourself, “Should I stop consuming plant-based protein due to heavy metals?” and that may be due to the Consumer Reports article published on October 14, 2025 titled "Protein Powders and Shakes Contain High Levels of Lead'

This is a science-based critique of the information shared by Consumer Reports, as well a detailed look at whether plant-based proteins actually contain harmful amounts of heavy metals. If you haven’t read the Consumer Reports article and are simply curious about whether plant-based proteins contain harmful amounts of heavy metals, this article is for you as well.

In this article, you’ll learn why Consumer Reports spread misinformation regarding heavy metals in plant-based proteins, focusing specifically on lead. This article is a science-based critique supported by peer-reviewed research that is referenced and linked throughout. It’s the kind of evidence-based approach Consumer Reports should have taken — rather than relying on selective quotes from their “experts.”

Article Summary:

• Large, longitudinal, peer-reviewed studies consistently show that the average person consumes on average 140 times more lead per day than the Prop 65 'safe daily lead limit' - the backbone of the Consumer Reports article, simply through normal foods including water and vegetables (1, 2).
  
• .
• A single beetroot can contain up to 28 times the Prop 65 lead limit—and about four times that of a serving of plant-based protein (3). Lead is also common in many other fruits and vegetables, often in quantities well above the Prop 65 threshold (4).
• .
• 100 g of frozen tomatoes can contain up to 10 times more lead than a serving of plant-based protein, 58 times Prop 65's limit (3).
• .
• There can be up to 10 times more lead in a litre of drinking water in Canada than the Prop 65 limit, and up to 20 times more in the UK according to the lead limits on safe drinking water (5, 6)
• .
• Lead consumption in Canadians is not a new or emerging issue, in fact, it's the opposite with lead consumption dropping 37% since 2009 (7), meanwhile plant-based protein consumption has increased 2.4% each year (8).
• .
• For adverse health effects to occur from lead, the average Canadian would need to consume 12 times more lead per day to raise blood lead levels to CDC levels of concern (9, 10)
• .
• Consumer Reports has cherry-picked the world’s lowest and scientifically unsupported lead threshold — California’s Proposition 65 (11) — and built an entire article around it, spreading misinformation and fear to consumers.
• .
• Lead and other trace metals occur naturally in soil, water, and air, meaning all vegetables contain measurable amounts — often higher than those found in plant-based proteins (3, 4). Despite this, the article singles out plant-based protein products for reasons unknown, demonstrating an example of misleading reporting and poor journalistic integrity, with a lack of scientific rigour.

Objective of this article

This is an in-depth, scientific analysis with the objective of explaining why the Consumer Reports article is a piece of gross misinformation, so that you, the consumer, are properly informed. It is designed to be easily understandable and accessible for the average reader, while still including proper use of scientific supporting research.

Here, we’ll examine the actual lead values found in everyday foods and explain why Prop 65 has no place in real-world health and safety discussions. By the end of this article, you’ll no longer worry about the misleading information circulating in the media about heavy metals in plant-based proteins.

I’ve included a navigation section below for easy accessibility.

Navigation:

• 1. The Core Problem — Misuse of Prop 65
• 2. Putting Prop 65 in Perspective
• 3. How Prop 65 Was Created
• 4. Third-Party Testing
• 5. Analyzing Actual Research on Lead Consumption
• 6. How Much Lead Is Dangerous?
• 7. Why Is Plant-Based Protein Being Targeted?
• 8. Thinking Critically (don't believe everything you read)
• 9. Major Inaccurate Statements within the Consumer Reports Article
• 10. Thrive Protein’s Commitment to Quality and Transparency

1. The Core Problem — Misuse of Prop 65

One of the key issues is that Consumer Reports bases its entire analysis on limits set by California’s Proposition 65, rather than on any scientifically recognized health or safety standards established by agencies such as Health Canada, the European Union, or the U.K. Government.

Prop 65’s daily limit for lead of 0.5 micrograms (µg) per day is not a recognized safety limit. It’s an advisory threshold used solely for labeling purposes in California, designed to trigger a warning label if even trace amounts of a listed substance are present. It does not represent a toxic level or a health-based exposure limit. Furthermore, as you will soon discover, 0.5 micrograms of lead per day is a highly misguided threshold with no scientific backing. 

Simply put, the 0.5 µg figure used as the foundation for the Consumer Reports article’s claims is not supported by international toxicology data or actual lead consumption data. It is orders of magnitude lower than the limits accepted by the other global health authorities. 

2. Putting Prop 65 in Perspective

To put into perspective how inappropriately low Prop 65’s 0.5 µg/day guideline is, a single serving of vegetables grown in mineral-rich soil can naturally contain many times that amount of lead (1).

According to the U.S. Food and Drug Administration’s Total Diet Study (TDS) Program (FY2018–FY2020), which is part of the FDA’s continuous surveillance of elemental contaminants in foods, 3,683 food samples representing approximately 280 different food types were collected from retail locations across four U.S. regions (North, South, East, and West) and analyzed for elements including lead. 

The results, accessible here, clearly show that a vast amount of daily foods contain more lead than the Prop 65 daily limit.

Below are values taken directly from the FDAs analysis, they are reported in parts per billion (ppb), I have then calculated how much lead this provides per kg and per serving in micrograms.

Attached here is a PDF from the FDA.

Food	Lead (ppb)	Typical Serving	Approx. Lead per Serving (µg)	× Prop 65 Daily Limit (0.5 µg/day)
Raisins	9.7	40 g (¼ cup)	0.39 µg	0.8×
Spinach (Raw)	6.4	85 g (3 cups raw)	0.54 µg	1.1×
Carrots (Baby Food)	7.3	61 g (1 medium)	0.45 µg	0.9×
Peanut Butter (Creamy)	5.6	32 g (2 Tbsp)	0.18 µg	0.4×
Ham (Cured, Baked)	2.3	85 g (3 oz)	0.20 µg	0.4×
Cheese (American, Processed)	2.1	56 g (2 slices)	0.12 µg	0.2×
Frankfurter (Beef/Pork)	1.7	171 g (3 links)	0.29 µg	0.6×

 

As you can see, single servings of everyday foods place you in excess of Prop 65. A single meal containing multiple foods grown in North America would place you many times over Prop 65. 

However, we must also look at food grown outside of North America, as according to the USDA Economic Research Service, imports supplied about 59% of U.S. fresh fruit availability and about 35% of U.S. fresh vegetable availability in 2023, and Canada imports 58.2% of its produce (CAPI, 2023).

In this 2021 independent study from Europe (which I also highly encourage you to read), a wide variety of fresh and dried foods were also analyzed for lead values. The below table shows some of the fresh fruits and vegetables included and their lead levels (there are many more in the study). 

Food	Lead (µg/kg)	Typical Serving	Approx. Lead per Serving (µg)	× Prop 65 Daily Limit (0.5 µg/day)
Beetroot (Fresh)	95	150 g (1 medium beet)	14.3 µg	28×
Celery (Fresh)	31	100 g (≈ 2–3 stalks)	3.1 µg	6×
Carrot (Fresh)	27	75 g (1 medium carrot)	2.0 µg	4×
Raspberry (Fresh)	12	60 g (½ cup)	0.7 µg	1.4×
Tomato (Fresh)	16	120 g (1 medium tomato)	1.9 µg	3.8×
Pear (Fresh)	8	180 g (1 medium pear)	1.4 µg	2.8×
Strawberry (Fresh)	9	100 g (≈ 6–8 berries)	0.9 µg	1.8×
Apple (Fresh)	9	180 g (1 medium apple)	1.6 µg	3.2×

 

Many of the dried and frozen foods in the study were far beyond these levels. Notably, frozen tomatoes contained 294 micrograms of lead per kilogram — meaning that when you consume 100 g of frozen tomatoes, you’re getting 29.4 micrograms of lead (58 times the Prop 65 daily limit). Scary, right? Well, no — not really. It’s just that the Prop 65 limit is absurdly low. I could take that same threshold and write my own article titled “Heavy Metals in Tomatoes”, and it would set the internet and media alight just like Consumer Reports has. That’s how ridiculous their article truly is.

Another research study reported lead levels in leafy greens ranging from 6.35 to 20.85 mg/kg — more than 40 times higher than the Prop 65 threshold.

That means a single plate of certain vegetables could easily expose you to 3–30 µg of lead, which is 6–60 times higher than Prop 65’s “limit.”. Yet these foods are universally recognized as safe and nutritious.

So in plain English — are you going to stop eating vegetables because they exceed California’s Prop 65 threshold? Of course not.

How Much Lead is in Plant-Based Protein

A serving of Thrive Plant-Based Protein contains 3.1 µg of lead — an amount equivalent to, or even lower than, levels found in many common fruits and vegetables. Even some of the other brands labeled in the Consumer Reports article as products to “avoid,” such Naked Nutrition or Huel, are equivalent to lead quantities obtained through everyday produce. To suggest otherwise is factually inaccurate and misleading to consumers. These claims are not supported by toxicological evidence or by any recognized food safety standards, and their inclusion in this context borders on irresponsible reporting rather than objective analysis. Beyond misleading consumers, such misinformation is also damaging to the reputable businesses mentioned in the report — all of whom operate within regulatory limits, employ third-party testing, and have done no wrong to the consumer. 

To keep this analysis simple, we’ll continue to focus primarily on lead, though the same reasoning applies to cadmium, and you can use the two large studies linked above to look at the cadmium levels also. Later we'll continue to explore more scientific research, and I encourage you to also refer to the included references to form your own conclusions. Together, they clearly demonstrate just how unrealistically low the Prop 65 labeling thresholds are — and how deeply misinformed the Consumer Reports article on plant-based protein truly is.

Health Canada's Daily Lead Guideline

Health Canada states that up to 10 µg/day of lead intake serves as a guideline — 20 times higher than California’s Prop 65 labeling threshold. In reality, most people consume far more than that through everyday foods, yet this has never been identified as a serious public health concern. Why? Because lead is naturally present in the environment — in soil, water, and air — and has been for decades. It’s not a health crisis; it’s a trace element that’s been part of everyday life for a long time.

What is a health crisis, however, is the epidemic of obesity, type II diabetes, and other metabolic disorders — meanwhile protein supplementation is shown to decrease satiety, increase muscle maintenance, and improve metabolic health.

Water

UK drinking water

To protect drinking water quality, the UK government limits lead to 10 micrograms per litre of water. To put that in perspective, this allowable level is 20 times higher than California’s Prop 65 limit per litre. So, if you drank just 2 litres of water a day, you could legally consume up to 40 times the Prop 65 threshold — from water alone. Bear in mind, for much of the last century, lead pipework was used almost universally in plumbing. By Prop 65’s standard, that level of exposure should have rendered entire generations infertile — yet, clearly, it didn’t. This highlights just how disconnected Prop 65’s 0.5 µg/day threshold is from real-world toxicology and population health data. I am by no means saying our water contains even close to 10 micrograms per litre, what I am highlighting here is that this is the safety threshold in which the UK takes action, and it's 20 times that of Prop 65. 

Canadian Drinking Water

As mentioned before, Health Canada is stricter than most; therefore, the current water limit for lead is 5 micrograms per litre - 10 times Prop 65’s daily dose per litre. Again, I’m not saying, by any means, that water contains this much lead on average, but this value is based on — to quote Health Canada — “lead (levels) established by the World Health Organization (WHO) at a level that showed no increase in blood lead levels and thus no expected increase in health risks.”

So, if both the UK and Health Canada have limits of 10 and 20 times that of Prop 65, where is Prop 65 getting its values from?

3. How Prop 65 Was Created

If you’re interested in how Prop 65 was created, here we'll look at the method. 

California’s Prop 65 limit of 0.5 µg of lead per day was not based on evidence of actual harm at that level. The state agency that created it, OEHHA, started with studies showing reproductive effects at much higher exposures, then back-calculated a daily intake and applied huge safety margins—often around 1,000-fold— to reach an “ultra-safe” number. In other words, 0.5 µg/day is a legal warning threshold, not a biologically defined toxic dose. It exists to guarantee that even the most exaggerated, lifelong exposure would still pose an insignificant risk, which is why it ends up being over 20 times lower than limits used by agencies such as Health Canada, the UK Health Security Agency, and the WHO.

In most scientific risk assessments, uncertainty factors of 30–100× are applied to account for biological and population variability. Proposition 65, however, legally enforces a 1,000× reduction, turning valid toxicological data into a value that’s scientifically and statistically meaningless in practical terms.

Consumer Reports (who clearly did no background research of their own) then cherry-picked this value and used it to attack an entire industry.

If you want to dig further into Prop 65, in the appendix (view here), I detail their exact method in more detail. 

Prop 65 Section Summary

By treating Prop 65’s warning threshold as a universal safety standard, the Consumer Reports article misleads readers and spreads gross misinformation about product safety.

Prop 65 is a state-specific labeling law, not a global safety guideline. Its values are not endorsed by Health Canada or any other major toxicology authority.

For accurate, science-based guidance, consumers should rely on trusted public health institutions and actual toxicology research. 

• Centers for Disease Control and Prevention 2024: Blood Lead Level Guidance
• Agency for Toxic Substances and Disease Registry: Toxicological Profile for
  Lead
• Health Canada: Quality of Natural Health Products Guide
• European Union: Commission Regulation (EU) 2023 
• FAO/WHO: Codex Alimentarius Commission

You can clearly see, by reviewing all of the above validated research and guidelines, that Proposition 65 has no place in this circumstance. 

4. Third-Party Testing

Like many reputable Canadian supplement companies, we at Thrive Protein employ independent third-party batch testing — the same analytical process used in the Consumer Reports article. Our results consistently fall well below Health Canada’s limits, which are among the most stringent and protective in the world when it comes to consumer health and product safety.

You can learn more on our commitment to quality and safety in section 10, but for now, we’ll move on to other issues raised in the Consumer Reports article.

We’re also in the process of publishing all of our third-party testing results publicly on our website. In the meantime, if you’d like to review them, please reach out and we’ll gladly share them with you.

5. Analyzing Actual Research on Lead Consumption

Below I go into detail on a few studies that show how much lead we typically consume each day through diet. But first, here is a summary of the studies:

Study 1: Analyzed 144,206 food samples (2003–2010) and found across Europe, adults consume about 0.68 µg of lead per kg body weight per day, equivalent to 47.6 µg/day for a 70 kg adult (approximately 95 times Prop 65 limit of 0.5 µg/day.) The lead occurred from ordinary foods including bread, tea, and water.

Study 2: Large-scale 2010 review found that Europeans consume about 0.36–2.43 µg of lead per kg body weight per day from food — hundreds of times higher than California’s Prop 65 limit — yet without evidence of population-wide toxicity. For a 70kg adult, this equates to 25–170 µg of lead per day, 50 to 340 times higher than California’s Prop 65 limit of 0.5 µg/day.

Study 3: Children and adults in Jinhu, China consumed 8–16 µg of lead per kg body weight per week, which equates to ~88–157 µg of lead per day — 176–314× higher than California’s Prop 65 limit of 0.5 µg/day.

Study 4: In the US, lead content in milk, eggs, meat, fish, and shellfish varied from 0.02 to 0.4 ppm as far back as the 1970s, equivalent to 20–400 µg of lead per kg of food eaten (40-800 times Prop 65). They also reported 0.20-0.25 ppm of lead in formula, which would be 6 times Prop 65’s limit in a single 15g serving.

Study 5: This Korean study found that children consumed about 0.34 µg/kg/day of lead—roughly 23 µg/day for an adult equivalent (46 times Prop 65).

Study 6: 15,000 German adult participants were analyzed, finding between 0.53–0.72 µg of lead per kg body weight per day—roughly 37–50 µg daily for a 70 kg adult, or around 75–100 times higher than California’s Prop 65 limit.

Before you think, “these studies aren’t from Canada,” that doesn’t actually matter — the majority of the food we consume is imported and grown abroad, 58.2% in fact, meaning the lead levels reported in international studies are highly relevant regardless of geographic location.

So how much lead are you consuming each day? If we average all of the data above, across multiple international studies, the average adult consumes approximately 70 µg of lead per day — roughly 140 times Prop 65’s daily limit— largely from ordinary foods like bread, tea, vegetables, and water.

Looking in depth at studies

Study 1:
A large longitudinal study from EFSA examined 144,206 analytical results for lead in food collected over a nine-year period. The results found that mean lifetime dietary exposure was estimated at 0.68 µg/kg body weight per day (EFSA, 2010). If you weigh 70 kg, this equates to 47.6 micrograms per day — nearly 100 times higher than California’s Prop 65 limit.

This data shows that the average person is already consuming close to 100 times California’s Prop 65 threshold, regardless of protein powders — which, in fact, are not especially high in lead compared to many common foods. Yet, lead-related toxicological issues are not present in the average person.

What does this mean? It means this background exposure already exists in daily life. Lead is ubiquitous — present in soil, plumbing, dust, materials, and even in the air — and these sources alone expose us to quantities that far exceed Prop 65’s 0.5 µg/day warning level, no matter how carefully one tries to avoid it. The bottom line is that the Prop 65 recommendation is absurdly out of touch with real-world exposure. If the current lead consumption levels posed a major health concern, we would see widespread signs of lead toxicity across the general population — which we do not. 

Study 2:
Another study on actual lead consumption came from the EFSA Panel on Contaminants in the Food Chain (CONTAM), which gathered data from 14 EU Member States and Norway. Together, they submitted approximately 140,000 analytical results of lead in food and drinking water collected between 2003 and 2009.

Based on this extensive dataset, the panel reported that human lead exposure occurs mainly through food and water, with smaller contributions from air, dust, and soil. Among average adult consumers, lead dietary exposure ranged from 0.36 to 1.24 µg/kg body weight per day, with some cases reaching up to 2.43 µg/kg b.w. per day.

To put this in perspective, based on this data, a 70 kg person would already consume between 25.2 and 86.8 micrograms of lead per day — 50 to 174 times higher than California’s Prop 65 threshold of 0.5 micrograms.

A serving of Thrive Plant-Based Protein contains 3.1 micrograms according to a recent third-party testing certificate of analysis. Not only is plant-based protein safe, but most people naturally consume hundreds of times more lead each day through ordinary foods than what’s found in a single serving of it.

Research Clearly Shows Why Prop 65 Is So Misguided

Prop 65 may have been well-intentioned, but it's lead reccomendations have no basis in real-world exposure science — and it certainly shouldn’t serve as the backbone for speculative, sensationalized pieces like the one published by Consumer Reports.

Because Prop 65 treats any exposure above 0.5 µg/day as a significant hazard, it mandates warning labels on countless packaged products — yet raw foods like vegetables, which can naturally contain far higher lead levels, are exempt. This inconsistency highlights just how arbitrary and unscientific the regulation has become.

This kind of misrepresentation erodes public trust and makes genuine health risks harder to communicate. It has directly contributed to the misinterpretation and misinformation seen in the recent Consumer Reports article on plant-based proteins and heavy metals.

Lead Is Everywhere

Prop 65 asserts that no amount of lead exposure is safe. But in reality, there’s no such thing as lead-free food — lead exists naturally in virtually everything we eat.

Another important point to note is that not every governing body in the world sets a limit for lead. Take the U.S. FDA, for example. There are two likely reasons for this: first, because lead toxicity is not a widespread issue; and second, because anyone who spends 30 minutes reviewing the research on lead consumption levels can see that typical exposures are far beyond the Prop 65 value — making such a limit essentially pointless.

Section Summary

Hopefully you can now see that the Consumer Reports article demonstrates a clear lack of journalistic integrity and scientific rigour, and that Prop 65 has no place in our lives as consumers with regards to lead in food. It took me only a few minutes to locate multiple peer-reviewed research papers and regulatory assessments that directly contradict the Consumer Reports articles' claims — yet none of these were cited or even acknowledged. Whether this omission stems from bias, negligence, or an intent to sensationalize, the result is misinformation masquerading as consumer protection. Such reporting undermines public understanding of science and fuels unnecessary fear instead of promoting evidence-based discussion.

By now, I hope it’s clear that this recent media blow-up is nothing more than a misguided piece of fake news designed to scare consumers. I could go on with more peer-reviewed research, but for now, I’ll simply link them below for those who wish to read further. You can also do your own research by visiting Google Scholar and searching “lead levels in food.”

At the end of this analysis, I’ll go over several other major flaws in the Consumer Reports article.

6. How Much Lead Is Dangerous?

Is lead dangerous? Yes — lead is unquestionably a toxic metal and a known neurotoxin. At high levels of exposure, it can harm multiple organ systems, particularly the brain, kidneys, and cardiovascular system (WHO, 2019).

Lead absorption (bioavailability) in adults is predicted to be between 3–10% (ATSDR, 2020, p. 282). As stated earlier in this article, research demonstrates that the average person consumes around 70 µg of lead per day (140× the Prop 65 limit). When lead is consumed, it can be measured in the blood, and this is how toxicologists determine at what levels health issues occur—by the amount of lead present in the blood. In Canada, the average blood lead level in 2018–2019 was 0.82 µg/dL.

So what does 0.82 µg/dL of lead in the blood mean in relation to health effects? Toxicological research identified biological effects, such as kidney function changes, at 1.5 µg/dL, and the smallest detectable statistical change in cardiovascular function (a 1% rise in blood pressure) at 3.6 µg/dL (EFSA, 2010, p. 56–57). These values are 2–5 times higher than the average Canadian’s current level of 0.82 µg/dL. Furthermore, blood lead levels in Canadians are decreasing significantly each year (Health Canada, 2023).

The toxicology values cited above represent the earliest, most subtle identifiable health effects toxicologists could model, meaning that even if you did somehow start consuming 2–5 times more lead than you currently do, it would still likely have a negligible effect. For a more practical threshold, ATSDR (2020, p. 19) states: “At PbB <30 µg/dL, signs and symptoms of acute toxicity typically are not observed.” This means acute toxicological issues are not typically observed until 30 µg/dL of lead—36 times higher than the average Canadian’s blood lead level.

30 µg/dL, is however, very high and is an unsafe amount of lead if these levels persisted over time. The best source we have for how much lead is safe comes from the Centers for Disease Control and Prevention (CDC, 2024, July 10), who state the following values: 3.5 µg/dL as the current blood lead reference value for children (a screening level, not a toxicity threshold), and 10 µg/dL as the historical “level of concern” where minor adult health effects may begin to appear. Various toxicological research states different values for lead-related health effects, but all conclude that levels required are many times higher than the current blood lead levels in Canada of 0.82 µg/dL (EFSA, 2010; ATSDR, 2020; CDC, 2024).

In Canada, the average blood lead level is 0.82 µg/dL, a level that continues to decrease year over year (Health Canada, 2023). So, do you need to be worried about lead? Not unless you plan to consume around 12 times more lead than you currently do already (CDC, 2024). And do you need to be worried about rising lead levels in our foods? No, because lead levels are decreasing in the Canadian diet each year, with Canadians’ blood lead levels down 37% since 2009 (Health Canada, 2023). Furthermore, this is occurring despite a rise in the consumption of plant-based proteins by 2.4% each year (Agriculture and Agri-Food Canada, 2024).

Source: Health Canada, Lead in Canadians

7. Why Is Plant-Based Protein Being Targeted?

We must ask: why is plant-based protein under attack when many of the foods we eat every day naturally contain far higher levels of heavy metals and remain perfectly safe?

The first publication of this article even suggested that consumers switch to whey or yogurt, yet fails to disclose how the project was funded or whether any conflicts of interest exist. This lack of transparency further calls its objectivity into question. As a consumer, we must acknowledge that when one specific industry is attacked, there is reasonable probability that the motives and/or funding may come from a competitive sector.

Just bear in mind: lead is in soil, plants grow in soil, and plant protein is made from plants — therefore, it will naturally contain trace amounts of lead. But so does everything else you eat that grows in soil, or that eats things grown in soil. This narrow attack on plant-based protein is suspicious, especially given the article’s apparent bias toward promoting dairy.

8. Thinking Critically

It’s upsetting and frustrating for us as a business that one of our main products — which provides genuine health benefits — is being cast into doubt due to gross misinformation.

Remember: just because something is posted on the internet and includes the word “expert” doesn’t mean it’s true. Always look for sources, transparency, and data.

We encourage readers to think critically, do their own research, and rely on trusted scientific sources — not fear-based headlines.

9. Major Inaccurate Statements within the Consumer Reports Article

If you’re not already highly suspicious of the methods employed by the Consumer Reports “journalists,” I’ll now highlight several major scientific flaws within the article.

Inaccurate Statement 1:

This is a highly misinformed statement that contradicts a vast body of scientific literature supporting protein intake of 1.6–2.4 grams per kilogram of body mass per day for optimal recovery and adaptation in athletes. I have written extensively on this topic, citing peer-reviewed research rather than opinion, see here and here.

The “expert” quoted in the article is a chemist, offering an opinion outside their field of expertise and without any supporting research — not a conclusion grounded in sports nutrition or exercise physiology. It is misleading to present such commentary as scientific fact.

Be highly cautious of the word “expert” in vague, opinion-driven articles like this. I’m not claiming to be an expert — although I hold a First-Class Honours degree in Sport Science, that credential alone shouldn’t earn anyone’s trust. What should, however, is the use of actual scientific research, which is exactly what this article is based on.

Inaccurate Statement 2:

We’d like to point out that, statistically, the average American is overweight, sedentary, and consumes a calorie-dense diet far exceeding their energy needs. So yes — for that demographic, additional protein isn’t necessary. But let’s be honest: are you reading this as the average obese American, or as someone who trains, eats intentionally, and values recovery and performance?

For active individuals, the data overwhelmingly shows that optimal protein intake is far higher than population averages. It’s also worth asking — in a country like the U.S., where obesity, type II diabetes, and metabolic disease are at record highs — why target a product that supports muscle maintenance, improved body composition, and satiety?

If we’re going to scrutinize dietary risks, perhaps start with the well-documented issues in US food such as hormones, antibiotics, and contaminants present in conventional meat, dairy, and fish — not plant-based proteins that actually promote better health and environmental outcomes.

Inaccurate Statement 3:

Again, this statement is vague, oversimplified, and grossly misinformed. Government guidelines outline minimum intakes required to prevent deficiency — not levels that optimize health, recovery, or performance. These are survival thresholds, not performance targets.

To claim that “serious athletes” might find it useful to consume more protein is an embarrassingly weak summary of what decades of gold-standard research has clearly established. There is a large, peer-reviewed body of evidence demonstrating that protein intakes between  1.6 and 2.4 grams per kilogram of body weight per day are ideal for supporting muscle recovery, strength, and adaptation in athletes — not merely “useful.”

For readers interested in the actual science of protein intake, I’ve summarized the research and cited the primary studies in detail here in these articles (1 for muscle gain), (2 for endurance athletes). 

Inaccurate Statement 4:

Where is the data to support this claim? We've already established based on real research that lead levels in plant-based proteins are no higher than other foods we eat everyday, so where is this claim coming from? There is a wealth of research demonstrating the positive effects of supplementation on human health, yet to my knowledge, I’ve been unable to find any evidence suggesting that fortifying a diet poses a “greater risk.”

Inaccurate Statement 5:

The claim that Prop 65’s lead limit “has a wide safety margin built in” is highly misleading. The Prop 65 MADL of 0.5 µg/day was not derived from dietary exposure data or toxicological thresholds—it is a legal warning level, not a scientifically established safety limit. In fact, the “wide safety margin” used for Prop 65 is 1,000× lower than the level of exposure associated with any observed harm in the toxicological research it was based on. Typical safety margins in toxicology are 50× or 100×, not 1,000×. Applying such an extreme buffer produces a value that has no relevance in a real-world dietary context.

Numerous dietary exposure assessments show that the average adult already consumes roughly 140 times this amount of lead each day through common foods such as vegetables, grains, and water. This is consistently supported by a broad body of peer-reviewed research documenting daily intakes hundreds of times higher than the Prop 65 limit.

The fact that Prop 65’s threshold is 20 times lower than Health Canada’s already stringent daily limit does not make it “safer” or “more protective”—it makes it scientifically inappropriate as a reference for evaluating food safety.

Misrepresentation of Expertise
Consumer Reports frequently cites “experts” who offer overly simplified statements on complex scientific issues, creating the illusion of authority while omitting critical nuance, context, or any supporting materials. 

For instance, is an “expert” who “oversees food safety research and testing at Consumer Reports” truly more qualified to define safe lead levels than the extensive body of peer-reviewed toxicological literature showing no adverse effects at far higher levels? Invoking a PhD title to legitimize statements that contradict decades of evidence is an appeal to authority, not science.

Using credentials in this way to bolster weak or misleading claims undermines scientific integrity and public trust. Oversimplifying nuanced research for headlines or advocacy erodes confidence in legitimate science communication—and in this case, it reflects a troubling lapse in editorial and scientific standards.

Inaccurate Statement 6:

This statement implies that lead in foods is a new emerging issue - this simply is not true.

Lead levels in Canadians has dropped 37% since 2009 (Health Canada, 2023).

The statement that “there were also fewer products with undetectable amounts of lead” is also a major red flag. There will virtually never be protein products with completely undetectable levels of lead, because lead is naturally present in all soil and therefore detectable in all agricultural produce and plant-based proteins.

Inaccurate Statement 7:

This claim may go unnoticed by many, but it is in fact highly unlikely. Most supplement manufacturers produce batches that last several months per batch, not just a few weeks. A standard production run for a popular product can easily generate enough inventory to supply one to three quarters—and in some cases, up to two years—of stock, depending on demand and distribution scale.

Basic inventory management practices dictate that new batches are not released until previous inventory is sold through. As such, there is no realistic scenario in which four distinct production lots of the same product would be available for purchase simultaneously.

Furthermore, the product in question has a two-year shelf life, leaving no operational justification for four separate production runs within a three-month period. Producing new batches that frequently would be both economically inefficient and logistically unnecessary.

In short, the claim that four independent production lots were purchased within such a short timeframe is implausible and reflects a fundamental misunderstanding of commercial manufacturing, batch coding, and inventory turnover. It is far more likely that the samples were drawn from the same production lot, even if purchased on different dates.

To some, this may seem pedantic, but it matters — because once again, this article demonstrates a complete lack of integrity or scientific rigour. They’re not engaging in proper review or verification; they’re simply making statements and hoping readers accept them at face value. That’s not journalism, and it’s certainly not science.

Thrive Protein’s Commitment to Quality and Transparency

At Thrive Protein, we take product safety and ingredient integrity seriously. All of our products — including our Plant-Based Protein, Whey Protein Isolate, and other formulas — are:

• Third-party tested before release
• Produced in Health Canada–licensed, GMP-certified, and CFIA-inspected facilities
• Verified to be well below Health Canada’s heavy metal thresholds

For example, our most recent batch of plant-based protein contained 0.098 ppm of lead, more than 2.5 times below Health Canada's limit of 0.249 ppm. Every batch has a Certificate of Analysis (COA) available upon request, and we are in the process of making these results publicly accessible on our website. Here is our most recent vanilla plant-based protein COA. 

If a product fails to meet testing standards, it is destroyed and never sold. Fortunately, this has never happened, thanks to the high-quality ingredients we source and the rigorous standards we uphold.

We believe in the utmost quality of our ingredients and have specifically partnered with manufacturers who share our values and commitment to high standards — including Good Manufacturing Practice (GMP) certification, Health Canada–licensed facilities, CFIA inspections, and third-party testing prior to release.

An independent third party, unrelated to both us and the manufacturer, takes a sample from every single lot of every single variant in our product line to test for various contaminants, including heavy metals. There are strict specifications for each potential contaminant that must be met to pass these third-party testing standards.

To be clear, none of our protein powders come remotely close to Health Canada’s thresholds when tested for heavy metals. 

About the Author:

Joe is a certified personal trainer, strength and conditioning coach, and nutrition coach. He holds a Bachelor of Science with Honours in Sport and Exercise Science, graduating with First Class standing. During his studies, Joe focused on human physiology and performance, and he applies this knowledge of exercise science to his work with Thrive. He is the co-founder of Thrive Protein, a Canadian family-run supplement company focused on clean, scientifically backed nutrition products — including protein powders, greens, and electrolytes.

Appendix:

The exact Prop 65 method with supporting documentation

I'm including this here for those of you who wish to fact check Prop 65, if not interested, move onto the next section.

Finding the exact reasoning for Prop 65’s methods was not easy; however, this information is documented in Office of Environmental Health Hazard Assessment (OEHHA) June 1989 Final Statement of Reasons for the lead “safe harbor” level under Proposition 65 (OEHHA, 1989, pp. 77–79).  Voters approved the concept of Proposition 65, but all the actual numbers — including the 0.5 µg/day for lead — were later determined by bureaucrats and scientists at OEHHA, not by the public.

Here’s the official derivation: OEHHA’s predecessor took OSHA’s lead permissible exposure limit (PEL) of 50 µg/m³, assumed an 8-hour inhalation of approximately 10 m³ (≈500 µg/day), and then applied Prop 65’s 1,000× safety factor to set the reproductive MADL at 0.5 µg/day. This calculation appears on page 77 of the Final Statement of Reasons.

In the original 1989 document, OEHHA responded to public criticism that the 0.5 µg/day threshold was impossibly strict. Commenters argued that the value was unrealistic and that few businesses could meet it, but the agency replied that its purpose was not to ensure feasibility or compliance—only to set a level that could be regarded as unquestionably safe “within the meaning of the Act.” It added that businesses could still defend higher exposures by proving no observable effect in enforcement actions. In 2018, an appeal was made in Mateel Environmental Justice Foundation v. OEHHA (2018), an appeal that challenged how impractically low the Prop 65 threshold is. Although unfortunately, Prop 65 was not overturned, likely not because its science was strong, but because the judge’s job was to review procedure, not redo the science — and by that narrow legal standard, OEHHA’s record passed and Prop 65 remains.

This is striking because OEHHA explicitly acknowledged that the limit was set without regard for practicality or achievability—they prioritized an absolute margin of theoretical safety (1,000× below occupational exposure) even if “many cannot comply.” So simply, Prop 65 won the case because they claimed, this is a level we can guarantee with certainty has no effect on human health, not a level that should be used as a threshold for safety.

References:

Agency for Toxic Substances and Disease Registry (ATSDR). (2020) Toxicological profile for lead. U.S. Department of Health and Human Services. Available at: https://www.atsdr.cdc.gov/ToxProfiles/tp13.pdf

Agriculture and Agri-Food Canada (AAFC). (2024) Sector Trend Analysis – Plant-based Protein Food and Drink Trends in Canada. Government of Canada. Available at: https://agriculture.canada.ca/en/international-trade/market-intelligence/reports-and-guides/sector-trend-analysis-plant-based-protein-food-and-drink-trends-canada

California Office of Environmental Health Hazard Assessment (OEHHA). (1989) Final Statement of Reasons for the Reproductive and Cancer Hazard Identification Committee (Lead Safe Harbor Level). California Environmental Protection Agency.

California Office of Environmental Health Hazard Assessment (OEHHA). (n.d.) Lead and Lead Compounds — Proposition 65 Maximum Allowable Dose Level (MADL). Available at: https://oehha.ca.gov/proposition-65/chemicals/lead

Canadian Agri-Food Policy Institute (CAPI). (2023) Canada’s Fruit and Vegetable Import Reliance Report. Available at: https://capi-icpa.ca

Centers for Disease Control and Prevention (CDC). (2024, July 10) Blood Lead Reference Value (BLRV) for Children. National Institute for Occupational Safety and Health (NIOSH). Available at: https://www.cdc.gov/niosh/lead/bll-reference/index.html

Codex Alimentarius / FAO–WHO. (1995) General Standard for Contaminants and Toxins in Food and Feed (CXS 193-1995). FAO/WHO.

European Chemicals Agency (ECHA). (n.d.) Lead – Hot topic. Available at: https://echa.europa.eu/hot-topics/lead

European Food Safety Authority (EFSA). (2010) Scientific Opinion on Lead in Food. EFSA Journal, 8(4), 1570. doi: 10.2903/j.efsa.2010.1570

European Union. (2006) Regulation (EC) No. 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs: Annex. Available at: https://www.legislation.gov.uk/eur/2006/1881/annex

Health Canada. (2023, December 21) Lead in Canadians: Findings from the Canadian Health Measures Survey. Government of Canada. Available at: https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/environmental-contaminants/human-biomonitoring-resources/lead-canadians.html

Health Canada. (n.d.) Quality of Natural Health Products: Guidance Document. Government of Canada. Available at: https://www.canada.ca/en/health-canada/services/drugs-health-products/natural-non-prescription/legislation-guidelines/guidance-documents/quality-guide.html

Liu, P., Wang, C.-N., Song, X.-Y. and Wu, Y.-N. (2010) ‘Dietary intake of lead and cadmium by children and adults – Result calculated from dietary recall and available lead/cadmium level in food in comparison to result from food duplicate diet method’, International Journal of Hygiene & Environmental Health, 213(6), pp. 450–457. doi: 10.1016/j.ijheh.2010.07.002

Mateel Environmental Justice Foundation v. Office of Environmental Health Hazard Assessment. (2018) Court of Appeal of California, First Appellate District, Division One, Case No. A149970.

Moon, C.-S., Paik, J.-M., Choi, C.-S., Kim, D.-H. and Ikeda, M. (2003) ‘Lead and cadmium levels in daily foods, blood and urine in children and their mothers in Korea’, International Archives of Occupational and Environmental Health, 76, pp. 282–288. doi: 10.1007/s00420-002-0372-z

Sanders, T., Liu, Y., Buchner, V. and Tchounwou, P. B. (2009) ‘Neurotoxic effects and biomarkers of lead exposure: A review’, Reviews on Environmental Health, 24(1), pp. 15–45. doi: 10.1515/REVEH.2009.24.1.15

Schrey, P., Wittsiepe, J., Budde, U. et al. (2012) ‘Human exposure to lead via food – a total diet study for the German population based on the NVS II dietary survey’, Food Additives & Contaminants: Part A, 29(8), pp. 1320–1330.

United States Department of Agriculture (USDA) Economic Research Service. (2023) Fruit and Vegetable Imports Share. USDA ERS. Available at: https://www.ers.usda.gov

United States Food and Drug Administration (FDA). (2020) Total Diet Study: FY2018–FY2020 Analytical Results. U.S. Food and Drug Administration. Available at: https://www.fda.gov/food/total-diet-study

UK Health Security Agency. (2024, October 8) Lead poisoning: advice for the public and healthcare professionals – Lead: information for the public. GOV.UK. Available at: https://www.gov.uk/government/publications/lead-poisoning-advice-for-the-public-and-healthcare-professionals/lead-information-for-the-public

UK Health Security Agency. (2024, October 31) Lead: toxicological overview. GOV.UK. Available at: https://www.gov.uk/government/publications/lead-properties-incident-management-and-toxicology/lead-toxicological-overview

World Health Organization (WHO). (2019) Lead poisoning and health. WHO Fact Sheet. Available at: https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health