Key takeaways:
- Uncertainty exists about the impact of trace heavy metals in plant-based protein powders, with a lot of concern fueled by reports from Consumer Reports and The Clean Label Project.
- Despite concerns, the heavy metal levels in average vegan protein powders are comparable to those in normal foods, suggesting no increased risk with consumption of protein shakes as long as you’re not drinking many a day.
- Still, if you’d like to minimize heavy metal intake, opt for non-organic pea protein powders sourced from well-regulated and known for having lower levels of heavy metals in soil (like Europe instead of China).
There’s a lot of confusion about whether or not trace amounts of heavy metals in plant based protein powders are a big deal or not.
I’ll clear that up for you.
By the end of this post you’ll know:
- What level of heavy metals are in vegan protein powders
- How the heavy metals in protein powders compare to heavy metals in normal food
- If you should cut back or eliminate protein powder from your diet
- Which protein powders to stick to if you’d like to limit your heavy metal intake
Table of Contents
Why Are There Heavy Metals in Vegan Protein Powder?
There are 2 main reports that have led to the confusion on this topic:
- A 2010 Consumer Report test of 15 whey protein powder and weight gainers found that all of them had detectable levels of heavy metals in them (1). We won’t worry about this too much since it was a small sample, and only looked at non-vegan protein powders (milk is known to have high levels of arsenic (2)).
- The Clean Label Project tested over 100 popular protein powders off the shelf and found detectable levels of BPA, lead, and other heavy metals (3). However, specific brands were not identified.
Is The Clean Label Project Reliable?
The Clean Label Project is a non-profit that tests food items for heavy metal content and reports on them.
However, despite a few sensationalist articles that were written after the report was released, there are some big limitations:
- It’s a single report
- There was no peer review or third party data verification
- There was no comparison to the heavy metal content of whole foods
- While some data was released, there wasn’t full transparency (i.e. complete data along with brand names)
The Clean Label Project also seems to rely on affiliate income (from products they give their “certification” to) and donations to subsist. There’s nothing wrong with that by itself, but it does potentially give an incentive to exaggerate the severity of heavy metals (and make their work seem more necessary).
A 2020 peer reviewed study was published in the Toxicology Reports journal, which assessed the data from the reports above (4). I’ll be relying on and summarizing it throughout the rest of this post. But if you want the final conclusion:
The data in the current study suggest that heavy metal exposure via protein powder supplement ingestion does not pose an increased non-carcinogenic risk to human health.
The reports by The Clean Label Project and Consumer Reports do warrant further investigation on the presence of heavy metals in plant based protein powders. However, they are not sufficient by themselves as a reason to not consume protein powder at this time.
What Are the Health Risks of Heavy Metal Consumption?
There’s no doubt that heavy metals are not good for health.
However, heavy metals are naturally found in Earth’s crust, so there’s trace amounts in most soil.
It’s not surprising that a small amount of heavy metals isn’t likely to cause health problems, it’s just when we have repeated exposure to high doses. Unfortunately, heavy metals are used in agriculture, industrial, medical, and other settings and often end up adding more to the environment, which ends up in soil and food (5).
There are 4 heavy metals in particular that were identified by those 2 earlier reports.
| Heavy Metal | About | Dangers |
|---|---|---|
| Arsenic | Arsenic naturally occurs in ash, ore, groundwater, food, soil, and even air (6). | As a group 1 carcinogen, arsenic is known to increase the risk of cancer if exposure is high enough. |
| Cadmium | Cadmium is found in the Earth’s crust, but relatively rare compared to other elements. Certain fertilizers contain concentrated amounts of cadmium, as well as coal. It is easily absorbed by ground crops like rice. | Too much cadmium exposure is associated with several serious illnesses including: kidney disease, hypertension, cardiovascular disease, cancer, CNS toxicity, and more (7). |
| Lead | Lead can easily be absorbed by plants if released into the environment. | Lead toxicity can lead to a wide variety of reproductive, respiratory, neurological effects, cancer, and more (8). |
| Mercury | Most mercury comes from coal-fired power plants. Some also comes from oil combustion, gold production, and other smaller sources. It does not decompose easily, and accumulates in animals in the ecosystem, particularly fish (large fish are known to accumulate high levels of mercury). | Mercury can cause a wide variety of disorders including: neurological, nephrological, immunological, cardiac, motor, reproductive, and genetic disorders (9). |
Clearly heavy metals are serious health threats that shouldn’t be taken lightly. They can accumulate in the body and can’t be filtered out efficiently.
That’s why even though those reports we looked at weren’t conclusive by themselves, you should still keep an open mind if further studies on this topic find more concrete results.
All people consume some level of heavy metals, they’re in just about everything. However, it’s smart to be aware of which food products you eat are high in heavy metals and try to limit your consumption to safe amounts.
Do Plant Based Protein Powders Have More Heavy Metals Than Whey?
Even though some dairy is known for having high levels of heavy metals like arsenic, plant protein powders do typically have higher levels of heavy metals than whey or casein protein (4). This is mainly due to crops like peas and rice absorbing heavy metals from the surrounding soil.
Are Heavy Metals in Plant-Based Protein Powder Dangerous?
Now comes the most important question: even if there are heavy metals in protein powder, are they a high enough concentration to be dangerous?
This is the main context that was missing from nearly every article that I saw written based on the earlier reports we touched upon.
The recommended upper limits of heavy metals varies based on organization. I found the clearest ones I could find, and created the table below for comparison:
| Recommended Acceptable Daily Limit (10) | Clean Label Project Median Per Serving (mcg) | Average Daily Intake for EU Adult (mcg) (11) | Main Dietary Sources | |
|---|---|---|---|---|
| Arsenic | 10 | 0.55 | 120* (25 excluding fish) |
|
| Cadmium | 6 | 1.44 | 14.4 |
|
| Lead | 20 | 0.08 | 42 |
|
| Mercury | 40 (12) | 0.61 | 5.53 |
|
Compared to a typical diet or the recommended upper limit, the amount of heavy metals in the median protein powder is fairly insignificant.
However, some brands could be significantly worse depending on where ingredients were sourced.
The biggest concern for protein powder is the cadmium content. If you had 3 servings of a protein shake per day, you get close to the recommended limit, which most people already go over. Again, some other organizations set the recommended cadmium limit higher, so you don’t necessarily need to panic.
The amount of heavy metals in the average protein powder is comparable to normal food. Having 2-3 shakes a day should not put someone at any increased risk compared to getting that protein from whole foods.
Do Some Vegan Protein Powders Have Fewer Heavy Metals Than Others?
There are 2 main ways that you can limit your exposure to heavy metals while consuming vegan protein powder.
First, if you have trust in the Clean Label Project’s data, they found that organic protein powders have a higher level of heavy metals than non-organic products (3):
However, note that it says “up to 1.5x more”. That doesn’t mean that all organic protein powder has higher levels of heavy metals, it will vary by brand.
Secondly, while more concrete data would be nice, it does appear that pea protein will generally have lower heavy metal content than brown rice protein. These are the 2 most popular vegan protein powders, which is why you should specifically consider them.
Quite a bit of research has shown that rice absorbs heavy metals readily from the soil, so if it’s grown in a region with poor environmental regulation, the rice is more likely to be contaminated.
For example, a study of rice from an area near a typical E-waste recycling area in southeast China found high levels of heavy metals (13).
There are vegan protein powder brands like Nuzest and Future Kind that source their pea protein from North America and Europe, that seem more likely to be lower in heavy metals (again, just speculation, I don’t have data to back that up).
Finally, some protein powder manufacturers get their powder tested by third parties for heavy metal content, which can give you extra confidence in the product.
To minimize heavy metal intake from vegan protein powders, stick to non-organic powders that are mostly made from pea protein. If the ingredients are sourced from more regulated countries and tested by third parties, even better.
Is Prop 65 a Good Solution?
One thing you’ll see on a ton of products (aside from protein powder) is a Prop 65 heavy metal warning.
California makes manufacturers put this on their product labels for certain food products if they exceed a certain threshold for heavy metals. It sounds good in practice, but the levels are incredibly strict, so very few products can meet it. For example, one serving of most fruits exceeds the limits.
Currently, you’ll find this warning on almost every protein powder and supplement label, and most people don’t pay it too much attention. Good idea, but not the best execution.
If you see a Prop 65 warning on a vegan protein powder, I wouldn’t be worried about it.
Summary: Heavy Metals in Vegan Protein Powder
Currently, there is some data that shows there could be dangerous levels of heavy metals in certain protein products.
However, there are serious limitations to this data, and once it’s compared to the levels of heavy metals in other food, it’s clear that most vegan protein powders have a safe level of heavy metals in them. Even 3 servings a day isn’t likely to be any more dangerous than eating more protein from common vegan protein sources.
This is a reasonable concern to have, and I really hope we do see more peer-reviewed research on heavy metals in plant-based protein powders. More data would help us have more confidence in the safety of these products, one way or another.
Are There Any Other Dangers Of Drinking Vegan Protein Shakes?
There aren’t too many other concerns besides heavy metals.
Some research has also shown that too much protein can cause liver damage long term. As long as you’re not chugging down 5+ shakes a day, that shouldn’t be an issue, but it’s another thing to consider.
In addition, almost all vegan protein powders contain some sort of sweetener. The most common ones by far are Stevia and sugar.
Stevia is possibly the most heavily studied natural sweetener,and all evidence points to it being safe to consume.
Whether or not it’s healthy and helpful for losing weight is another topic altogether with a less clear answer.
References
- https://www.consumerreports.org/media-room/press-releases/2010/06/investigation-tests-reveal-contaminants-in-many-protein-drinks/
- https://link.springer.com/article/10.1007/s00244-012-9810-3
- https://cleanlabelproject.org/protein-powder-infographic/
- https://www.sciencedirect.com/science/article/pii/S2214750020303632
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4144270/
- https://www.atsdr.cdc.gov/HEC/CSEM/arsenic/docs/arsenic.pdf
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5596182/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4961898/
- https://www.sciencedirect.com/science/article/pii/S1382668905000700
- https://www.nature.com/articles/s41598-020-76000-w
- https://ec.europa.eu/food/system/files/2016-10/cs_contaminants_catalogue_scoop_3-2-11_heavy_metals_report_en.pdf
- http://mercuryfactsandfish.org/mercury-facts/the-safe-or-reference-dose/
- https://www.sciencedirect.com/science/article/abs/pii/S0045653507015317
