By Selina Lai, MS, Nutritionist
In the past year there have been 2 investigative surveys of the lead content of protein powder supplements published by The Clean Label Project1 and more recently by Consumer Reports2,3. The resulting analysis of protein powder supplements provided some alarming findings of elevated levels of lead, particularly in plant-based protein powders. Why would plant-based protein supplements have dramatically higher content of lead when compared to animal-based protein supplements? Lead is a naturally occurring element in our environment, absorbed from the soil wherever a crop is grown. There is potential for contamination during manufacturing or farming practices (consider fields near roads or industry) and plant proteins have less protein content per volume when compared to dairy or animal sources. Thus, during the manufacturing process they are highly concentrated.
The Food and Drug Administration provides an Interim Reference Level (IRL) for lead that serves as a benchmark for daily lead intake, 2.2 μg/day for children and 8.8 μg/day for females of childbearing age, to protect against adverse health effects, particularly neurological impacts in children4. The IRL for lead allows for a 10x safety factor for exposure. The most stringent daily lead exposure guideline is the Maximum Allowable Daily Limit (MADL)5, 0.5 μg/day, from California Proposition 65, which is extremely restrictive when compared to the FDA IRL for lead. The Consumer Reports research used this very strict California Prop 65 guideline to evaluate the protein powders, which adds additional protection to consumers, but it may actually be overstating the risk to typical protein powder users. That being said, consuming goods that minimize lead levels is a healthy practice because there is naturally occurring lead in most of the food we eat.
The “Better Nutrition for FSHD” diet6 recommends the consumption of a minimum of 1.2g protein/kg of body weight. This recommendation is based on research of dietary intake in muscular dystrophy patients7, dietary needs of elderly people with sarcopenia8, the USDA dietary recommendations for athletes, seniors and at-risk populations9. This level of protein intake is recommended with the caveat that 2-3 meals are consumed daily that contain 25-30 grams of protein and 2.5 to 2.8 grams of the amino acid leucine, to stimulate skeletal muscle enzyme pathways that activate skeletal muscle growth. Studies have shown that in senior citizens with limited physical activity, consuming this recommended level of leucine at each meal maintained muscle mass and strength. For FSHD patients who exercise regularly, consuming a recovery meal that includes this recommended level of protein and leucine should help with repairing muscle damaged during the normal course of physical activity. The “Grocery List for FSHD”10 offers a wide range of nutritious, high quality protein foods choices to include to meet protein intake goals.
The “Better Nutrition for FSHD” diet also recognizes that FSHD patients often have fatigue from activities of daily living and offers ideas to simplify consuming a healthy diet. The inclusion of a protein shake can be a useful healthy option for FSHD patients. Whey protein isolate is the most concentrated source of high-quality, high-absorption protein supplement. Whey protein comes from dairy foods – milk, yogurt, cottage cheese, eggs. Leucine, the amino acid responsible for activating skeletal muscle synthesis, makes up approximately 10% of the amino acids in whey. Other milk proteins, such as casein, also contain high amounts of leucine, and naturally have a slower absorption in the gut, extending the benefits of leucine’s anabolic effect. Furthermore, protein shakes can provide a wealth of nutrition when consumed with added elements such as fresh or frozen fruit, chia seeds or hemp hearts, purple corn powder, nuts of choice, or a few leafy greens.
The analysis from these 2 surveys of lead content in protein powders can help FSHD patients make an informed choice about which protein powder to include in a diet. Most of the plant-based protein powders tested had levels of lead that exceeded Proposition 65’s Maximum Allowable Daily Limit per serving. In general, whey protein products had the least amount of lead in the tested products. The Clean Label Project has created a “Clean 16” protein powder recommendation list based on their analysis11. The list also considers other heavy metals that were analyzed – cadmium (chocolate products generally have higher amounts) and arsenic. The Consumer Reports article also provides consumption guidance for the protein powder products they analyzed.
Another high-quality vegan protein option that is becoming more available in the marketplace is vegan whey protein food products. Strive Freemilk is an animal-free dairy milk made with a microbe-produced whey protein12. It is a highly sustainable and animal-free milk option.
Presently, there is a clinical trial happening at McGill University in Montreal, Quebec to further determine the protein requirements of FSHD patients. Arianne Zabbal, a MSc student at McGill in the Department of Kinesiology and Physical Education, is the researcher leading the study under the supervision of Dr. Tyler Churchward-Venne. I was fortunate enough to interview Ms. Zabbal about the project this week. Her study uses a relatively new method of determining protein requirements, Indicator Amino Acid Oxidation -IAAO, which measures the oxidation levels produced when consuming known dosages of protein in the diet (grams of protein per kilogram body weight) using a carbon-labelled amino acid. After an initial assessment visit, study participants visit the kinesiology lab for seven sessions where they receive a randomized dosage of an egg-based protein, with carbon-labelled phenylalanine, and then, over eight hours, there is a collection of urine and breath analysis to measure the oxidation of this amino acid. “When you have lower doses (of protein) you’re going to have a lot more (amino acid oxidation) coming out in your breath and in your urine…until you get to a dose we call the ‘break point’. That’s when your body has exactly enough (protein) to maximally stimulate protein synthesis or at least put yourself in a stage where that’s possible. That’s called the Estimated Average Requirement or the EAR.”, states Zabbal. At the break point amino acid oxidation is minimal because adequate protein for metabolism is being provided via the diet.
So far eight FSHD patients have participated in the study and Zabbal is hoping to get a total of ten. Her biggest challenge in the study was recruiting patients. With the help of Dr. Erin Ferrall, Zabbal learned about FSHD and connected with a few patients in Montreal. Then she reached out through FSHD Facebook groups and found the FSHD Society. “I don’t think I was expecting the amount of positivity from the community that I got.” In August 2025, the Quebec Chapter of the FSHD Society had their inaugural meeting and Zabbal was invited to share her research study with the enthusiastic FSHD patients of Quebec. Patients have come from Quebec, Ontario and even the US to participate. Zabbal noted that the FSHD patients have been knowledgeable about nutrition and understand the importance of her research project. “It felt like I was kind of talking to like a colleague almost because they knew what they were talking about.”, said Zabbal.
Zabbal is aiming to present her study findings at the 2027 FSHD International Research Congress.
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