Protein Powder and Food Allergy: Milk, Soy, Egg, Peanut and Tree-Nut Cross-Contact and Emergency Signs

Emergency signs first

A serious allergic reaction (anaphylaxis) can begin very quickly and symptoms may be life-threatening. [1] MedlinePlus lists signs across the body: itching, hives and swelling of skin; itching or swelling of the mouth, lips or tongue; throat tightness, trouble swallowing; shortness of breath, wheezing; a weak pulse or passing out; vomiting and cramps; dizziness or fainting. [1]

If someone is having a serious allergic reaction, call 911 (US). [1] If the person has been prescribed an adrenaline (epinephrine) auto-injector, the NHS says to use it immediately, and to call for an ambulance afterward even if they seem better. [2] In the UK the NHS number is 999. [3] The NHS adds that anaphylaxis needs to be treated in hospital immediately. [3] The FDA lists milder signs too, such as hives, tingling in the mouth, face or lip swelling, vomiting, diarrhea and cramps, and says to stop eating the food and seek medical attention. [4] The FDA says symptoms typically appear from within a few minutes to a few hours after eating. [4]

This page is information, not a diagnosis. If you think you or your child may have a food allergy, see a clinician; the NHS notes you may be referred to a specialist for tests. [2]

Why protein powders raise allergy questions

Food allergy is the immune system overreacting to certain foods. [2] Many protein powders are made from foods on common allergen lists. The NHS names cows' milk, eggs, peanuts, soybeans, peas and chickpeas, tree nuts, shellfish and wheat among the most common allergic foods. [2]

See the product pages for whey, casein, plant powders, soy protein, egg-white and other powders and milk protein, lactose and dairy allergy.

What US labels must show

The FDA says the major food allergens are milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame. [4] The source of the allergen must appear in parentheses after the ingredient name or in a "Contains" statement next to the ingredient list. [4] The FDA's allergen guidance covers dietary supplement products among other items. [4] Check each tub, bar and drink; formulas change. See Reading a protein powder label and Reading supplement labels.

Cross-contact and "may contain" statements

Cross-contact is the inadvertent introduction of a major allergen into a product. [4] Statements such as "may contain" or "produced in a facility that also uses" are advisory. The FDA says they are not required by law, are meant for unavoidable cross-contact, and are not a substitute for good manufacturing practices. [4] The FDA also says that, at this time, it has not established a threshold level for any allergens. [4]

What does that mean in practice? A UK study of products with and without precautionary allergen labeling found that most products testing positive for an allergen contained a concentration predicted to cause a reaction in more than 1% of the allergic population, in products both with and without such labeling. [5] Those were general UK foods, not protein powders, so they are an illustration and not a measurement of powders. Our reading: a missing advisory statement is not proof that a product is free of an allergen, and an advisory statement is not a guarantee either. Ask an allergist how to interpret labels for your situation.

The FDA says milk is the most common cause of recalls due to undeclared allergens among the major allergens. [4]

Case report: a reaction in someone who tolerated milk

A published case report describes anaphylaxis after a whey sport supplement shake in a patient described as cow's-milk tolerant. [6] We could not read the abstract, so we cannot say more about the details. Single case reports do not show how common this is.

Hydrolyzed and isolate products

Whether whey isolate or hydrolysate powders are safe for people with milk allergy: Proper evidence not found in the sources we read for adults (we searched PubMed for whey supplement anaphylaxis and hydrolyzed whey allergy and found infant formula and animal studies, not adult powder safety data). Do not assume "isolate" or "hydrolyzed" means allergen-free.

Milk allergy versus lactose intolerance

They are different. Lactose is a sugar found in milk and dairy products, and lactose intolerance happens when the small intestine does not make enough of the enzyme needed to digest it. [7] MedlinePlus says it is very common in adults and rarely dangerous. [7] The NHS explains that a food intolerance causes symptoms such as bloating and tummy pain, unlike an allergy. [2] A lactose-free label does not mean milk-protein-free.

Reporting

The FDA says a person with symptoms should contact their health care provider, and gives a route to report a complaint or adverse event to the agency. [4] More: Side effects, allergic reactions and reporting.