Protein Powder Safety: Allergens, Lactose, Added Ingredients, Contaminants and Kidney Disease

Urgent first

A serious allergic reaction can be life threatening. [1] The NHS says to call 999 (UK) if your lips, mouth, throat or tongue suddenly become swollen, and lists other warning signs on its page. [2] In the US, call 911. If you have a prescribed adrenaline auto-injector, the NHS says to use it immediately, and to call 999 for an ambulance after using it even if you feel better. [2] Do not drive yourself to hospital. [2]

Overview

Protein powders are dietary supplements. In the US, FDA can act against an adulterated or misbranded supplement only after it reaches the market, and is not authorized to review supplements for safety and effectiveness before sale. [3][4] This page covers the practical risks: allergens, lactose, added ingredients, contaminants and kidney disease. It complements Reading Supplement Labels and Product Quality and Contamination.

Allergens

The NHS lists cows' milk, eggs, soybeans and peas among the most common allergic foods. [2] In the US the major food allergens are milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame. [5] Whey and casein are milk proteins, and egg-white, soy and pea powders are made from allergenic foods, so each can matter for someone allergic to the source. The NHS advises people with a food allergy to check labels carefully and not to eat foods without checking ingredients. [2] Hydrolyzed whey is partly broken down to reduce allergenicity, and a review notes a trade-off with bitterness. [6] The sources read for this page do not show it is safe for milk allergy, so ask an allergy specialist.

Lactose is not allergy

Lactose intolerance is a digestive condition and differs from milk allergy, which is an immune system disorder. [7] Many people with lactose intolerance can take some lactose without symptoms. [7] The NHS lists diet and protein shakes among processed foods that can contain lactose, and says a lactase supplement may help some people. [1] Whey concentrate keeps some fat and lactose; isolate is about 90 percent protein. [6]

Added ingredients

Some products marketed for bodybuilding may contain prescription drugs not allowed in supplements or ingredients not on the label. [4] Many "high protein" products carry added sugars and fats and more calories. [8] Check sweeteners, flavors and any extra herbal or stimulant ingredients, and see Amounts and Duplicate Ingredients.

Contaminants

Study results are mixed and limited. A 2021 Irish study analyzed 36 protein powders on sale in 2016 and 2017 for 21 elements and found potentially toxic elements at acceptable levels, but its risk assessment suggested that excessive, prolonged use of some products could slightly raise lifetime health risk, and it advised following serving recommendations. [9] One country, one period; it cannot be applied to every product. For athletes, a review of 23 studies found banned substances in most supplements it analyzed, with contamination rates between 12 and 58 percent depending on the study. [10] See Sports Certification and Banned-Substance Contamination.

Kidney disease and high protein

Some people with chronic kidney disease may need to eat only moderate amounts of protein, and too little can cause malnutrition, so the balance should be set with a dietitian or health professional. [11] Older people with severe kidney disease (eGFR below 30, not on dialysis) may need to limit protein. [12] In healthy adults without kidney disease, a meta-analysis found higher-protein diets did not adversely influence kidney function, though the trials had unclear risk of selection bias. [13] A systematic review of 11 papers linked harmful effects mainly to chronic, heavy whey use, with kidney and liver most often named. [14] Do not treat the lack of harm in trials as proof of safety for long-term heavy use.

Who should ask first

Many supplements have not been tested in pregnant women, nursing mothers or children. [4] Children and teens may need different protein amounts from adults. [15] See Pregnancy and Breastfeeding, Children and Teens, Existing Conditions and How Interactions Work.

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