Milk proteins

Studies in people

• Benefit

  Muscle building after eating⁵

  Milk protein and corn protein both boosted muscle building in young men, with no difference between them.

• Open question

  Infant immune response to food⁸

  Babies briefly fed hydrolyzed formula had lower levels of some milk protein antibodies than those fed regular formula.

• Concern

  Feeding problems in preterm babies⁹

  In preterm babies, milk proteins sometimes caused feeding problems that eased once feeds were changed.

• No harm found

  Vitamin D levels compared¹⁰

  Infants with cow's milk protein allergy did not have different vitamin D levels than healthy infants.

Animal and lab studies only

• Open question

  Gut cell effects¹¹

  In lab studies, milk proteins clumped with lactoferrin and did not change how lactoferrin worked in gut cells.

Allergies and intolerances

These are about people with an allergy, an intolerance or coeliac disease. The signal is about the ingredient itself, and these are about the person eating it, so the signal does not count them.

• Outgrowing food allergy²

  Milk proteins can cause allergic reactions in young children, and scientists are studying ways to help them outgrow it.

• Allergy in young children³

  Cow milk is the most common cause of food allergy and intolerance in young children, and the two are often confused.

• Infant infection risk⁴

  Babies with cow's milk protein allergy had more infections, antibiotic use, and hospital stays than babies without it.

• Allergy in babies⁷

  Experts agree milk proteins can cause allergy in babies, and special formulas help, but diagnosis needs care.

• Gut polyp immune response¹²

  In lab studies, immune cells from gut polyps of milk-protein-allergic patients reacted to milk proteins.

How it’s made and used

• Nutrition in breastfeeding mothers⁶

  Mothers avoiding milk proteins while breastfeeding lost fat and ate less protein and calories, even with dietitian help.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.