Lactose intolerance and cow's milk allergy in infants compared
What it found
In infants, lactose intolerance and cow's milk allergy cause similar gut symptoms but have different causes.
One is a problem digesting milk sugar, the other is an immune reaction to milk protein.
What they found
Different causes
Lactose intolerance happens when the body does not make enough lactase, the enzyme that breaks down lactose, or when too much lactose is eaten. Cow's milk allergy is an immune reaction to milk proteins, especially casein and beta-lactoglobulin.
Similar gut symptoms
Both conditions can cause vomiting, diarrhea, abdominal pain and gas, so parents and doctors may confuse them. This can lead to wrong or delayed diagnosis.
Types of lactose intolerance
There are four types: developmental (in premature infants), congenital (a rare inherited defect), primary (the most common, starting after age 1), and secondary (caused by damage to the small intestine, often from gastroenteritis).
Diagnosing lactose intolerance
The hydrogen breath test is the method of choice, with sensitivity of 76 to 100% and specificity of 90 to 100%. A jejunal biopsy is the gold standard but is invasive and rarely used outside research.
Diagnosing cow's milk allergy
The gold standard is a double-blind placebo-controlled food challenge, but it is seldom done in daily practice. An elimination diet followed by reintroduction is often used instead.
Treatment differences
Formula-fed infants with lactose intolerance should get reduced or no lactose formula. Those with cow's milk allergy need formula with extensively hydrolyzed milk protein or amino acids. Lactose restriction is only needed in cow's milk allergy if there is also secondary lactose intolerance.
What the authors conclude
“Lactose intolerance (LI) is a non-immunologic reaction to cow’s milk carbohydrate, while cow’s milk allergy (CMA) is an immunologic reaction to cow’s milk protein.”
Also in their conclusions
- They stress that knowing the differences between lactose intolerance and cow's milk allergy is key to accurate diagnosis and treatment.
- They advise that formula-fed infants with lactose intolerance should be treated with a reduced- or no-lactose diet, while those with cow's milk allergy should be treated with formula containing hydrolyzed cow's milk protein or no cow's milk protein.
- They note that lactose restriction is only warranted among cow's milk allergy patients with secondary lactose intolerance.
How it was done
Parents and some healthcare professionals often confuse the two conditions, which can lead to delayed diagnosis and unnecessary dietary restrictions that may pose nutritional risks.
The authors reviewed existing medical literature on lactose intolerance and cow's milk allergy in infants, including their causes, symptoms, diagnosis and management.
What it can’t tell you
- This is a review of existing literature, not a new study, so it cannot provide new data on how common these conditions are or how well treatments work.
- It cannot show whether one formula is better than another for individual infants, because it did not compare treatments directly.
Who paid
- Funding
- Funded by Danone Specialized Nutrition Indonesia (from the PubMed record).
- Conflicts
- N.S. is an employee of Danone Specialized Nutrition Indonesia. A.D. and K.R.S. have received funding for educational consultancy work from Danone Specialized Nutrition Indonesia. J.J. has no conflict of interest.
- Authors work at
- Dr. Soetomo General Academic Hospital, Indonesia; Universitas Airlangga, Indonesia; Universitas Pelita Harapan, Indonesia
The paper
- Title
- Lactose Intolerance versus Cow's Milk Allergy in Infants: A Clinical Dilemma
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Summarised from
- Full text
- Cite
- Darma A, Sumitro KR, Jo J, Sitorus N (2024). Lactose Intolerance versus Cow's Milk Allergy in Infants: A Clinical Dilemma. Nutrients. doi:10.3390/nu16030414Free full textPubMed 38337698DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error