Why Parents are Choosing Lactose Free and Reduced Lactose Formula

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Whether your baby takes breast milk or infant formula, you’ve likely heard about lactose. But what is lactose? And why is it an important ingredient in most infant formulas? Are there reasons certain babies shouldn’t have lactose?

These are all critical questions for any new parent. We sat down with researcher Bridget Young, Ph.D., Assistant Professor of Pediatric Allergy and Immunology at the University of Rochester School of Medicine and Dentistry to learn more about lactose, its role in baby formula, and what you need to know about it. So let’s talk lactose!

Infographic on lactose in human breast milk

What exactly is lactose?

This question is an excellent place to start. First things first – here are the major nutrient components of breast milk and cow’s milk-based infant formula

  • Carbohydrate: Lactose is the main carbohydrate in breast milk and most cow’s milk-based formulas. However, there are often other carbohydrates used in cow’s milk-based infant formulas (more on this later).
  • Protein: The proteins in both breast milk and milk-based infant formula are whey and casein. 
  • Fat: Usually, this is a blend of vegetable oils that provides similar nutrition to the palmitic, oleic, linoleic, and linolenic fatty acids in breast milk.
  • Vitamins and minerals: Iron is one of the essential minerals in infant formula because it prevents anemia. There are also many other vitamins and minerals in infant formula, like calcium and folic acid. 
Lactose in Infant Formula Ingredient Guide

Are there babies who shouldn’t have lactose?

Yes! But luckily, not too many. Parents often wonder if their baby might have lactose intolerance (especially if you do), but the kind of lactose intolerance that happens slowly over time in older kids and adults doesn’t usually start this young. According to Dr. Young, healthy term infants have all the machinery needed to digest lactose from either breast milk or formula.

Here are a couple of conditions that make a baby unable to digest lactose

  1. Congenital lactase deficiency: While babies don’t usually have the same type of lactose intolerance as older kids and adults, there is a very rare genetic disease called congenital lactase deficiency that makes them unable to digest lactose. 
  2. Galactosemia: Another rare genetic condition that leaves babies unable to have lactose.

Are reduced lactose formulas helpful for colic and spitting up?

OK, let’s dive into this one because it’s a little complex. 

According to Dr. Young, “lactose reduced is any formula that’s not 100% lactose, so some of the lactose has been removed. And when lactose is removed, they have to replace it with something to keep the calories, like glucose or sucrose. Formula that’s labeled as sensitive is often lactose reduced, but not always. The only way to know for sure if a formula is lactose-reduced is to check the list of ingredients.”

Of course, when you feel your baby is upset from prolonged crying or spitting up, you look for any possible way to help them feel better. And if their behavior seems related to eating, you might wonder if changing infant formulas could be the answer.

Infographic on reduced lactose formula

Lactose intolerance vs. a cow’s milk allergy

First, it’s important to understand the difference between babies who can’t have lactose (carbohydrate) and those who have a milk allergy, which means they are allergic to the protein. 

Babies with a cow’s milk protein allergy often need hypoallergenic formula, where the protein is more broken down and less likely to be allergenic. These babies may have symptoms like vomiting or fussiness with a routine, cow’s milk-based formula. It’s always important to talk with your baby’s healthcare provider if they have any of these symptoms so you can get to the bottom of what’s going on.²

For babies without an allergy or medical problem who are fussy, gassy or have colic, can low lactose baby formula or lactose-free formula help? There isn’t strong evidence to support this.³,⁴ That being said, doctors may still recommend trying this sometimes because it’s a safe option, even if it isn’t guaranteed to help.²

What to look for when buying baby formula

First, it’s VERY important to know that all infant formula manufactured and sold in the US is FDA regulated.

US infant formulas are FDA regulated and safe. So, if your baby is healthy and thriving, then you have found the right formula for them!”

Dr. Young

Second, if your baby’s doctor has recommended a specific formula, especially if your baby has a medical condition, it’s important to stick with that formula. If your baby is having trouble with that formula, always call their doctor to discuss what to do instead of making changes yourself.

Formula with lactose as the sole carbohydrate

It isn’t entirely clear if you should be looking for a formula with lactose as the only carbohydrate. That’s where infant formula researchers like Dr. Young come in. 

The EU has more restrictions around the use of non-lactose carbohydrates in formula manufactured in Europe, as compared to the US. In Europe, carbohydrates like sucrose and glucose are only allowed to be used in special formulas, not standard cow’s milk-based formula.⁵

According to Dr. Young, there is no definitive research showing that non-lactose carbohydrate sources cause any negative long-term outcomes in babies. However, there is concern that carbohydrates like sucrose, glucose, and fructose may increase the sweetness of milk and lead a baby to overeat and prefer sweet foods.⁶

We need more research in this area. We really need to understand the metabolic implications of lactose alternatives. Meaning, we need to know the biological implications of consuming lactose-reduced and lactose-free formula on infant developmental outcomes.”

Dr. Young

What can you expect to find on baby formula labels

It turns out that finding out whether a formula has other carbohydrates besides lactose in it isn’t as easy as you might think. These details are not spelled out on baby formula labels.

Dr. Young’s recent research, which was presented at the American Society for Nutrition’s annual conference in 2021, showed that 55% of all term infant formula consumed in the US is lactose-reduced, meaning the carbohydrate source is not 100% lactose. She estimates that only about 7.5% of infants medically need a lactose-reduced or lactose-free baby formula.⁷ 

This means that many more babies are getting lactose-reduced or lactose-free formula than may need it for a medical reason. Again, that doesn’t necessarily mean it’s less healthy; this just tells researchers like Dr. Young that there is more to learn on this topic. 

Besides learning more about which carbohydrates are best for babies, there is also more to learn about how infant formulas are marketed and what role this plays in what parents buy. “Infant formula is often marketed with appealing words,” stated Dr. Young, although her study did not look at labeling and how it compared to ingredients. 

For example, a formula may advertise that it helps reduce infant crying, fussiness, or gas. However, if any ingredients have been added or changed in these varieties, this may only be noted in the ingredient list, not on the front of the container. 

Additional research on lactose-reduced infant formulas

As with so much in the research world, Dr. Young’s work opens the door to important areas of further research. Besides looking more closely at different carbohydrates in different formulas, she is also interested in studying other nutrients like iron and vitamin D— how they are different between formulas and what this means for babies. 

While there is more to learn about the differences between each type of formula and what they mean, she wants all parents to know one thing for sure:

Having a baby in the US is very hard. My personal recommendation to parents is always, if your baby is healthy and thriving, you have found the perfect formula! You’re on it, and you’re doing a great job!

Dr Young

Dr. Young was a co-author on the abstract titled ‘Lactose-Reduced Infant Formulas Are Over-Consumed Whereas Hypoallergenic Infant Formulas Are Not – When Compared to Medical Necessity’ which was presented at NUTRITION 2021 LIVE ONLINE as a virtual poster presentation. For the abstract for this presentation, click here. NUTRITION 2021 LIVE ONLINE is the annual flagship meeting of the American Society for Nutrition. Session recordings are available for purchase on ASN on Demand, ASN’s online nutrition research and education resource.


1- Infant formulas | Pediatrics in Review

2- Infant formula | American Family Physician

3- Dietary modifications for infantile colic | The Cochrane Database of Systematic Reviews

4- Lactose-free milk or soy-based formulas do not improve caregivers’ distress or perceptions of difficult infant behavior | Journal of Pediatric Gastroenterology and Nutrition 

5- ​​Commission Delegated Regulation (EU) 2016/127 of 25 September 2015 supplementing Regulation (EU) No 609/2013 of the European Parliament and of the Council as regards the specific compositional and information requirements for infant formula and follow-on formula and as regards requirements on information relating to infant and young child feeding | European Union law

6- Infant food applications of complex carbohydrates: structure, synthesis, and function | Carbohydrate Research

7- Lactose-reduced infant formulas are over-consumed whereas hypoallergenic infant formulas are not- when compared to medical necessity | Current Developments in Nutrition

The content on this site is for informational purposes only and not intended to be a substitute for professional medical advice, diagnosis or treatment. Discuss any health or feeding concerns with your infant's pediatrician. Never disregard professional medical advice or delay it based on the content on this page.

The content on this site is for informational purposes only and not intended to be a substitute for professional medical advice, diagnosis or treatment. Discuss any health or feeding concerns with your infant’s pediatrician. Never disregard professional medical advice or delay it based on the content on this page.