In fact, a new study shows that babies who drink high amounts of heat-treated infant formula and other strongly heat-treated milk products may be at a higher risk of developing the condition.
Heat-treated Milk Products During Infancy May Increase Asthma Risk
To conduct this study, researchers evaluated records of 3053 Finnish children that included information on their diets and asthma prevalence—looking specifically at the degree of heat treatment.
Results suggested that consumption of infant formulas and strongly heat-treated milk products was associated with an increased risk of asthma.
Of the children included in the study, 6% were diagnosed with asthma by the age of 5. The October study was published in the journal Pediatric Allergy and Immunology.
“This recent study regarding the level of heat treatment of milk products lends to another possible causation of a risk factor for asthma,” Lauren Sams, MS, RD, a Texas-based pediatric dietitian and breastfeeding specialist and owner of Grow Baby Nutrition + Lactation, tells Verywell.
The risk may be due to the negative effect the heat has on live protective microbes and sensitive proteins and fats in the milk products.
Unlike heat-treated infant formulas and milk products, human breast milk contains a diverse microbiome with a variety of beneficial live bacterial strains. Breastfeeding influences the development of the infant’s oral and gut microbiota, which have both been linked to asthma development.
Previous research shows that exclusively feeding an infant human milk for the first six months of life can reduce the risk of developing allergies and asthma when compared with infants who are fed cow’s milk-based and soy milk-based infant formulas.
And when comparing types of infant formulas, some data suggest that feeding infants with a family history of allergy certain hydrolyzed infant formulas (formulas that contain broken down proteins) versus formula with intact cow’s milk proteins may reduce asthma risk as well, although more studies are needed to confirm this.
How Parents Can Reduce Asthma Risk in Infants
Sams shares that, to reduce the risk of a child developing asthma, “the first recommendation is always exclusive breastfeeding.”
However, if a parent cannot or chooses not to exclusively feed a baby with human breast milk, “hypoallergenic formula should be recommended for an infant with a strong family history of allergies and asthma," Sams explains.
“Several studies have shown that having pets around the house during infancy can decrease the risk of allergies and asthma in childhood,” she adds.
Some data suggest that supplementing infants who are not receiving breastmilk with probiotics may reduce asthma risk, although trials have shown mixed outcomes.
And while this present study suggests that feeding infants breast milk alternatives that are not heat-treated would be the best choice for asthma risk reduction, doing so may increase a baby’s risk of ingesting harmful bacteria. In fact, the American Academy of Pediatrics cautions that consuming raw milk could lead to life-threatening outcomes in certain situations, and advises against offering it to infants and children.
“Infants do not yet have a strongly developed immune system and are at higher risk of illness from non-heat treated milk products,” Kacie Barnes, MCN, RDN, Dallas-based dietitian, and creator of Mama Knows Nutrition, tells Verywell. Heat-treated infant formulas are the options that are commercially available in the U.S.
Overall, when determining how to feed a child, Barnes adds that “the most important factor is that baby is fed.”
“Parents should discuss concerns with their pediatrician to determine which formula is right for their baby if they are unable or choose not to breastfeed,” she advises.
