Studies show cow-milk baby formula products can cause deadly intestinal disease in premature babies | Causes, Not Just Cases®

Necrotizing enterocolitis (NEC) is a gastrointestinal disease that affects the most vulnerable among us – premature infants. It is a serious, sometimes fatal condition with potentially lifelong consequences. While NEC is a known risk for preterm infants, researchers have found that a seemingly innocent sources can significantly increase its occurrence – bovine, or cow’s milk-based, formula and fortifier. 

The Dangers of Cow’s-Milk-Based Formula and Fortifier for Preterm Infants

Cow-milk based infant formula has been available in the United States since the late 19th Century. Cow’s milk is also used in fortifiers, which are protein and mineral supplements added to breast milk to boost its nutritional value. For several decades, formula and fortifiers based on cow’s milk were given to preterm infants. However, over a period of several decades, NICU nurses, doctors, and researchers began noticing a possible link between formula and fortifiers based on cow’s milk and NEC. 

Literature today suggests premature infants who are fed bovine-based formula and/or fortifier are nearly 2 to 10 times more likely to develop NEC. This connection has been known in the medical community since at least 1990, when a study found formula-fed babies were 6 to 10 times more likely to develop NEC compared to those fed breast milk. In 2006, the World Health Organization released a review that found “strong and consistent evidence that feeding mother’s own milk to pre-term infants of any gestation is associated with a lower incident of infections and necrotizing enterocolitis ...” Now, it is widely accepted that “[p]remature infants fed formula are more likely to develop [NEC] than those who are breastfed.”

Preemies and NEC

NEC is an intestinal disease, characterized by inflammation and injury to the wall of the gut. Infants, especially preterm infants, are at a higher risk of NEC because premature infants are born with underdeveloped bowels that are prone to infection. This fact, coupled with the lack adequate oxygen flow at birth, which is also common with preterm infants, means the intestinal wall cannot adequately fight infection. Why babies fed pure breast milk are less likely to develop NEC is not completely understood, studies show breast milk better protects these sensitive bowels. Feeding a premature or low birth weight baby cow-based formula or supplements can inflame the bowel, and in some cases cause a rupture and leak harmful bacteria and other material into the infant’s abdominal cavity. 

Premature babies often have nutritional deficiencies, and hospitals have for many years sought to improve those deficiencies by substituting formula for breast milk or fortifying breast milk with cow’s milk-based fortifiers. Unfortunately, feeding preemies formula or fortifying the breast milk they’re fed has in many cases led to dire consequences.

A 2019 study found roughly 20 to 40% of NEC cases result in surgery, and tragically, between 20 to 67% of all NEC cases are fatal. The long-term side effects of moderate-to-severe NEC are also significant. Survivors of NEC may suffer from numerous gastrointestinal and neurodevelopmental issues and grow more slowly.

Neurological Injuries Associated with NEC

Sadly, NEC can lead to long-term neurological impairment and conditions like cerebral palsy because the infection that begins in the intestinal wall can spread to other organs of the body. Studies show 45% of NEC survivors are at a higher risk of cerebral palsy, hearing, visual, cognitive, and psychomotor impairments at 20 months of age. In fact, 20% of neonates with NEC developed cerebral palsy, 3% developed visual, 3% hearing, 36% cognitive and 35% psychomotor impairment.

For survivors of severe NEC, the incidence of neurological issues does not lessen with age. At two, survivors of severe brain injury are more likely to have severe brain injury detected on MRI, as well as poor mental and psychomotor development at 2 years of age. At school age, various cognitive deficits of severe NEC survivors persist, including lower IQs and poorer attention and visual perception. 

Approximately 10.1% of the infants born in the United States were premature, born at or before 37 weeks, in 2020, and thousands of babies sadly develop NEC each year. 

Current evidence strongly supports a connection between cow milk products and NEC. Manufacturers of baby formula and fortifier products owe it to families to produce safe products and hospital systems must reconsider their policies in to protect the most vulnerable among us who are not capable of protecting themselves. 


Subscribe to our blog if you’d like to have more content like this sent directly to your inbox.