Infant formula kills infants through cytotoxicity

Tuesday, December 18, 2012 by: David Gutierrez, staff writer
Tags: infant formula, cytotoxicity, premature death

(NaturalNews) Infant formula has been implicated as possibly a major causes of death in premature newborns, in a study conducted by researchers from the University of California-San Diego (UCSD) and published in the journal Pediatric Research.

For many years, scientists have known that premature infants fed formula are significantly more likely to develop an often fatal condition known as necrotizing enterocolitis than those fed breast milk. Necrotizing enterocolitis is the most common gastrointestinal disease to cause death in premature infants, but its underlying causes have been largely unknown.

In a prior study, the UCSD researchers learned that free fatty acids are naturally formed as a side effect of the human digestive process, and that these fatty acids sometimes act like a "detergent" that kills cells by rupturing their membranes. However, such cell death (cytotoxicity) is rare in humans and in older children, perhaps due to the layer of mucus that coats the intestines. Because the intestines of newborns - especially premature ones - are not as well coated, the researchers wondered if free fatty acids might not be to blame for necrotizing enterocolitis.

Formula kills intestinal and immune cells

In a study funded by the National Institutes of Health, the researchers used pancreatic enzymes or intestinal fluid to digest breast milk and nine different infant formulas that are marketed for preterm and full-term infants. They tested the digested milk and formula for levels of free fatty acids, then added the fatty acids to cells known to be involved in necrotizing enterocolitis.

The cells tested were those lining the intestines (epithelial), those lining the blood vessels (endothelial) and neutrophils, a variety of white blood cell that is one of the first cell types to respond to trauma-induced inflammation.

Across the board, formula digestion produced free fatty acids that killed all three types of cells, whereas breast milk digestion produced little or no cell death. For example, between 47 and 99 percent of neutrophils died when exposed to digested infant formula, but only six percent of the neutrophils died when exposed to digested breast milk. In some cases, the digested infant formula caused cell death in fewer than five minutes.

The researchers found that the body seems to digest breast milk in a slower, more controlled way than it digests most foods, leading to a lower release of free fatty acids. This appears to be an adaptive mechanism to prevent cell death in an infant's developing digestive system.

Because the risks of feeding formula to premature babies are well-known, many neonatal intensive care units have been making efforts to end the practice. Pediatric gastroenterologist and UCSD professor Sharon Taylor said that the study should help support such efforts. She noted that although breast feeding premature infants is difficult, hospital staff can enable it by helping mothers pump their breast milk, which can then be fed to premature infants through a tube.

The study suggests that infant formula may pose a risk to any infant with gastrointestinal problems, not just those born prematurely.

Sources:

http://www.sciencedaily.com/releases/2012/12/121210124616.htm