Breast Milk Causes More Cavities Than Cow Milk, According To New Study

The University of Rochester Medical Center study is published in the October edition of Pediatrics. It warns parents to stop allowing babies to drink sugary liquids from bottles, or to sweeten water with honey, which has been promoted as good for dental health, or to let babies fall asleep on the nipple.

The authors do not advocate switching from breastfeeding to cow milk, nevertheless they do alert nursing mothers to the need for oral hygiene after feedings, especially when the infant’s first teeth have begun to emerge.

“In families where cavities are prevalent, there’s also an urgent need to avoid feeding all night once the teeth have erupted,” said Ruth A. Lawrence, M.D., author of “Breastfeeding: A Guide for the Medical Profession,” and professor of Pediatrics at the University of Rochester Medical Center’s Golisano Children’s Hospital.

A breastfeeding supporter, Lawrence co-authored the cavities study with William H. Bowen, D.D.S., Ph.D., the University of Rochester Welcher Professor of Dentistry, and one of the world’s leading authorities on tooth decay. Bowen has carried out extensive studies on the interactions of bacteria and food that occur on the tooth surface, resulting in dental plaque formation, and on conditions that may inhibit the production of saliva, a natural shield against cavities.

The current study, funded by the National Institutes of Health, was conducted in rats using an approach that mimics the situation among infants and toddlers who are allowed to indulge in protracted feeding. The authors report that artificial and human nipples may restrict the flow of saliva, which promotes cavities, or caries.

Researchers assigned each liquid substance an arbitrary value of 1, and scored the cariogenicity of each substance based on the number and severity of lesions that developed on the rats’ teeth over 14 days.

The results: sucrose, 1; cola, 1.16; honey, 0.88; human milk, 0.29; cow milk, 0.01. The data confirms previously published research showing the relatively low cariogenicity of cow milk, and also showing that human milk is no worse for teeth than many infant formulas. Scientists hypothesize that the cavity-causing difference between human milk and cow milk may be the mineral content in human milk.

“Obviously, cola and other sugary drinks and honey are highly cavity promoting and erosive to teeth, and should be actively discouraged in children,” Bowen said. “Early caries is costly to treat and may carry additional burdens on the health of children, yet despite greater awareness it continues to plague a significant part of the population.”