Effective promotion of breastfeeding is constrained if health professionals' knowledge on its importance is deficient. This study asks whether formula feeding is named as the risk factor in published research or whether it is considered the unspoken norm. A systematic analysis is conducted of the information content of titles and abstracts of 78 studies that report poorer health among formula-fed infants. This shows a surprising silence in the studies examined; formula is rarely named in publication titles or abstracts as an exposure increasing health risk. In 30% of cases, titles imply misleadingly that breastfeeding raises health risk. Only 11% of abstracts identify formula feeding as a health risk exposure. Initiatives to increase breastfeeding have described the importance of accurate language and well-informed health professional support. If widespread, this skew in communication of research findings may reduce health professionals' knowledge and support for breastfeeding.