Breast milk may help ward off human immunodeficiency virus (HIV), according to a new study. Researchers at Duke University have discovered that a compound occurring in maternal milk can kill the virus and protect newborns from becoming infected. The findings help explain why infants with HIV-positive mothers don’t become infected more often than they do.

While scientists have been investigating the apparent antiviral properties of breast milk for some time, the new study is among the first to single out a particular protective compound. The research, which is published in the journal Proceedings of the National Academy of Sciences, focused on a protein known as Tenascin-C, or TNC. According to Sallie Permar, professor of pediatrics and senior author of the study, the discovery could underpin new methods of treating babies born to HIV-positive mothers. In nations with limited access to conventional medication, such methods may revolutionize prevention strategies.

"Even though we have anti-retroviral drugs that can work to prevent mother-to-child transmission, not every pregnant woman is being tested for HIV, and less than 60 percent are receiving the prevention drugs – particularly in countries with few resources," she said in a statement released by the university. "There is still a need for alternative strategies to prevent mother-to-child transmission, which is why this work is important."

Although TNC is known to play a crucial role in pre- and postnatal development, no other studies have illuminated its apparent antiviral and germ-fighting capacity. "TNC is a component of the 'extracellular matrix' that is integral to how tissues hold themselves together," Permar told Health Day. "This is a protein involved during wound healing, playing a role in tissue repair. It is also known to be important in fetal development, but its reason for being a component of breast milk or its antiviral properties had never been described."

That said, more research is needed to determine whether TNC fights HIV on its own or with other substances. Until a conclusive study has been produced, HIV-positive mothers should continue to follow the recommendations of public health agencies like the U.S. Centers for Disease Control and Prevention (CDC), whose guidelines explicitly forbid infected women to breastfeed under any circumstances.

Source: Genevieve G. Fouda, Frederick H. Jaeger, Joshua D. Amos, Carrie Ho, Erika L. Kunz, Kara Anasti, Lisa W. Stamper, Brooke E. Liebl, Kimberly H. Barbas, Tomoo Ohashi, Martin Arthur Moseley, Hua-Xin Liao, Harold P. Erickson, S. Munir Alam, and Sallie R. Permar Tenascin-C is an innate broad-spectrum, HIV-1–neutralizing protein in breast milk. PNAS 2013 ; published ahead of print October 21, 2013, doi:10.1073/pnas.1307336110