HIV-positive mothers have long been advised to protect their newborns from infection by feeding them formula rather than breast milk. In areas of Africa where clean water isn’t always available, though, mothers have to augment infants’ diets with breast milk, a seemingly logical compromise that POZ (July-Aug. 2007) reports is actually the worst possible approach. Studies show that alternating bottle and breast doubles the risk of transmission compared to exclusively breast-feeding. Mixing in solid foods increases the odds of infection even more.

Large proteins in formula and solid foods can irritate an infant’s digestive tract, which increases the chance of HIV transmission, explains Science News (Sept. 22, 2007). Intermittently breast-fed infants also miss out on antibodies in breast milk that scientists believe inhibit transmission of the virus.

While the reasons for resistance “remain murky,” for infants between the ages of six weeks and six months who are breast-fed only, the risk of transmission is just 4 percent.

To reduce risk further, the World Health Organization recommends that HIV-positive mothers pasteurize or boil their milk. And there may soon be a less costly, less time-consuming alternative. California (Sept.-Oct. 2007) reports on promising research into flash-heating breast milk over an open flame, which might eliminate the virus without damaging the milk’s nutritional properties.