Prenatal exposure to inflammatory molecules may pave the way for asthma, so researchers are investigating whether dietary and other changes during pregnancy might lower levels and spare children from getting asthma. One of the leading possibilities is increasing intake of the omega-3 fats in fish and some plant-based foods. Omega-3s have well-documented anti-inflammatory effects.

Australian researchers have enrolled about 600 mothers in a clinical trial to test several anti-asthma interventions, including diets high in omega-3s. In 2003, they reported interim results based on tests of their 18-month-old children. The findings were not showstopping, but children of mothers with diets rich in omega-3s during pregnancy were somewhat less likely to have wheezing problems.