Oily fish during pregnancy may reduce the risk of asthma in babies.
Women who ate salmon twice a week from week 19 of their pregnancy gave birth to children who were significantly less likely to have asthma.
The children were tested at six months and then again at two to three years of age.
The six month test showed no difference in the allergy rate but at two and a half years of age the children whose mothers ate the fish were less likely to have asthma.
Prof Philip Calder of the University of Southampton, who carried out the research has won international awards for his nutrition work.
He told a Biology Congress in San Diego that early results, which are yet to be published, showed the difference was notable at two and a half years of age.
Prof Calder has already been involved in ground breaking research into specific relationships between nutrition and immune-related conditions over the course of a human lifetime.
“Our new findings from the Salmon in Pregnancy Study indicate that early nutrition interventions, even during pregnancy, can have long lasting effects on health,” he said.