Eating oily fish such as salmon or trout during pregnancy appears to help protect babies predisposed to asthma from developing the condition during their first years of life, according to new study findings reported this week.
Eating oily fish such as salmon or trout during pregnancy appears to help protect babies predisposed to asthma from developing the condition during their first years of life, according to new study findings reported this week. A family history of asthma puts children at risk of developing the disease themselves, said study author Dr. Frank Gilliland. Among children of asthmatic women, those whose mothers ate oily fish regularly during their pregnancies were 70 percent less likely to develop asthma before age 5 than children whose mothers never ate oily fish while pregnant. And the more oily fish an asthmatic woman ate while pregnant, the less likely her child was to develop asthma. These findings suggest that omega-3 fatty acids in oily fish somehow dampen the type of inflammation involved in asthma in children predisposed to the condition, he explained. “The basic idea is that (oily fish) turns down the inflammatory response,” he said. However, the University of Southern California in Los Angeles researcher cautioned that many types of oily fish contain a large amount of the pollutant mercury, which can interfere with fetal mental development. To get around this, Gilliland said that pregnant women may be able to obtain the same respiratory benefits for their children by taking fish oil supplements, which likely contain less mercury than fish. He pointed out, however, that researchers have not yet demonstrated that supplements rich in omega-3 fatty acids carry the same anti-asthma benefits as oily fish, and pregnant women should not change their eating habits solely based on the findings from this study. “More work needs to be done before we can get to that point,” Gilliland said. Gilliland and his colleagues presented their findings during the American Thoracic Society International Conference, held in Orlando, Florida. The researchers interviewed 691 mothers, half of whom had children who developed asthma before the age of 5. Mothers reported how often they ate oily fish while pregnant years before. Gilliland and his team found that children whose mothers were asthmatic and ate oily fish between once a week and once a month while pregnant were 70 percent less likely to develop asthma than children of asthmatic mothers who said they never ate oily fish while pregnant. Eating oily fish during pregnancy appeared to have no effect on the risk of asthma in children with no family history of asthma. In an interview, Gilliland suggested that children with no family history of asthma may develop the condition via other mechanisms than children who are genetically predisposed to it, and those non-hereditary mechanisms may be less influenced by oily fish. (Source: Reuters Health, May 2004)