Consuming greater amounts of certain omega-3 fatty acids found in fish may reduce the risk of asthma in kids -- but only those with a common gene variant, British researchers say.
They focused on the long chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are known to have anti-inflammatory properties.
"Asthma is the most common chronic condition in childhood and we currently don't know how to prevent it," said study senior author Seif Shaheen, of Queen Mary University of London.
"It is possible that a poor diet may increase the risk of developing asthma, but until now most studies have taken 'snapshots', measuring diet and asthma over a short period of time," he said in a university news release.
To find out if intake of omega-3s might matter, the researchers analyzed data on more than 4,500 Britons who were born in the 1990s and whose health has been tracked since birth.
The researchers analyzed the association between intake of EPA and DHA from fish at 7 years of age and rates of newly diagnosed asthma in these kids as they reached 11 to 14 years of age.
Overall, omega-3 intake from fish was not associated with asthma onset. But it did seem tied to a lower odds for asthma in a subgroup of children with a particular genetic makeup.
The DNA in question is a very common variant in the fatty acid desaturase (FADS) gene: More than half of the children had this variant, Shaheen and colleagues said. Kids who have this gene tend to have lower natural levels of long chain omega-3 fatty acids in their blood.
In these children, a higher dietary intake of long chain omega-3 fatty acids was associated with a lower risk of asthma.
In fact, youngsters who ranked within the highest one-quarter in terms of their daily omega-3 intake had a 51% lower risk of asthma than those in the lowest one-quarter, the researchers found. The study was published Jan. 28 in the European Respiratory Journal.
Shaheen's group stressed that this is an observational study, so it cannot prove that higher intake of omega-3s in childhood can prevent asthma.
Audrey Koltun is a registered dietitian nutritionist at Cohen Children's Medical Center in New Hyde Park, N.Y. Reading over the new findings, she said that because of their known benefits against a myriad of ills, "omega-3s from fish are routinely recommended as part of a healthy diet."
But Koltun said the U.K. study leaves many questions unanswered, especially for parents of kids who might be picky eaters.
"Most children do not like fish," Koltun said, "so it would be difficult for those children with the gene variant to benefit from the omega-3s if they dislike fish. Would taking a high-quality fish oil supplement have the same benefits regarding decreasing the risk of developing asthma in this specific group of children?"
Some omega-3 supplements are sourced from plant sources such as algae, she noted, but it's not clear whether those supplements would be of equal benefit against asthma.
For kids, Koltun recommends "aiming for a more balanced healthy diet that is limited in the refined/processed foods" known to boost inflammation in the body. At the same time, parents should try to "increase vegetables, fruit, whole grains as well as healthy fats -- including the omega-3s," she said.
The American Lung Association has more on childhood asthma.
SOURCES: Audrey Koltun, RDN, registered dietitian nutritionist and certified diabetes care and education specialist, Cohen Children's Medical Center, New Hyde Park, N.Y.; Queen Mary University of London, news release, Jan. 28, 2021