Eating Fish Before Age 1 May Curb Allergy Risk
by Reuters Health

Children who start eating fish before their first birthday may have a lower risk of developing allergies, new research suggests.

In a study that followed roughly 3,000 children from birth to age 4, Swedish researchers found that those who began eating fish before they were 12 months old had lower odds of developing asthma, nasal allergies or the allergic skin condition eczema.

The findings, published in the journal Allergy, can only show an association between early fish consumption and lower allergy risk -- and not that fish directly protects against such conditions.

Still, the study authors point out, their results are in line with evidence that the omega-3 fats in fish support healthy immune system development. One recent study, for example, found that children born to women who took fish oil pills during pregnancy had a reduced allergy risk.

The theory is that because omega-3 fats have anti-inflammatory properties, they affect immune system development in a way that lowers the likelihood of allergies. But whether and when parents introduce fish into their baby's diet is an individual choice. In general, experts advise that babies receive only breast milk for the first 6 months and then have solid foods introduced gradually one at a time.

Some guidelines, including new ones from the American College of Asthma, Allergy and Immunology, advise that children with a family history of allergy not eat fish until age 3.

But in Sweden, guidelines for such families were changed in 2003 due to a lack of evidence that delaying the introduction of fish cuts the risk of fish allergy, noted Dr. Inger Kull, a researcher at the Department of Occupational and Environmental Health in Stockholm and the lead author of current study.

Indeed, growing evidence suggests that introducing fish before age 1 reduces the risk of allergies in general, Kull told Reuters Health. In her study, children who regularly ate fish at some point in their first year were one-quarter less likely than their peers to develop allergies by age 4.The protective effect remained when the researchers excluded children who had eczema or wheezing in infancy or a family history of allergy. This makes it less likely that the findings reflect the fact that parents may not give fish to their children if they have allergies or have a high risk for them.

However, Kull said, more studies are needed before "promoting a special diet" to prevent childhood allergies.

It's possible, for example, that the children's fish intake was simply a "proxy" for other lifestyle factors that protect against allergies, according to the researchers. One possibility, Kull noted, is that their mothers' fish consumption during pregnancy and breastfeeding exposed them to beneficial fatty acids.
Allergy, August 2006