Overweight preschoolers have a grater risk to develop asthma by the time
they are 7-years old, but losing weight early on may counter this risk, according to researchers at Karolinska Institute in Stockholm.
Following the study of 2,000 Swedish children researchers found that children who were overweight at ages 1, 1.5, 4 and 7 were up to twice as likely to have asthma by age 8 as normal-weight children. However, overweight children who reached a normal weight by age 7 were no more likely to have asthma by the time they turned 8. Children who were overweight at age 7 also had a higher risk for allergies.
Researchers feel there may be several biological explanations for the link between being overweight and asthma.
One possible explanation may involve the hormone leptin, which is derived from fat
and is found in higher amounts in people who are overweight and previous
studies have suggested that leptin may cause exaggerated inflammatory
responses by the immune system, which is a key feature of asthma.
The study has been published in the journal Pediatrics.