Two studies in respected European journals have linked consumption of apples and apple juice with decreased symptoms of asthma.

Published in the September 2007 issue of Thorax, the latest study finds that when women ate apples during pregnancy, researchers found a significant decrease in asthma and wheezing among their children when the children were followed over five years and reached five years of age.

This unique longitudinal study tracked dietary intake by 1253 mother-child pairs. According to the researchers that conducted medical evaluations for asthma and related symptoms (i.e., wheezing) in the children, they found no other association with decreased risk other than for apple consumption. The only other positive association found between prenatal food intake and risk reduction in the children was with fish intake by the mothers, for which the researchers found that children of mothers who ate fish had a lowered incidence of doctor-confirmed eczema.

A similar but different study published June 2007 also showed a link between apple juice consumption and a reduction in wheezing among children. That study was published in June's European Respiratory Journal.

Among children who experienced what was characterized as "current wheeze" (where the child had wheezing or whistling in the chest in the last 12 months), there was a significant, dose response association between consumption of apple juice and a reduced incidence of the wheezing. The researchers found that drinking apple juice made from concentrate and consumption of bananas one or more times a day (compared to drinking apple juice or eating bananas less than once a month) was directly associated with improvement of wheezing occurrences.

According to the authors of the Thorax paper, the protective effect from apples is attributable to their powerful phytochemical content, which includes flavonoids, isoflavonoids, and phenolic acids. Apples and apple products combined are the largest source of free phenolics in people's diet in the US and in Europe.

The American Lung Association states that asthma remains a major public health concern. In 2003, approximately 20 million Americans had asthma and the condition accounted for an estimated 12.8 million lost school days in children. Asthma ranks within the top ten prevalent conditions causing limitation of activity and costs our nation $16.1 billion in health care costs annually.

References:

Willers et al. Maternal food consumption during pregnancy and asthma, respiratory and atopic symptoms in 5-year-old children. Thorax 2007; 62: 772-778.

Okoko et al. Childhood asthma and fruit consumption. Eur Respir J 2007 29: 1161-1168.

http://thorax.bmj.com