By Anne Harding
June 1, 2007
NEW YORK (Reuters Health) – Drinking apple juice from concentrate daily may help ward off asthma symptoms in children, a study from the UK hints.
In a previous study, Dr. Seif O. Shaheen of the National Heart and Lung Institute at Imperial College London and colleagues found that eating apples seemed to protect adults from developing asthma symptoms. A number of other studies have linked higher fruit consumption to better lung function.
It’s possible that the antioxidants contained in fruit counteract harmful oxidative stress due to pollution and ease inflammation, thus reducing asthma symptoms, Shaheen explained. And the antioxidant content of apples is particularly high, the researcher added.
Shaheen’s team analyzed fruit intake and asthma symptoms in 2,640 children aged 5 to 10 years.
While there was no association between asthma symptoms and apples, children who drank apple juice from concentrate at least once a day were at 47 percent lower risk of wheezing than children who drank apple juice less than once a month. “That’s a bit of a puzzle,” Shaheen said, adding that it is possible that juice might have a higher antioxidant concentration than fruit.
Shaheen urges caution in interpreting the study results. “It would be wrong to say that our data suggest that drinking apple juice reduces the risk of asthma,” the researcher said in an interview. “We’ve only shown an association, and we’ve yet to provide definitive evidence that the link is causal.”
The study also found that children who ate bananas at least once daily, compared to those who ate them less than once a month, were also at significantly lower risk of wheezing. But given that the fruit have never been associated with asthma symptoms previously, Shaheen said, this finding is “less convincing.”
The investigators followed up with the same group of children a year later and are currently analyzing the results. If the association persists, Shaheen said, the next step would be to conduct a clinical trial of the effect of apple juice consumption on asthma symptoms.
“Until we have trial data we really can’t be sure,” Shaheen added.
SOURCE: European Respiratory Journal, June 2007.