Bananas, Pineapple and Apple Juice Protective Against Asthma Symptoms
According to the American Lung Association, almost 20 million Americans suffer from asthma. The condition is responsible for over 14 million lost school days and children. In a collection of studies, eating certain fruits appears to be protective against asthma symptoms such as wheezing and inflammation.
Antioxidants and Fiber are Protective Nutrients
The first study, conducted by researchers from the National Heart Group and Lung Institute at Imperial College, surveyed 2,640 children between the ages of five and ten. The questionnaires assessed fruit consumption and frequency of asthma symptoms. Children who ate one banana a day had a 24% less chance of developing asthmatic symptoms.
While whole apples did not appear to be protective, drinking one glass of apple juice from concentrate per day was associated with a 47% reduction in current wheezing.
A second study, performed by NIH Postdoctoral Fellow Dr. Eric Secor at the University of Connecticut, tested the effects of bromelain, a enzyme found in pineapples, on laboratory mice. During the eight day study, bromelain significantly reduced total white blood cell count, which increases with the onset of asthma. In addition, eosinophils, cell markers for inflammatory asthma, were also reduced by more than 50%.
Antioxidant intake, particularly of vitamins C and E; are linked to a decreased incidence of asthma. Fruits and vegetables are particularly high in antioxidants, particularly if they are deep colored. Some research indicates that asthma sufferers have low serum levels of certain antioxidants, particularly vitamin C and beta-cryptoxanthin (found in red and orange colored fruits and vegetables).
Additionally, foods high in fiber including fruits, vegetables and whole grains, can help asthma sufferers by promoting weight loss. A French study of over 60,000 women found that those who gained more than 20 pounds between puberty and adulthood had a 66% higher risk of developing asthma. Excess weight promotes inflammation and higher levels of estrogen and leptin which appear to interfere with the functioning of the muscle cells lining the lungs and air passages.
Obese children with asthma find it harder to control their symptoms, have more flare-ups, and make more ED visits than asthmatic children of normal weight, placing the burden of higher health care costs on families.
“It is yet another reason why we should be encouraging a healthy diet,” said Dr. Mike Thomas, researcher for Asthma UK, a British charity based at the University of Aberdeen.
- Dole Food Company Inc.
- Okoko BJ, Burney PG et al. “Childhood asthma and fruit consumption in South London” European Respiratory Journal
- Quingo KB, Zuraw BL et al. “The association of obesity and asthma severity and control in children” Journal of Allergy and Clinical Immunology
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