Apples may improve lung function, researchers say

Eating five or more apples each week may improve lung function, a study suggests. Ms Barbara Butland (department of public health sciences, St Georges medical school, London) and colleagues say that “a strong positive association is seen between lung function and the number of apples eaten per week”. This protective effect was not observed with soft or citrus fruit.

In a study of 2,512 Welsh men, forced expiratory volume in one second (FEV1) was measured at baseline and after five years. Dietary information was recorded by questionnaire. A high FEV1 was associated with high consumption of vitamins C and E, beta-carotene, citrus fruits, apples and fruit juices, the authors report. However, after adjustment for factors such as body mass index, smoking history, social class, exercise and total energy intake, the only dietary links remaining were with vitamin E and apples, they say. Lung function was estimated to be 138ml higher for people eating five or more apples per week.

The authors suggest that the effect may be because apples contain high levels of an antioxidant, quercetin. Quercetin protects the lungs from the effects of cigarette smoke and atmospheric pollutants. It is also found in onions, tea and red wine (Thorax 2000;55:102).