A higher vitamin C intake in the diet was associated with a better lung function in asthmatic adults. Britton and colleage studied the association between vitamin C and E on lung function in a study involving 2,633 subjects aged 17-70 years old. The authors found that a higher intake of vitamin C was associated with a higher forced expiratory volume in 1 second (FEV1), an important measure performance of lung function measuring amount of air movement within 1 second and a higher forced vital capacity (FVC), a measure of the strength of lung muscles by measuring the maximum amount of air a person can expel from the lungs. An increase in vitamin C of 40mg/d was associated with a significant increase in FEV1 and FVC of 25.0 ml and 23.3 ml, respectively. An increase in vitamin E of 2.2mg was also associated with increase in FEVI and FVC of 20.1 ml and 23.1 ml. The authors concluded that much of the beneficial effect is due to vitamin C. (2)
Vitamin C and Asthma in Children:
Citrus and kiwi fruit intake was associated with less wheezing, shortness of breath, and cough in children with and without asthma. The study, which followed 18,737 children living in Central and Northern Italy, found that those eating the most citrus and kiwifruit (5-7 servings per week) had 44% less incidence of wheezing compared to children eating the least (less than once a week). Shortness of breath was reduced by 32%, severe wheeze by 41%, night time cough by 27%, chronic cough by 25%, and runny nose by 28%. In children aged 6–7?yrs, those who ate at least 5 serving of fruit rich in vitamin C per week were less likely to have respiratory-related health problems including wheezing, shortness of breath, or night coughing compared with those who never ate fruit. Children who had asthma when the study began appeared to benefit the most, and protective effects were evident even among children who ate fruit only once or twice a week. (3)
