Use of a food frequency questionnaire on Chinese diet to assess antioxidant status in individuals with asthma

Abstract

It has been suggested that dietary antioxidants have a protective role in asthma. However, validated dietary questionnaires have mostly been carried out in the western populations. In this study we investigated: 1) the relationship between dietary intake of carotene and vitamin E as well as their plasma levels in asthmatic patients and healthy subjects; and 2) the validity of a food frequency questionnaire (FFQ) by comparing dietary intake with plasma levels in the Chinese population. A case-control study was carried out on 39 asthmatic patients and 33 healthy subjects. Dietary data of carotene and vitamin E were obtained by a FFQ. β-Carotene and α-tocopherol in plasma were also measured. Significant positive correlations were found between plasma β-carotene levels and carotene intake as well as between plasma α-tocopherol levels and vitamin E intake. No differences in antioxidant intake and their plasma levels were seen between asthmatic patients and controls. Our study supports the validity of FFQs use in nutrient assessments in the Chinese population.