Dietary antioxidants and asthma in adults.

TitleDietary antioxidants and asthma in adults.
Publication TypeJournal Article
Year of Publication2006
AuthorsPatel, BD, Welch, AA, Bingham, SA, Luben, RN, Day, NE, Khaw, K-T, Lomas, DA, Wareham, NJ
JournalThorax
Volume61
Issue5
Pagination388-93
Date Published2006 May
ISSN0040-6376
KeywordsAged, Antioxidants, Ascorbic Acid, Asthma, Case-Control Studies, Cohort Studies, Diet, Energy Intake, Female, Humans, Male, Middle Aged, Risk Factors
Abstract

BACKGROUND: Several antioxidant nutrients have been reported to be inversely associated with asthma. A study was undertaken to assess the independent associations of these nutrients with asthma in adults.METHODS: A nested case-control study was performed in 515 adults with physician diagnosed asthma and 515 matched controls using dietary data obtained from 7 day food diaries. The main outcome measures were physician diagnosed asthma and current symptomatic asthma (diagnosed asthma and self-reported wheeze within the previous 12 months).RESULTS: Cases were similar to controls in age, sex, social class, and daily energy intake but had a lower median intake of fruit (132.1 v 149.1 g/day, p< or =0.05). 51.5% of the population reported zero consumption of citrus fruit; relative to these individuals, people who consumed >46.3 g/day had a reduced risk of diagnosed and symptomatic asthma (OR adjusted for potential confounders 0.59 (95% CI 0.43 to 0.82) and 0.51 (95% CI 0.33 to 0.79), respectively). In nutrient analysis, dietary vitamin C and manganese were inversely and independently associated with symptomatic asthma (adjusted OR per quintile increase 0.88 (95% CI 0.77 to 1.00) for vitamin C and 0.85 (95% CI 0.74 to 0.98) for manganese), but only manganese was independently associated with diagnosed asthma (OR 0.86 (95% CI 0.77 to 0.95)). Adjusted plasma levels of vitamin C were significantly lower in symptomatic cases than in controls (54.3 v 58.2 micromol/l, p = 0.003).CONCLUSIONS: Symptomatic asthma in adults is associated with a low dietary intake of fruit, the antioxidant nutrients vitamin C and manganese, and low plasma vitamin C levels. These findings suggest that diet may be a potentially modifiable risk factor for the development of asthma.

DOI10.1136/thx.2004.024935
Alternate JournalThorax
Citation Key10.1136/thx.2004.024935
PubMed ID16467075
PubMed Central IDPMC2111195
Grant ListG0401527 / / Medical Research Council / United Kingdom
G0500306 / / Medical Research Council / United Kingdom
MC_U106179471 / / Medical Research Council / United Kingdom