Prevention of exercise-induced asthma by a natural isomer mixture of beta-carotene.
BACKGROUND
The unicellular alga Dunaliella bardawil was previously shown to contain very high concentrations of beta-carotene composed of equal amounts of the all-trans and 9-cis stereoisomers which differ in their physicochemical features and antioxidative activity. Due to the controversy regarding the beneficial effect of antioxidants on asthma, the acute effects of beta-carotene of Dunaliella was assessed on airway hyperreactivity in patients with exercise-induced asthma (EIA).


METHODS
Thirty-eight patients with EIA participated in our study to verify the antioxidative effect. The test was based on the following sequence: baseline pulmonary function, 7 minutes exercise session on a motorized treadmill, 8 minutes rest, 1-week oral random, double-blind supplementation of placebo or 64 mg/day beta-carotene, pulmonary functions at rest, 7 minutes exercise session, 8 minutes rest and again pulmonary functions.


RESULTS
All patients given placebo showed a significant postexercise reduction of more than 15% in their forced expiratory volume in one second (FEV1). Of the 38 patients who received a daily dose of 64 mg of beta-carotene for 1 week, 20 (53%) were protected against EIA.


CONCLUSIONS
Our results indicate that a daily dose of Dunaliella beta-carotene exerts a protective effect against EIA in some patients most probably through in vivo antioxidative effect.
Department of Allergy, Hasharon Hospital, Rabin Medical Center, Petach Tivka, Israel.
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Neuman
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Nahum
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Ben-Amotz
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000627:therapeutic use*; D001250:Asthma, Exercise-Induced / Q000517:prevention & control*; D002648:Child; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D010919:Placebos; D012129:Respiratory Function Tests; D013237:Stereoisomerism; D013997:Time Factors; D019207:beta Carotene / Q000008:administration & dosage / Q000627:therapeutic use*
D000975:Antioxidants; D010919:Placebos; D019207:beta Carotene