Free radical biology & medicine
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Free Radic. Biol. Med. · May 2006
Randomized Controlled TrialVitamin supplementation does not protect against symptoms in ozone-responsive subjects.
Vitamin supplements have been reported to reduce the magnitude of symptoms in subjects exposed to oxidant air pollution. To confirm whether supplementation with vitamins C and E could reduce lung function decrements, airway inflammation, and epithelial injury in subjects sensitive to ozone, a double-blinded, crossover control study was performed. Fourteen ozone-responsive subjects were randomly exposed to both air and ozone (0.2 ppm for 2 h) after 7 days of either placebo treatment or supplementation with vitamin C (500 mg/day) and E (100 mg/day). ⋯ Similarly, ozone-induced neutrophilia were of a similar magnitude after both treatments (P < 0.05). This lack of protection was observed despite elevated plasma vitamin C (+60.1%) and vitamin E (+51.4%) concentrations following supplementation, and increased vitamin C concentrations in the airways after supplementation following ozone exposure. These data do not therefore support the contention that acute ozone-induced symptoms can be attenuated through the use of dietary antioxidants in well-nourished individuals.