Dietary modulation of oxidative stress in chronic obstructive pulmonary disease patients.

A total of 267 clinically stable chronic obstructive pulmonary disease (COPD) patients provided complete data about diet and oxidative stress markers in order to assess the relationship between antioxidant rich food groups and nutrients, and serum markers of oxidative stress in COPD. Dietary data of the last 2 years was assessed using a validated food frequency questionnaire (122 items). Levels of carbonyls, nitrotyrosine, malondialdehyde and reduced glutathione (GSH) were measured in serum. Vitamin E intake was inversely associated with levels of carbonyls (p = 0.05) and olive oil was positively associated with GSH levels (p = 0.01), in active smokers. Intake of vegetables was related to a decrease of malondialdehyde levels (p = 0.04) in former smokers. No statistically significant associations were found between remaining dietary antioxidants and serum oxidative stress markers. These results provide new data for a potential dietary modulation of systemic oxidative stress in COPD patients, particularly in those that continue smoking.