Increase in circulating products of lipid peroxidation (F2-isoprostanes) in smokers: smoking as a cause of oxidative damage

Cigarette smoking appears to oxidize fats, which could ultimately lead to atherosclerosis. Researchers took blood and urine samples from 10 smokers before and after they smoked three cigarettes in a 30-minute period. They also took blood and urine samples from 10 nonsmokers. All samples were tested for a group of chemicals called F2-isoprostanes, which are formed in the body when fats are oxidized. Seven of the smokers had higher blood levels of F2-isoprostanes than nonsmokers, even before they smoked the three cigarettes. They also had higher levels of F2-isoprostane metabolites in their urine, and lower levels of vitamin C in their blood. When eight of the smokers stopped smoking for two weeks, their blood levels of F2-isoprostane dropped significantly. Some of the smokers had blood levels of F2-isoprostanes that were not significantly higher than in nonsmokers, indicating that some people may be naturally resistant to the effects of smoking.