RESUMO
BACKGROUND: Smoking-induced oxidative stress is thought to contribute to lower levels of omega-3 fatty acids in plasma and brain tissue. This lower level leads to impaired function in a dopaminergic system related to dependence and craving. AIMS: The aim of this study was to evaluate the effects of omega-3 fatty acid supplementation on cigarette craving and oxidative stress index in heavy-smoker males. METHODS: In this double-blind, randomized clinical trial, 54 heavy-smoker males (smoke ⩾20 cigarettes per day) were randomly selected to receive either five capsules of fish-oil-derived omega-3 fatty acid supplements ( n = 27, each 1 g capsule containing 180 mg of eicosapentaenoic acid and 120 mg of docosahexanoic acid) or a placebo ( n = 27) for 3 months. The psychometric evaluations (nicotine dependence and cigarette craving), biochemical markers (urinary cotinine, serum total antioxidant capacity and total oxidant status) and self-reported smoking status were used to assess the cigarette craving and oxidative stress index (oxidative stress index = total oxidant status/total antioxidant capacity). RESULTS: There was a greater reduction in levels of nicotine dependence, cigarette craving and cigarettes smoked per day in the omega-3 fatty acid group compared to the placebo group, and the difference between the two groups increased from baseline to 3-month follow up. The model estimated that these differences were statistically significant ( p < 0.001, p < 0.001 and p < 0.001, respectively). Also, a significant decrease was observed in levels of total oxidant status ( p = 0.008) and oxidative stress index ( p = 0.011) in the omega-3 fatty acid group after intervention. CONCLUSIONS: This study showed that high-dose omega-3 fatty acid supplementation appears to be useful in reducing cigarette craving and oxidative stress index in heavy-smoker males.