Omega-3 levels and nicotine dependence: a cross-sectional study and clinical trial

Abstract

Background: High oxidative stress, which is caused by smoking, can alter omega-3 fatty acid concentrations. Since omega-3 fatty acids plays a role in dopaminergic neurotransmission related to dependence, it is important to understand its effects on nicotine dependence. Methods: This research comprised two studies. The first one consisted of a cross-sectional evaluation, in which the levels of the most important omega-3 fatty acids, EPA and DHA, were compared between smokers and non-smokers in a sample of 171 individuals, of them 120 were smokers and 51, non-smokers. The other study was a clinical, double-blind, randomized, placebo controlled, in which 63 smokers received daily treatment with capsules of fish oil (a source of omega-3/3g per day) or mineral oil (used as placebo, also 3g per day), taken three times a day for 90 days. Each fish oil capsules contained approximately 210.99mg EPA and 129.84mg of DHA. The outcome was evaluated by means of psychometric and biological measures as well as self-reports of tobacco use. The evaluations were carried out at the beginning of treatment and once a month thereafter (total of 4 times). Outcomes: The omega-3 fatty acid lipid profile showed that smokers present lower concentrations of docosahexaenoic acid. After treatment the omega-3 group showed a significant reduction in their levels of dependence. Interpretation: Smokers showed lower peripheral levels of omega-3, and the treatment with the most important omega-3 fatty acids brought about a reduction in nicotine dependence. (AU)