How about that

Omega-3 Fatty Acids May Help to Reduce the Physical Harm Caused by Smoking

The study, carried out in Greece, assessed the effect of four-week oral treatment with 2 g/day of omega-3 fatty acids on the arterial wall properties of cigarette smokers. The results showed that short-term treatment with omega-3 fatty acids improves arterial stiffness and moderates the acute smoking-induced impairment of vascular elastic properties in smokers.

Um, that is not a correlative study, and it shows some pretty dramatic results.