Numerous small (n~100), single-center randomized trials have shown a benefit of omega-3 fatty acids in acute lung injury and ARDS (reduced mortality, length of stay, and organ failure; improved oxygenation and respiratory mechanics). A meta-analysis combining these studies suggested a stat.significant benefit in mortality (risk ratio 0.67), ventilator requirement (-5 days), and ICU stay (-4 days).

In JAMA, Rice et al pop the balloon ... and something about those earlier trials suddenly smells fishy. In the NHLBI-funded OMEGA study, they randomized 272 adults with ALI/ARDS to receive either twice daily omega-3 fatty acids plus antioxidants, or placebo.

OMEGA was stopped early for futility, which may have been an understatement: the intervention patients had 3 fewer ventilator-free days (p=0.02), 3 more days in the ICU (p=0.04), and an absolute 10% increase in mortality (26.6% vs. 16.3%, p=0.054, just barely not stat.significant).

Unbelievably, an accompanying editorial tries to put a positive spin on this and repair the damage, proposing various theoretical and (to me) flimsy ways that omega-3s might still be helpful for ALI, and going so far as to call for "a broad, bold research agenda" for the field of "pharmaconutrition" in general. I don't want to be a hater, but do we need any more trials like this one? Just don't enroll my Grandma, please ...

Rice TW et al. Enteral Omega-3 Fatty Acid, Y-Linolenic Acid, and Antioxidant Supplementation in Acute Lung Injury. JAMA ePub October 5, 2011. 

More commentary on Scott Aberegg's excellent Medical Evidence Blog.