Fish oil may harm lung injury patients

VANDERBILT (US) — Lung injury patients who were given a supplement of omega-3 fatty acids and antioxidants did not fare better, and in some cases fared worse, than those who did not receive the supplement.

A new study published in the Journal of the American Medical Association, reports that patients that received the supplements in their enteral nutrition experienced longer stays in intensive care, more days on a ventilator, and a slight increase in mortality than those that received omega-6 fatty acids and carbohydrates.

The findings run counter to previous research that suggested omega-3 fatty acids and antioxidants would improve outcomes in patients with acute lung injury (ALI), a disease process that occurs in patients who develop sepsis, trauma, aspiration, and other conditions and that causes the lungs to leak fluid. The condition leads to breathing difficulty that can require ventilator support.


“Your body puts fatty acids in the cell layer and then uses them to form inflammatory mediators. The mediators formed from omega-3 are much less inflammatory than omega-6 fatty acids; many think they are anti-inflammatory,” says Todd Rice, assistant professor of medicine at Vanderbilt University.

“We thought if we gave omega-3 fatty acids to patients with ALI they would make non-inflammatory, or less inflammatory, mediators that could decrease inflammation and possibly improve outcomes in these patients.”

The OMEGA study was a randomized, placebo-controlled, multicenter trial conducted at 44 hospitals in the National Heart, Lung, and Blood Institute (NHLBI) ARDS Clinical Trials Network from January 2008 through February 2009. Participants were 272 adults within 48 hours of developing ALI requiring mechanical ventilation whose physicians intended to start enteral nutrition.

The study didn’t find any benefit, and in fact there was some suggestion the patients who got the dietary supplement may have been worse off. The trial was stopped early because of futility.

Ventilator-dependent ICU patients are fed through a tube in the stomach continuously, but it’s never been fully understood what the best form of nutrition is or how often patients should receive it, Rice says.

“This study helps us to know that feeding fish oil isn’t beneficial and may be harmful. We still have questions of whether to provide formulations of feed that are less fat and more sugar or carbohydrates. There is work to be done there.”

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