WEDNESDAY, Oct. 5 (HealthDay News) -- Nutritional supplements containing omega-3 fatty acids or antioxidants don't help patients with severe lung problems in the intensive care unit, a new study indicates.

According to the researchers, supplements may actually harm patients with pneumonia or sepsis. Patients given the supplements were on ventilators for more days, stayed in the intensive care unit (ICU) longer and were at a slightly higher risk of dying than their counterparts who didn't get supplements.

"Not only did it not help, but it may be worse," said Dr. Todd W. Rice, lead author of a paper published online Oct. 5 in the Journal of the American Medical Association, to coincide with a presentation at the European Society of Intensive Care Medicine meeting in Berlin.

The trial was stopped early because the results were so disappointing.

"Pharmaconutrition" has attracted increasing interest in recent years.

"The field of nutritional supplementation for critical-care patients is growing. Just like for community-dwelling persons, the hypothesis is that what you eat could affect your outcome when you're seriously ill," said Dr. Deborah J. Cook, author of an editorial accompanying the study and academic chair of critical care medicine at McMaster University in Hamilton, Ontario.

The science behind the idea is that nutritional supplements containing omega-3 fatty acids (found in fish), linolenic acid and antioxidants could quell the inflammation associated with acute lung injuries.

Three earlier, albeit smaller, studies had presented promising data, leading up to the current study, said by the researchers to be the largest undertaken to date.

The trial was supposed to enroll 1,000 patients, but was halted after results came in on only 272 patients.

All patients were in the ICU on ventilators because of lung problems and had been randomly assigned to receive nutritional supplements twice a day or simply nutrition without the supplements through their tube feedings.

Although the supplements did increase fatty acid levels in the blood (they didn't change in the control group), they didn't improve anything else.

Patients receiving the twice-daily supplements were on ventilators longer (14 days vs. 10.8 for the control arm), stayed in the ICU longer (14 days vs. 11.3 days) and had more days of diarrhea.

They were also more likely to die. After 60 days, 26.6 people receiving omega-3 had died vs. 16.3 percent in the control group. However, the difference was not considered to be clinically significant.

There were some differences between this study and the previous ones that may help explain the different results.

Unlike previous studies, in this trial regular nutrition was delivered separately from the supplements and in two doses as opposed to a continuous feed.

"We thought it would be a benefit for patients who couldn't tolerate full feeding," explained Rice, an assistant professor of medicine at Vanderbilt University in Nashville, Tenn.

And previous control mixes were high in fat, whereas this one was mostly carbohydrates.

But it's unclear at this point if these differences actually can explain the divergent results, if there are other factors at play or if nutritional supplements really don't hold out any hope for these critically ill patients.

"The next logical step," said Rice, "is to look at the different components, fatty acids, carbohydrates and protein, to see if any of them make a difference in improving outcomes."

Adding nutritional supplements is not "the standard of care" at this time, said Dr. Hormoz Ashtyani, director of pulmonary critical care and sleep medicine at Hackensack University Medical Center in New Jersey.

"Now we have a couple of smaller papers that say this helps somewhat and a bigger one that says it doesn't, so this has to go on and be investigated further," Ashtyani said. "This paper is a caution to those who were using it on an off-label basis, who were being a little bit avant garde, that maybe they shouldn't be doing this."

More information

The U.S. National Library of Medicine has more on critical care.