Supplements Have No Impact After Lung Injury

Fatty acids could be harmful instead of helpful

(RxWiki News) Patients who suffered a lung injury, such as from pneumonia or sepsis, and received dietary supplements including omega-3 fatty acids were on a ventilator and in the ICU longer and had a small increase in the rate of death.

Previous studies had indicated that patients who'd suffered an acute lung injury (ALI) had lower levels of certain omega-3 fatty acids and gamma-linolenic acid (GLA), an omega-6 fatty acid. Researchers proposed that giving patients these dietary supplements would improve the patients' ability to recover. The results of the clinical studies showed otherwise.

"Fatty acid supplements may not offer benefits for acute lung injury."

Todd W. Rice, M.D., of Vanderbilt University School of Medicine, and colleagues conducted a study to examine the effects of supplementation of omega-3 fatty acids, GLA and antioxidants on clinical outcomes in patients with ALI in a phase 3 trial. Previous research had indicated these supplements might keep in check the body's inflammation response to the lung injury as well as improve oxygenation and patient outcomes. The scope of that research, however, was limited.

The researchers theorized that giving ALI patients a large dose of the supplements twice daily would increase the ratio of omega-3 to omega-6 fatty acids, reduce inflammation and improve certain outcomes. The study was a randomized, placebo-controlled, multicenter trial conducted from January 2008 through February 2009. Some 270 adults at 44 hospitals who were within 48 hours of developing an ALI and required mechanical ventilation were included in the study (143 in the supplement group and 129 in the control group).

The supplement dose consisted of two types of omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), along with GLA and antioxidants. The control group was treated with isocaloric control, meaning they received an equal amount of nutrition from proteins, carbohydrates and fats. The primary measured outcome was the number of ventilator-free days within 28 days of the study's start.

The study was stopped early for futility at the first interim analysis. While the supplement did raise blood levels of EPA eightfold compared to the control group, the researchers found the patients in the supplement group had fewer ventilator-free days by study day 28 compared to the control patients (14 days versus 17) and fewer days out of the ICU (14 days versus nearly roughly 17). Moreover, in the supplement group about 27% of the patients died before study day 60 or before being discharged from the hospital. In the control group, the rate was 16%.

When adjusted for certain mortality variables associated with ALI, the supplement group had a 25% mortality rate at 60 days compared to a nearly 18% rate for the control group, the study authors note.

In addition, the omega-3 supplement did not protect patients from hospital-acquired infections, nor did it improve the function of organs other than the lungs. In fact, patients receiving the omega-3 supplement had more frequent instances of gastrointestinal intolerance.

The authors write in the study that while twice-daily supplementation of omega-3 fatty acids, GLA and antioxidants does change the blood levels of omega-3 fatty acids, the supplementation does not improve clinical outcomes or biomarkers of inflammation in patients with ALI and "in fact may be harmful," the authors conclude.

The study appears in a recent issue of the Journal of the American Medical Association.

Review Date: 
October 5, 2011