Power of Placebo Effect

Results of a new study on omega-3 fatty acid show a surprising placebo effect. Researcher Dawn Hershman, leader of the Breast Cancer Program at Herbert Irving Comprehensive Cancer Center in New York, says the study’s goal was to determine whether omega-3 showed any effectiveness at relieving painful arthralgia in women taking aromatase inhibitors. She found that participants who received either the supplement or a placebo had a reduction in symptoms.

Omega-3 supplements have antiinflammatory effects that can decrease arthralgia, the musculoskeletal pain that often causes women to discontinue taking aromatase inhibitors. A quarter of breast cancer survivors report using the supplement. In the study, more than 250 women were randomized to take omega-3 or a placebo for 12 weeks. The results showed an improvement in arthralgia for 60 percent of all participants, suggesting that the omega-3 or the placebo had a benefit.

“The magnitude of the change in the omega-3 [group] was similar to other interventions,” Hershman says. “What was unusual about our result was that over 55 percent of the patients on the placebo arm had clinically significant improvement.”

Hershman said those involved in the study were surprised at the profound placebo effect. Researchers have concluded that either the placebo used (a combination of soybean and corn oils) had beneficial effects or that a large placebo effect should be expected when conducting trials for arthralgia.

Hershman is also investigating pharmaceutical treatments and acupuncture for arthralgia relief.