When is a placebo not a placebo? The answer to that question surprised a group of researchers who poured over the details from 150 clinical trials.
In a new study in the Annals of Internal Medicine, the researchers said that in the vast majority of cases, developers never disclose what they put in the phony therapy, which is supposed to be made up of harmless materials. But in the few cases when researchers did find the ingredients, they amazingly concluded that researchers may have hurt as well as helped the chances of their experimental therapies.
Case in point: In one study "olive oil and corn oil have been used as the placebo in trials of cholesterol-lowering drugs. This may lead to an understatement of drug benefit: The monounsaturated and polyunsaturated fatty acids of these 'placebos,' and their antioxidant and anti-inflammatory effects, can reduce lipid levels and heart disease."
Next case: A study of a new therapy for cancer patients suffering from anorexia used a placebo which included lactose. As the cancer patients faced a higher risk of lactose intolerance, the sham pill may have spurred side effects that made the experimental drug look better in comparison.
The authors say they aren't asking to find the perfect placebo. They just want researchers to spell out exactly what goes in the placebo, rather than leaving regulators blind to some intended, as well as unintended, consequences.
"We've been trained to associate placebos with being inert," lead researcher Dr. Beatrice Golomb of the University of California, San Diego, told Reuters Health. "But there isn't evidence that anything is truly physiologically inert."