Many drug trials involve a placebo, a sham drug whose results are compared with the results of the real medication. A placebo is supposed to contain a harmless substance, such as sugar or vegetable oil, which has no significant effect on the body. In [a new] study, researchers delved into 176 studies published in reputable medical journals ... from January 2008 to December 2009 to see if placebo contents were disclosed and if so, what they were. The study authors argue that placebo ingredients may not always be as inconsequential as some may think. They write: For instance, 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." Certain placebos, they add, may skew results in favor of the active drug. The researchers referenced a trial for a drug used to treat anorexia linked with cancer in which a lactose placebo was used. Since lactose intolerance is common among cancer patients, the fact that some suffered stomach problems from the placebo may have made the actual drug look more beneficial. "Perfect placebo is not the aim," they write, "rather, we seek to ensure that its composition is disclosed."