A placebo’s true nature
There is a serious misconception put forth in the letter from William Davis (Feedback, SN: 5/22/10, p. 31). The placebos used for placebo-controlled, double-blind studies of pharmaceuticals are not “sugar pills.” These placebos are made from the same inactive ingredients in the same proportions used to make the dosage form containing the drug under study. These inactive ingredients seldom include sugar(s). These are the ingredients that make the dosage form easy to handle (fillers), hold together as tablets (binders), dissolve quickly in the stomach (disintegrants), etc. In that sense, the ingredients are not “inert” as Davis calls them; they have very specific functions in the drug.
The purpose of a placebo-controlled study is to separate the effects, if any, of these ingredients in the body from those of the drug under study. Another purpose is to assess the effect, if any, of the psychological “placebo effect” that some patients exhibit due to an expectation of some effect from having taken the drug or placebo.
Gregory R. Daigneault, Director of Chemistry, Geneva Labs, Elkhorn, Wis.

No fear of science
I disagree with Glenn McGee (Comment, SN: 6/19/10, p. 32) that people in general are afraid of science or scientists. I am 71 and have met a lot of people over the years, and I have never met such a person. People are afraid of fraud, but everyone I meet loves science and real scientists.
Alan D. Arnold, Gansevoort, N.Y.

Burnt out on smell
After reading that nerves in the nose can transport soot as well as metals and other nanoparticles to the brain, where they do significant harm (“Destination brain,” SN: 5/22/10, p. 16), I wonder whether our ancestors began to lose some of their sense of smell just as they domesticated fire. Fewer olfactory cells might have limited brain damage from chronic exposure to smoke, especially in cold climates where fire was used to heat and cook inside shelters with poor ventilation.
Eric Seldner, Eatontown, N.J.

Measuring dementia care’s risk
The question to ask, after reading that spouses caring for a husband or wife who has dementia suffer a much higher risk of having the same problem (“Dementia care may boost risk,” SN: 6/19/10, p. 13), is whether the same is true of any long-term caretakers. Such a study should indicate whether the stress of a loved one having dementia and/or the shared environment might be causative factors.
Nelson Marans, Silver Spring, Md.