Alleviation of Health Complaints Following Regular Consumption of Filtered Tap Water (AcalaQuell®) Is Independent from Placebo Effects

Abstract

Recently, it was shown that regular consumption of a standardized amount of filtered tap water improved the self-reported physical complaints. However, since individuals were fully aware of the type of water they consumed it was unclear to what extent this effect was ascribable to placebo effects. This paper tests the effectiveness of an in-home water filter system (AcalaQuell®) which was compared with a sham water filter containing no significant filter ingredients. Both filters were concealed, and participants knew that the probability to receive the clinically proven filter was 50 percent. There were large differences between the two groups (d = 0.7 < d < 2). For individual-specific complaints, the reduction was 38 percent for the filtered water group while the reduction in the placebo group was about 8 percent. Subjective health complaints are considerably reduced after daily intake of AcalaQuell®-filtered tap water during a three-week administration period. This effect is specific and independent from placebo effects.