Researchers studying the metallic nanomaterials in eight commercially available dietary supplement drinks have found that the drinks changed the normal organization and significantly decreased the number of human intestinal microvilli—cell projections that help digest food—and that daily use, assuming release to sewer systems, where large percentages of nanomaterials are not efficiently removed, likely result in these substances making their way into surface water with the potential to adversely affect aquatic life. Robert Reed, et al., “Characterization of Nanomaterials in Metal Colloid- Containing Dietary Supplement Drinks and Assessment of Their Potential Interactions after Ingestion,” ACS Sustainable Chemistry & Engineering, June 2, 2014.

According to the study, the drinks, which claim to improve “human health and function for a variety of organs,” contained metal nanomaterials in the 1-100 mg/L concentration range. The researchers “investigated the interaction of NM s [nanomaterials] in the drinks with an in vitro cell system that faithfully mimics human intestinal cells [and] found that the number of microvilli decreased relative to untreated controls for all drinks.” They also studied nanomaterial removal by biosolids in wastewater treatment plants using the nanomaterials in the supplement drinks and found “variable removal” rates ranging from 99 to 30 percent.