Water-generated negative air ions activate NK cell and inhibit carcinogenesis in mice

Negative ions are considered to have potential health benefits, but few studies have examined their effects in vivo. We studied water-generated negative ions (WNI) with respect to physical properties as well as immunologic activation and anti-tumor activity (inhibition of carcinogenesis and tumor growth) in mice. Electrically, generated negative ions (ENI) served as control. Water-generated negative ions had a long life, significantly enhanced the cytotoxic activity of natural killer cells, and significantly decreased the incidence of cancer and inhibited tumor growth. Anti-tumor effects were attributed to enhancement of natural killer cell activity. The mechanisms and applications of negative ions warrant further investigation.