Genotoxicity of human milk extracts and detection of DNA damage in exfoliated cells recovered from breast milk (vol 257, pg 319, 1999)

Genotoxic agents of environmental or dietary origin may play a role in brea st cancer initiation. The ability of extracts of human milk to cause mutati ons in S. typhimurium TA1538 and YG1019 and to induce micronuclei and DNA s trand breaks in MCL-5 cells was investigated. Twenty samples from different donors were analysed and of these, 6 were adjudged to produce a positive m utagenic response in one or both bacterial strains. The same samples also i nduced significant micronucleus formation in MCL-5 cells. In the comet assa y, 13/20 samples caused DNA strand breaks in MCL-5 cells. Viable exfoliated breast cells were recovered from fresh milk samples and the ability of mil k extracts to cause DNA damage in these cells was demonstrated. The results show that human milk can contain components capable of causing genotoxic d amage in test systems and in human breast cells, events that may be signifi cant in the initiation of breast cancer. (C) 1999 Academic Press.