It did so in a sophisticated manner that even resulted in the occasional triggering of natural cell death, or apoptosis, a mechanism that's bypassed as a malignant cell becomes cancerous.

Manuka honey is made by bees that feed on the nectar of the manuka tree from New Zealand and coastal Australia. This member of the Myrtle family is a cousin to other plants that yield powerful medicinal products like clove, allspice, and eucalyptus.

In a study published in the journal Nutrients, investigators at the UC Los Angeles Health Jonsson Comprehensive Cancer Center found that Manuka honey significantly reduced tumor growth in mice with ER-positive breast cancer cells by 84% without affecting normal breast cells or causing major side effects.

ER-positive breast cancer makes up around 60-70% of all breast cancer cases in a given year.

It's thought that Manuka honey is unique compared to all other commercially produced kinds of honey because of its unique chemical composition. Manuka honey has been found to be antibacterial—and not just for the bacteria a parent worries about when their child scrapes their knee—but of the kinds that cause the infections typical in cystic fibrosis patients. 

"The findings provide hope for [the] development of a natural, less toxic alternative to traditional chemotherapy," said Dr. Diana Márquez-Garbán, associate professor of medicine at UCLA, and the study's lead author.

"Although more research is necessary to fully understand the benefits of natural compounds in cancer therapy, this study establishes a strong foundation for further exploration in this area."