Manuka Honey Has the Potential to Reduce Breast Cancer Tumor Growth, According to a New Study

If you love a spot of honey in your tea, on your granola, or just a spoonful on its own, researchers from the UCLA Health Jonsson Comprehensive Cancer Center have some potentially excellent news for you. 

Over the summer, the researchers published a new study in the journal Nutrients showing that Manuka honey could have the potential to be used as an alternative option for breast cancer prevention and treatment. 

As UCLA Health explained, the study showed that Manuka honey was particularly powerful "for estrogen receptor (ER)-positive breast cancer," which is the most common subtype of breast cancer, accounting for up to 80% of "all breast cancer cases." 

As the researchers wrote in the study, Manuka honey is a "monofloral honey that is produced from the nectar collected by honey bees when they pollinate the Manuka tea tree," which was once unique to New Zealand and parts of Australia, but now is produced in regions across the world.

While this particular kind of honey has already long been known to "exhibit antimicrobial, antioxidant, and tissue-protective/healing activities," the team also found that it is "rich in flavonoids, phytochemicals, complex carbohydrates, vitamins, amino acids, and minerals" and "contains other specific phytochemical factors that may potentiate its biological activity," including natural phytoestrogens, which are not found in other forms of honey. 

“Manuka honey has a number of unique nutrients and bioactive compounds that likely contribute to its health benefits as a ‘nutraceutical,’” Richard Pietras, a man whose laundry list of titles includes MD, PhD, professor of medicine in the Division of Hematology-Oncology at the David Geffen School of Medicine at the University of California, Los Angeles, and the Jonsson Comprehensive Cancer Center, director of the Stiles Program in Integrative Oncology, and senior author of this study, shared with Medical News Today.

“As we referenced in the published manuscript, there were a number of traditional, anecdotal, and preclinical reports on the anti-tumor effects of Manuka honey, which was also described as possessing antioxidant and wound-healing properties," Pietras said. "This collection of information precipitated our interest in pursuing the antitumor efficacy of Manuka honey in more formal experimental models of this disease."

So, the team used both mouse and breast cancer cell models to do just that, by administering human breast cancer cell lines (MCF-7 cells) to under the skin of 6-week-old female nude mice, allowing the tumors to grow to 50–80 mm. They then treated the tumors with Manuka honey orally twice daily for two weeks and daily for the remainder of the study (42 days total). And they found that in those mouse and ER-positive cells, Manuka honey caused an 84% tumor growth reduction — all without negatively impacting healthy cells or negative side effects. Additionally, the team noted that the more Manuka honey was administered, the greater the reduction in cancer cell growth.

“It is important to know the dose of a drug that does not cause unacceptable side effects," Pietras said. "Our purpose was to determine safe levels of Manuka honey dosing. Further work will be needed to determine the (maximum tolerated dose) in vivo for optimal and safe anti-tumor action.”

The team also found that the honey helped reduce levels of signaling pathways, which are typically enhanced in cancer. UCLA Health explained, these pathways usually "induce tumor cell proliferation, growth, and metastasis. Researchers theorize that one of the mechanisms of action of Manuka honey is to block estrogen receptors, making it potentially effective as a nutraceutical against hormone-sensitive breast cancer."

But it's important to note that these preliminary experiments were conducted on mice, and they need to be trialed on humans to see what effect it really has.

Still, Dr. Diana Marquez-Garban, associate professor of medicine at the David Geffen School of Medicine at UCLA and first author on the study, noted that  “The findings provide hope for the development of a natural, less toxic alternative to traditional chemotherapy. 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.”

And if you're going to incorporate Maunuka into your daily routine after reading this, Monique Richard, a registered dietitian nutritionist and owner of Nutrition-In-Sight, told Medical News Today, sure, go for it, but there's "no need to go as wild as Winne-the-Pooh would with a jar of Manuka honey," and added, "keep in mind that quality, source, and authenticity are paramount to reaping the benefits of this particular honey."