Over four billion avocados were sold last year in the U.S. and for good reason – they’re so darn delicious and good for you too (wish you could say the same for doughnuts). Often called the world’s perfect food, avocados are high in fiber and packed with vitamins. Even the fat they contain is the healthy kind that’s associated with lower cholesterol levels and healthier hearts. As if the news couldn’t get any better, research published this week now suggests that a nutrient found in avocado can kill cancer stem cells – a cell type thought to be the source of a cancer’s unlimited growth and spread.
The study, reported in Cancer Research by a Canadian research team at the University of Waterloo, focuses on a particularly deadly form of blood cancer called acute myeloid leukemia (AML). Often striking adults over 65, AML has a poor prognosis with only 10% survival after five years for this age group.
The cancer is caused by rapid, abnormal growth of white blood cells in the bone marrow that eventually crowds out normal blood cells leading to a deterioration of vital functions of the blood like carrying oxygen to the body. Chemotherapy or bone marrow transplants are standard treatments but unfortunately, even when successful, a majority of AML patients will relapse.
Though they make up a tiny portion of the leukemia, cancer stem cells are thought to be the main culprits behind AML relapse due to their stem cell-like ability for unlimited growth. The research team identified a nutrient in avocados called avocatin B with the ability to kill AML cancer stem cells. The killing mechanism of avocatin B was pinpointed to its disruption of the mitochondria, the cell’s energy “factory”, in leukemia cells, which led to cell death. As senior author Professor Paul Spagnuolo points out in a university press release, this cancer killing property of avocatin B promises to have limited side effects:
“We’ve performed many rounds of testing to determine how this new drug works at a molecular level and confirmed that it targets [cancer] stem cells selectively, leaving healthy cells unharmed.”
Now, before you rush out to the grocery store and stock up on nothing but avocados, keep in mind this is a preliminary study in petri dishes. Extensive follow up studies will be required before testing in humans can begin. Also, it’s not clear if eating avocado or an avocado extract would be a sufficient method of delivering avocatin B to keep cancer stem cells at bay. It’s more likely that avocatin B would be purified and provided as a food nutrient drug or a so-called nutraceutical:
“Extracts are less refined. The contents of an extract can vary from plant to plant and year to year, depending on lots of factors – on the soil, the location, the amount of sunlight, the rain,” explains Spagnuolo. “Evaluating a nutraceutical as a potential clinical drug requires in-depth evaluation at the molecular level. This approach provides a clearer understanding of how the nutraceutical works, and it means we can reproduce the effects more accurately and consistently. This is critical to safely translating our lab work into a reliable drug that could be used in oncology clinics.”
I look forward to following this story in the months and years to come with the hope that families devastated by an AML diagnosis will have more treatment options.