In Introducing the Hunan Winged Bean (June/July 2007), we asked readers to write in about their experiences growing winged beans. In the following letter, internationally renowned herbal expert James A. Duke, Ph.D., discusses winged beans as a source for betulinic acid, a promising anti-cancer compound.
You asked for comments on your winged bean article. Very timely, as I was studying it as the best source of betulinic acid, an antimelanomic compound. While the following information does not prove that winged bean will help with melanoma, if I had melanoma (I don't), I'd have winged beans in my garden (I do), and in my diet. (Ironically, two of the young folks helping me get the winged bean into my Green Farmacy Garden this May are also melanoma survivors.)
The winged bean is so far the richest source of betulinic acid (at least in my USDA phytochemcial database) and betulinic acid is one of the most promising phytochemcials for melanoma.
Years ago, I remember getting all excited after reading in The New York Times that betulinic acid worked better on murine (rodent) melanomas than the drug most commonly used to treat melanoma. More recently and more specifically, we read, “Betulinic acid has proven to be the most effective antitumor agent among more than fifty natural lupanes.” (Tolstikova et al., 2006). After a week of reading on melanoma, I’ve decided that winged bean (shoots or roots, not seeds, though all are edible), though not well known analytically, is one of the more promising food farmaceuticals for melanoma.
Since poorly known analytically, there is not much more phytochemical evidence to recommend it. My analytical colleague, Dr. Peter Kaufman, University of Michigan, will be analyzing winged bean for the phytoestrogens daidzein and genistein, which also show anticancer activities that could be useful in melanoma. These estrogens are present in chickpea, faba bean and lentils (Duke, 2007). I suspect they’ll be found in winged bean, perhaps at lower levels.
It does take almost a leap of faith (often useful in desperate situations like late stages of melanoma) to hope that a food farmacy combo like winged bean, best source of betulinic acid, and milk thistle, unique source of silymarin, might be healthier and cheaper, if not as efficacious, as the chemotherapeutic dacarbazine (DTIC) and interferon (Web MD, 2007). Yes, I think they should be clinically compared. I stress whole herb, not isolated betulinic-acid and silymarin.
The stems and young shoots, also reportedly edible, are much better sources of the antimelanomic compound than the seeds. So I will be trying tender shoots stir fried, doubting that my growing season is long enough to flower and set seed.
James A. Duke, Ph.D.