May 21 2007 post. For an overview of ellagic acid, see this Sloan Kettering page: http://tinyurl.com/2z33t5
I have not come across any studies specifically linking ellagic acid, or ellagitannins (the difference is explained below), to myeloma, but its anti-cancer properties are well-established, at least in vitro and in vivo on cells, rats and mice. I would like to mention that the University of Oslo is currently conducting a clinical trial on ellagic acid and other substances (quercetin, selenium, garlic extract, EGCG, etc.) for follicular lymphoma, Stage III/IV; see http://tinyurl.com/2q72ja This is the only clinical trial testing ellagic acid at present. Too bad.
The lack of human clinical studies does not discourage me. Ellagic acid is on my to-try list of supplements. This polyphenol can be found in raspberries and in berries in general, and also in pomegranates, walnuts and pecans. It has antioxidant, antibacterial and antiviral properties (aha!), and has been found to cause apoptosis of cancer cells (aha, again!). From what I have read, plants produce ellagic acid to ward off microbiological infection and pests such as aphids, which I find very appropriate since what is myeloma if not a pest?! According to the U.S. Department of Agriculture (http://tinyurl.com/2p9ms6): Plants produce ellagic acid and glucose to form ellagitannins, water-soluble compounds that are easier for people to absorb in their diets. This means small amounts of ellagitannins may be more effective in the human diet than large doses of ellagic acid.
See also the Washington Red Raspberry Commission report (http://tinyurl.com/3xnq9v), which provides information on the best variety of raspberry in terms of ellagic acid content: the Meeker variety. The report also tells us the following: "Ellagic acid acts as a scavenger to ‘bind’ cancer-causing chemicals, making them inactive. It inhibits the ability of other chemicals to cause mutations in bacteria. In addition, ellagic acid from red raspberries prevents binding of carcinogens to DNA, and reduces the incidence of cancer in cultured human cells exposed to carcinogens." How about that?! Keep in mind that this information is based on cells. Still ! The report also provides links to more than 100 references : http://tinyurl.com/2wru6y I haven’t checked all of them yet, but the interesting part for me was that the list goes back to the 1960s. Therefore, the cancer-ellagic acid studies are as old as I am. Almost! At any rate, this is a very useful website, with heaps of useful information about raspberries. Ohio State University (http://tinyurl.com/2tjpnq) published a study on the ellagic acid content of various berries, which concludes that the highest content of ellagic acid, at least in the Ohio plants, is in the leaves, not the fruit. It is also high in the seeds or in the unripe fruit.
Synergism between natural compounds. I recently read a fascinating 2005 abstract (http://tinyurl.com/28w747) on the synergistic interactions between polyphenols, specifically ellagic acid, quercetin and resveratrol, added to human leukaemia cells (MOLT-4): Results indicate that the anticarcinogenic potential of foods containing polyphenols may not be based on the effects of individual compounds, but may involve a synergistic enhancement of the anticancer effects. Well, well. A 2004 study (http://tinyurl.com/29s5lr) informs us that phytochemicals extracted from plants, including ellagic acid, resveratrol and curcumin have been shown to suppress cancer cell proliferation, inhibit growth factor signaling pathways, induce apoptosis, inhibit NF-kappaB, AP-1 and JAK-STAT activation pathways, inhibit angiogenesis, suppress the expression of anti-apoptotic proteins, inhibit cyclooxygenase-2. By the way, the last item, i.e. cyclooxygenase-2, is the infamous COX-2 enzyme, which is an independent predictor of poor outcome in myeloma (see: http://tinyurl.com/2lvw9t).
After reading these studies, my first thought was: put these compounds together in a bioavailable form, and cancer cells will have nowhere to hide. Of course, only human trials will show which compounds work well together and which do not. In the meantime, this summer I will certainly be eating a lot of raspberries!