Talk about conflicting data! According to a number of researchers, the amino acid, L-glutamine, may be bad for multiple myeloma patients. Yet taken in large enough doses it clearly helps many control their peripheral neuropathy.
Danny Parker and I have warned our readers repeatedly about the risks of taking L-glutamine (most shorten it to “glutamine”) supplements. Here’s an excerpt from a post I wrote about food and supplements that myeloma patients should avoid last summer:
Again, Danny researched this one, too. Over 2000 readers checked-out his reservations about this amino acid that is–ironically–often prescribed to help minimize peripheral neuropathy (PN) symptoms:
Another supplement to avoid, especially before, during and immediately after a transplant: L-Glutamine
Like several others on the list, this one is controversial. To me, if it can help my PN, it’s probably worth the risk to take it. But I dropped it from my anti-PN supplement assortment and didn’t notice any difference, so I never resumed taking it…
Fair enough. But I learned a lot more about glutamine at last year’s ASH meetings in New Orleans. I interviewed Cleveland Clinic’s Beth Faiman about a study she helped get started, using glutamine to help minimize PN. Apparently glutamine was making a significant difference in most of the patients almost overnight!
What was I doing wrong? Why didn’t it seem to make any difference for me? Dosing! I was taking one 500 mg capsule in the morning and another at night. The Cleveland Clinic study used 8 gm daily. That’s 8 times as much!
Unfortunately, the trial was cancelled too soon to record any definitive data; not because it wasn’t working, but because staff was having trouble standardizing the dosing.
Here’s a post I wrote announcing the trial before I met with Beth at ASH:
I specifically asked Beth about the fact that myeloma cells had gobbled glutamine up like candy in laboratory based (preclinical) trials. She responded that her patients were carefully monitored, and glutamine supplementation had no measurable effect on their myeloma. Beth added that staff at Cleveland Clinic had been recommending use of glutamine to help improve PN symptoms in their myeloma patients for years with no noticeable change in their numbers.
Of course, how would one really know if glutamine was enabling a patient’s myeloma? To me it’s like curcumin. There may be a benefit, but it’s subtle and difficult to quantify.
NOT SO FAST! Ready to take glutamine off your contraindicated supplement list? Some researchers must think it’s a problem. Last week suzierose (Myeloma Cinderella) forwarded me information about a clinical trial using a drug (CB-839) designed to block cancer cell’s ability to utilize glutaminase, a key enzyme in glutamine:
Study of the Glutaminase Inhibitor CB-839 in Hematological Tumors
Many tumor cells, in contrast to normal cells, have been shown to require the amino acid glutamine to produce energy for growth and survival. To exploit the dependence of tumors on glutamine, CB-839, a potent and selective inhibitor of the first enzyme in glutamine utilization, glutaminase, will be tested in this Phase 1 study in patients with advanced hematologic malignancies.
This study is an open-label Phase 1 evaluation of CB-839 in subjects with hematological tumors. Patients will receive CB-839 capsules orally three times daily. The study will be conducted in 2 parts. Part 1 is a dose escalation study to identify the recommended Phase 2 dose. In Part 2, all patients will receive the recommended Phase 2 dose. Both Parts 1 and 2 will enroll patients with advanced and/or treatment-refractory Non-Hodgkin’s Lymphoma (NHL), Multiple Myeloma (MM), or Waldenström’s macroglobulinemia (WM). All patients will be assessed for safety, pharmacokinetics (plasma concentration of drug), pharmacodynamics (inhibition of glutaminase), biomarkers (biochemical markers that may predict responsiveness in later studies), and tumor response.
Here’s a link to to the trial specs on ClinicalTrials.gov:
That’s an eye-opener! The fact glutamine was involved was a coincidence; suzierose kindly sent me the information after learning the study didn’t require a 1.0 M-spike minimum like so many others with criteria that excluded me from participating. Thanks, Myeloma Cinderella! Not sure I’ll become part of the study, but it sure helped make Danny’s point about avoiding glutamine supplements.
The million dollar questions: Does ingesting glutamine help feed our myeloma? Or does digestion in our gut change the chemistry enough to minimize any pro myeloma effects?
My recommendation? If I was unable to control my PN symptoms using Gabapentin (neurontin), oxycodone (which I take anyway for bone pain) and vitamin B, I would consider using large doses of glutamine to help. Several readers swear by it, and they probably would benefit from taking more.
Glad we cleared that up!
Feel good and keep smiling! Pat