Adding d-Mannose, stage 3 CRC adenocarcinoma, FOLFOX chemo

D-Mannose, as you probably know is a sugar closely related to glucose It is found in high concentrations in fruits such as cranberries. It is sold as a supplement since many people think it helps with UTIs by interfering with the growth of e coli. There are some recent studies and especially a January 2024 study done in China which Indicate oral administration of D-mannose dramatically inhibited angiogenesis and tumor growth in mice. Their findings reveal a previously unrecognized anti-tumor mechanism of D-mannose by destabilizing VEGFR2. This is a growth factor which cancers use to spread by creating new blood vessels. However these studies were only done in cell culture and in mice, I have not been able to find any published human studies. Taking this as a supplement probably won't hurt. The problem is you don't know the maximum amount you could take without it being a safety issue. Suggest you talk to your oncologist and ask the maximum amount of supplement can recommend

Hello @missycanary and welcome to Mayo Connect. We have had numerous Connect members discuss d-Monnose. Here is a link to many of those discussions. https://connect.mayoclinic.org/search/?search=d-Mannose

Please feel free to click on "Reply" if you see a post and you would like to ask a question or make a comment.

I also found an article on this product on the WebMD website. Here is a link to more information,
https://www.webmd.com/vitamins-and-supplements/d-mannose-uses-and-risks
Has your husband's oncologist recommended this to help prevent the UTIs?

I’m thinking it would be good, having had good results myself. We’re asking for use confirmation from them & also the oncology dietician. They are hesitant to confirm no interference with chemo, just not enough info, as they consider it to be a supplement.

@missycanary, unfortunately supplements are not regulated or as well tested as treatments. Have you considered discussing with an oncology pharmacist? What suggestions has the cancer team offered to help control the urinary tract infections?

I read online 1000 mgs a day.. Who knows for sure but I'm going to do 500mgs daily and see. It sounds promising to me.

@roywalton
An interesting recent clinical study
https://www.medscape.com/viewarticle/d-mannose-fails-prevent-urinary-tract-infections-women-2024a10008he

Thanks for this article..... For people who have cancer as I do you have a tendency to want to hang on to any possible solution..... I'm lucky to be able to depend on a great oncology team at Mayo Clinic

Thanks for all the input. I hope that testing will continue on this.

I mentioned to my oncologist that I had been taking d-mannose regularly for my bladder symptoms before I knew I had bladder cancer. He had a positive reaction and suggested I keep taking it. I had already read the study that showed it had an inhibitive effect on the growth of cancer cells, so I was happy that I had been taking it regularly in the year prior to diagnosis. I often wonder if it masked symptoms, since it does help my bladder stay more comfortable. I especially make sure I take it after chemo treatments. AZO also helps with pain, but causes me some nausea, but d-mannose only has had positive effects.

@bethcamp - As we discussed previously, D-Mannose is a simple sugar closely related to glucose, naturally found in fruits like cranberries, apples, and peaches. It’s commonly used to support urinary tract health by preventing bacteria from adhering to the bladder and urinary tract walls, potentially reducing infection risk. Some studies suggest D-Mannose may have an inhibitory effect on certain cancer cells, including bladder cancer, by interfering with their growth and adhesion, though research is still preliminary and not conclusive. It’s generally well-tolerated, with minimal side effects for most people, but its impact on masking bladder cancer symptoms isn’t well-documented and would require further investigation
It’s great to hear your oncologist was supportive of your D-Mannose use, especially given the study you mentioned about its potential to inhibit cancer cell growth. It’s understandable to wonder if it might have masked symptoms, as its soothing effect on the bladder could reduce discomfort. Continuing it post-chemo seems like a thoughtful choice, especially since you’ve experienced only positive effects. It’s also helpful to know AZO helps with pain but causes nausea for you—D-Mannose’s gentler profile sounds like a good fit. Have you discussed with your oncologist whether D-Mannose’s benefits might interact with your chemo or affect symptom monitoring? It could be worth exploring to ensure it aligns with your treatment plan.