I am reposting a reply to the Vitamin B1 thread as I noticed a search on HealthUnlocked for Benfotiamine doesn't list the thread for Vitamin B1 and the information I posted doesn't fit in one reply.
I'm not giving medical advice but I know a lot of people here are open to trying things and watch if there's a change in their PSA kinetics. Things like Sulforphane (broccoli seed extract), melatonin, green tea extract (ECGC), curcumin, etc etc etc. These and others have some study data and anecdotal reports but it appears Benfotiamine use relating to cancer has relatively much less data (especially recent data) compared to these other more well-known substances, and I can find no anecdotal reports from Prostate Cancer patients.
To summarize what the data so far shows (read all the info yourself to confirm), low to medium doses of Thiamine (Vitamin B1) can possible accelerate cancer progression. However all data I have seen so far shows that high-dose Thiamine, especial the lyophilic form (fat-soluble) Benfotiamine, has anti-cancer effects. Here are is all the published data I've found that appears relevant starting with the most compelling evidence first.
Anyone considering trying this should probably read all the information on Examine.com to understand all the different possible effects:
examine.com/supplements/vit...
Also Very Well Health.
"A safety and tolerability study reported that the rate of adverse effects for short-term benfotiamine use in young, healthy volunteers was similar to that for placebo."
verywellhealth.com/benfotia...
dovepress.com/safety-tolera...
More specific studies related to cancer (some already referenced previous but including them for reader convenience):
> Thiamine mimetics sulbutiamine and benfotiamine as a nutraceutical approach to anticancer therapy
"The chemotherapeutic effectiveness of benfotiamine translated in vivo where its administration reduced tumor growth in a subcutaneous xenograft model of HCT 116 cells. To our knowledge, this is the first in vivo evidence for the anticancer effect of a commercially available thiamine analog. Highlighting the therapeutic safety of benfotiamine, no systemic toxicity was observed following bolus pharmacologic doses (250 mg/kg) administered via IP injection every second day. This supports the tolerability of daily benfotiamine administration (600–900 mg/day) that has previously been demonstrated in clinical trials for diabetic nephropathy"
sciencedirect.com/science/a...
> High Dose Vitamin B1 Reduces Proliferation in Cancer Cell Lines Analogous to Dichloroacetate
"Our findings suggest that high dose thiamine reduces cancer cell proliferation by a mechanism similar to that described for dichloroacetate."
ncbi.nlm.nih.gov/pmc/articl...
> The effect of thiamine supplementation on tumour proliferation. A metabolic control analysis study
"Thiamine supplementation in doses between 12.5 and 250 times the recommended dietary allowance (RDA) for mice were administered starting on day four of tumour inoculation. We observed a high stimulatory effect on tumour growth of 164% compared to controls at a thiamine dose of 25 times the RDA. This growth stimulatory effect was predicted on the basis of correction of the pre-existing level of thiamine deficiency (42%), as assayed by the cofactor/enzyme ratio. Interestingly, at very high overdoses of thiamine, approximately 2500 times the RDA, thiamine supplementation had the opposite effect and caused 10% inhibition of tumour growth. This effect was heightened, resulting in a 36% decrease, when thiamine supplementation was administered from the 7th day prior to tumour inoculation. Our results show that thiamine supplementation sufficient to correct existing thiamine deficiency stimulates tumour proliferation as predicted by MCA. The tumour inhibitory effect at high doses of thiamine is unexplained and merits further study."
(10% and 36% don't seem very impressive [to me] though)
pubmed.ncbi.nlm.nih.gov/114...
The Effects of Thiamine on Breast Cancer Cells
"Conclusions: The treatment of MCF7 breast cancer cells with 1 μg/mL and 2 μg/mL of thiamine for 24 h significantly reduced their proliferation. This reduction is associated with a reduction in glycolysis and activation of the PDH complex in breast cancer cells."
ncbi.nlm.nih.gov/pmc/articl...
> Prostatic acid phosphatase (PAP) is required for the antinociceptive effects of thiamine and benfotiamine
(my main takeway on this one is that PAP is increased in men with Prostate Cancer - it is unclear to me if this is to a lesser degree though after prostatectomy?)
pubmed.ncbi.nlm.nih.gov/231...
Bioavailability assessment of the lipophilic benfotiamine as compared to a water-soluble thiamin derivative
"Biokinetic data, measured as area under the curve and maximal concentration in plasma and hemolysate after ingestion, demonstrated a significantly improved bioavailability from the lipophilic derivative despite an ingested dose of only 40% as compared with the water-soluble salt. A superior cellular efficacy of benfotiamine was also concluded from the short-term stimulation of the thiamin-dependent transketolase activity in erythrocytes."
pubmed.ncbi.nlm.nih.gov/177...
Examining the full publication, by my math, 27 mg (not 40) Benfotiamine is equivalent to 100 mg Thiamine supplement based on the Plasma AUC numbers. Even greater difference based on Hemosylate AUC)
sci-hub.se/https://doi.org/...
> Pharmacokinetic study of benfotiamine and the bioavailability assessment compared to thiamine hydrochloride
"The transformation process of benfotiamine to thiamine produced large amount of hippuric acid. No accumulation of hippuric acid was observed after multiple-dose of benfotiamine."
pubmed.ncbi.nlm.nih.gov/243...
> Japanese Leukemia Patient
I did manage to find one article involving Benfotiamine use in a leukemia patient which is quite interesting.
ncbi.nlm.nih.gov/pmc/articl...
"We recently reported that in a patient with AML who was ineligible for standard chemotherapy due to his advanced age and because he had dementia, chronic renal disease and angina pectoris, the number of peripheral blasts decreased dramatically after receiving monotherapy with oral benfotiamine that was being given to treat low levels of vitamin B1. In that particular patient, leukemia cells became virtually undetectable by 20 days after the initiation of benfotiamine therapy without causing tumor lysis syndrome (Sugimori 2013: 75th annual meeting JSH, PS-2-35). Although the patient eventually died due to leukemia regrowth, we hypothesized that a relation may exist between benfotiamine intake and the transient leukemia remission observed in that patient. In the present study, we report evidences indicating that benfotiamine may have therapeutic potential against AML. Our mechanistic studies suggest that benfotiamine inhibits leukemic cell growth by triggering paraptosis cell death."
* My Personal Opinion *
Based on the data, it appears high-dose Benfotiamine is safe as multiple studies used doses in the range of 300-900mg and at least one study with 1,200 mg and I saw a reference to using 4,000 mg. This is not to say there are potential side effects related to stomach issues or rash but there's no indication of anything very serious.
One study mentions up to 75 times the RDA can promote cancer another referencing a mouse RDA that 2500 times was needed. This is where the challenge is, determine the dosage that is effective. Until a trial is run or we start seeing anecdotal reports this is going to be a best guess.
I could have sworn I read a paper/study that made the conclusion that a minimum of 200 or 300 mg was needed. I think that was Thiamine. That would be 166 to 250 times the RDA. I think to be conservative one might assume you need at least 500 times the human male RDA. That would be 600 mg of the water soluble form which would be approximately equivalent to (even using the very conservative 40% bioavailability figure) 240 mg Benfotiamine.
Yet we have people commonly taking 600-900 mg Benfotiamine for other purposes. So to me, as long as there were no side effect, to error on the side of caution to make sure the dose was high enough, I'd take 600-1000 mg a day Benfotiamine probably divided into two doses. 300-600 has been used for a modest decrease in pain associated with Diabetic Polyneuropathy.
900mg Benfotiamine = at least the equiv of 2,250mg water-soluble Thiamine = 1,875 times the RDA - pretty close to the study citing the 2500 times mouse RDA.
Would someone out there do a human subject study regarding Prostate Cancer! I guess for now, it's up to any of us to try it if they choose. No MO is going to be able to give any clear answer I would suspect aside from the general high-dose safety profile if they are up on Vitamin B.
While it might not be a silver bullet, anything that helps contribute to slowing cancer progression that has not toxicity would be a welcome tool in the toolbox.
