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Antioxidants may detract from effectiveness of 5-FU

Posts: 1956
Joined: Oct 2009


(I;ve read only the abstract and discussion part and just saw my onc last Wed;think i'll relay this to her office Mon)

annalexandria's picture
Posts: 2573
Joined: Oct 2011

my oncologist said not to take any anti-oxidants.  So definitely worth checking into, I think.

thxmiker's picture
Posts: 1282
Joined: Oct 2010

Dr. Lenz USC, told us to keep the Antioxidents high, but avoid Citrus antioxidents because they can feed the colon cancer.  This is not proven, just more evidence against Citrus AntiOxidents versus any other antioxidents while on Chemo.



Best Always,  mike

tanstaafl's picture
Posts: 1302
Joined: Oct 2010

from the Hormel Institute (most of the authors).  

1.  any paper that goes on and on about "antioxidants" is a political "science" paper.  Stick to the molecule(s) and dosages tested.  Generalizations like "antioxidants" are for politics and partisan advertisers.  FUD tactics keep a lot of people overpaying, and with results that underperform. 

2. low dose ascorbate and glutathione (NAC, N-acetylcysteine is a precursor) applied individually stop some oxidative kills of tumor cells, this is long known.   Loud, balleyhooed repetition of a failed flavor of experiment is often a horribilization-for-marketing paper, not new science.

3. combinations of  5FU, ascorbate, dehydroascorbate and many antioxidants, including NAC, can be hell on wheels tumor cell killers, totally the opposite result.  This is where testing, individual and larger clinical trials, can get interesting.

4. both in vitro experiments and clonal cell lines (rather than insitu or original tissue) can radically change results.

My wife was originally predicted to be dead, on average, over 2 years ago, presuming full courses of FOLFOX-avastin and FOLFIRI-erbitux. I do understand the basis of the oncologist's prediction, I've read *a lot* of papers.  As it turned out, she was originally blessed with mets at multiple sites and all the common fatal biomarkers, somewhat worse than the average mCRC... So some things needed to change.  We've been very naughty.  She still hasn't had any FOLFOX, FOLFIRI, avastin or erbitux.  She has had a lot of oral UFT (5FU precursor) and cheap foreign generics like cimetidine, with a boatload of carefully selected "antioxidants" and vitamins everyday.  [Note:  this is not a recommendation for ordinary do-it-yourself either.  I suggest experienced professional help with any CAM and nutrients]

Caveat lector. 

abrub's picture
Posts: 2178
Joined: Mar 2010

Anti-oxidants counteract the benefits of chemo.  Chemo and radiation try to oxidize cancer cells; taking anti-oxidants works against that.  Antioxidants are beneficial when you are not in treatment; eg:  chemo or radiation.

From Memorial Sloan Kettering Cancer Center - Integrative medicine:  http://www.mskcc.org/cancer-care/integrative-medicine/multimedia/herbs-botanicals-and-supplements-during-treatment

Annabelle41415's picture
Posts: 6722
Joined: Feb 2009

Yes that is exactly what my doctor told me.  Take nothing unless cleared by her.  One thing she did tell me to take was Vitamin B6.  It's always good to check with your doctor before taking anything.


tanstaafl's picture
Posts: 1302
Joined: Oct 2010

I don't mean for this to devolve.   The word "antioxidant" is very poor terminology for cancer treatments, it is overly broad and greatly  nonspecific.  It sweeps good and bad candidates into one bin, out the door, and overlooks many important chemical characteristics. 

Many here have had an antioxidant vitamin with their 5FU and consider it beneficial, even essential to their chemo's success.  This antioxidant is folinic acid aka leucovorin.  The common commercial vitamin form, folic acid, crashes and burns for 5FU application.  Even though folic acid has less antioxidant characteristic.

Reading many medical/science papers and patents, it turns out that are other specific nutrient molecules that are also antioxidants and that appear to improve 5FU performance. In 10-25 years, some antioxidant molecules may be better recognized in conventional medical practice too.   The financial pathway for such work is presently perverse and largely unfunded.

I don't close my eyes on these areas because I know they contain extra chances to stay alive with better quality of life.  It bothers me greatly to see others close their eyes on these subjects that might have made critical differences early on.  It bothers me even more when medical biases actually interfere with my wife's treatment or supplies, despite better information.   

I consult medical professionals for their specific expertise and hard information.  Oncologists have a repretoire of known chemo that works best for them.  That is their skillset. Outside that skillset, their expertise may become nonexistant.  Sending a plumber to do your electrical work may have problems.   When oncologists say nutrient antioxidants don't work, a better statement would be they don't know what specific or targeted techniques do work.  I often prefer to consult the MD/PhD experimental and clinical papers myself to avoid perfunctory conclusions.

Ultimately, specific molecular combinations and techniques are beneficial or incompatible.  Small changes can and do make polar differences in their result.  This is an area where medicine frequently fails technically and greatly err with generalizations like "antioxidants are incompatible".  They would better serve patients with more precise statements like "gerbils on FOLFOX 6 had an additional 1% rate of vomit with 2-5 mg of xxxxx added alone." A truthful "I don't know" would be helpful, too.

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