The Great Debate: Using Antioxidants During Chemotherapy

By Keith I. Block, MD

Last week’s blog discussed how two randomized controlled trials involving smokers helped fuel a years-old misperception that beta carotene is harmful to all cancer patients.  As I noted in that posting, this erroneous assumption generally paints all antioxidants with the same “don’t-use” brush, understandably prompting great concern among cancer patients.  This week’s blog will address the use of antioxidants for cancer patients, and hopefully, help alleviate those concerns.

Let’s start with how some of this erroneous information took hold and became the primary message from mainstream media.

Back in 2005, Isabelle Bairati, from the Quebec Research Center, published a study that received national – no, make that international – attention.  The message?  Antioxidant vitamins can speed up the development of cancer.  Soon, every media outlet was warning cancer patients to avoid all antioxidant vitamins.  And the findings of additional studies – that have not stood up under closer scrutiny – were also publicized, furthering this misinformation.  Then, in 2008 – to her credit – Isabelle Bairati came out and said “we got it wrong.”  She said that the only people in the study who were seeing their cancer return were smokers who refused to kick the habit while they were receiving radiation therapy or chemotherapy.  Interestingly enough, not a single mainstream newspaper picked up this part of the story!  And the erroneous messaging continued its move forward.

If you’ve been following this blog, you’re already aware that a selective, individualized supplement regimen is part of the Block Center’s comprehensive, integrative approach to cancer treatment.  Over the last several years, the unrelenting warnings from the media have prompted questions and concerns from our patients, and in 2006 my research staff and I decided it was time to conduct a study of our own.  In conjunction with Robert Newman, PhD, then Professor of Cancer Medicine at M. D. Anderson Cancer Center, my research team and I performed a systematic review of clinical studies on the use of antioxidants during chemotherapy.  The results were published in the May, 2007 issue of the peer-reviewed journal Cancer Treatment Reviews (http://tinyurl.com/y9jrpa9) and in the September 2008 issue of the International Journal of Cancer (http://tinyurl.com/ycv63mp).  Our findings demonstrated that there is no scientific support for the blanket objection to using antioxidants during chemotherapy and, in fact, the use of antioxidants combined with chemotherapy may confer significant benefit.  Yet in spite of our findings being published in two very well respected medical journals, they received little media attention.

Among the findings:

• All of the studies that included survival data showed similar or better survival rates for the antioxidant group than the control group.
• None of the trials supported the theory that antioxidant supplements diminish the effectiveness of chemotherapy treatments.
• All but one of the studies that reported treatment response showed similar or better response in the antioxidant group than in the control group.
• 15 of 17 trials that assessed chemotherapy toxicities, including diarrhea, weight loss, nerve damage and low blood counts, concluded that the antioxidant group suffered similar or lower rates of these side effects than the control group.

Most importantly, when combining antioxidants with chemotherapy, the existing evidence strongly favors improved treatment tolerance, with a reduction in side effects.  In fact, it may help patients avoid having to cut back on their chemotherapy dosing, interrupt scheduled treatments, or abandon treatment altogether.  This in turn, is likely to favorably impact treatment outcomes.  It also demonstrates no significant interference.  In fact a considerable amount of evidence suggests the combination improves treatment efficacy.  That said, it is important to acknowledge that there is a more conservative position.  There are some patients who may prefer to avoid antioxidants during chemotherapy based on results of test-tube studies, and this is a defensible conservative position for those who are receiving initial or “curative” chemo regimens.  This argument carries less weight, though, in patients who are having difficulty tolerating chemo or who are being treated for cancers that recurred despite previous chemotherapy.

The Bottom Line:

At the Block Center, I have always advised our patients that supplements are only as good as the dietary foundation they stand on.  As I’ve said before (it bears repeating!), a supplement program, by definition, should be a booster to a healthy diet.  It should never be a substitute for a healthy diet.  When judiciously used as part of a full integrative treatment program for patients battling cancer or hoping to prevent a recurrence, selective regimens can be of significant value.  I encourage you to discuss any supplements and vitamins you are taking with your healthcare practitioner, not only to make sure they are right for you, but to help avoid any potential interactions with medications you may be taking.  Of course, quality will vary not only from brand to brand, but if a company manufactures multiple supplements, not all of them will necessarily pass independent testing.  Unless your practitioner formulates and tests on their own, it may be useful to utilize a website such as www.consumerlabs.com, which does independent testing of supplements for quality and purity.  Keep in mind, most supplements were designed for general health.  You are probably looking for something that better fits with your particular needs.  And when it comes to cancer treatment or prevention, the need for a personalized program is a must.

Comments

[Kristy Russ, BScPharm]

I agree fully. The problem with medical science studies is that they try to treat nutrients like pharmaceuticals and give people just one antioxidant or vitamin to see what the result is. Normally, that's good science, but antioxidants and other nutrients work synergistically, meaning they help each other work. So you just don't get the results you're looking for when you take just one (& sometimes it's harmful- like the beta-carotene in smokers study).

[Philip Liberman]

What about use of antioxidants during radiation therapy? My radiation oncologist said no. He says that the free radicals generated during radiation therapy are needed to damage the cancer cells and we don't want to do anything to inhibit that process. What do you think?

[stage iv lung cancer]

I have heard several news about antioxidants combined with chemotherapy treatment. However, I have not heard of any successful experiences from patients who have undergone chemotherapy with the antioxidant. But since, you mentioned that there was a study done on this, I will be searching for more information about it. Thanks for sharing this.

[Antioxidants]

It's worth checking out Vitamin B17 (amygdalin)..found in apricot kernels, cashews, bitter almonds, strawberries and apple pips. Studies are suggesting that this could be an alternative or an addition to chemo treatment.

[Veggie_1]

That part about the healthy diet sounds good. It seems the natural anti-oxidants in a plant-based food regimen will provide plenty of accelerant for the regeneration process. You would know better than I. If true, why would a supplement even be needed?