While chemotherapy remains the mainstay of treatment for most types of cancer, there will be a need to improve what’s called the ‘therapeutic index’. Simply put this is a measure of the good a drug does versus the bad. Chemotherapy causes all kinds of toxic side effects while killing cancer cells, and generally it could kill more if given at a higher dose, but to do so ends up causes a lot more damage. One way of improving chemo is through the use of new generation drugs that target tumour cells rather than the indiscriminate slaughter of the older drugs.
Another way to do this is to find ways of protecting normal cells in some way and/or making cancer cells more susceptible to the effect of the existing chemo drugs. Can this be done safely? According to some researchers the answer is a qualified yes. And the magic drugs that can spare normal cells but make cancer cells more susceptible to chemo are…omega 3 fish oils. There is mounting evidence that omega 3 fish oils, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), can indeed work in this way.
A new paper ‘Selective sensitization of tumours to chemotherapy by marine derived lipids: A review’, published in the journal Cancer Treatment Reviews (abstract here: http://www.ncbi.nlm.nih.gov/pubmed/22850619), goes over the evidence from cell cultures, animal experiments and clinical trials. And there is a lot of evidence to go over. The authors summarise it quite nicely, showing that the positive effect is there across many tumour types (including breast, prostate, colon, lung, lymphomas and more), and across chemo types (nearly all of the main classes of chemotherapy drug are listed).
One very encouraging aspect of this story is the number of active clinical trials looking at this now. The pre-clinical results and first analyses from those human trials that have taken place have all been positive. And when you factor in the other positive effects of EPA and DHA, such as helping to cope with stress (http://www.anticancer.org.uk/2012/02/omega-3s-stress-and-cancer.html), or a reduction in side effects (http://www.anticancer.org.uk/2012/08/peripheral-neuropathy-and-chemotherapy.html), then it really does begin to seem as though high dose omega 3s should be the one supplement that every cancer patient takes.
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Thanks for a very interesting post Pan, this seems to be a promising discovery.
ReplyDeleteThis research illustrates the difficulty of knowing what the right thing to do is where cancer treatment and diet are concerned. I've been cautious about fish oil since the results of a Dutch study in 2011 which showed that some types of fish oil could actually inhibit the function of some chemo agents. (See http://www.ncbi.nlm.nih.gov/pubmed/21907927 and http://www.telegraph.co.uk/health/8757923/Fish-oil-inhibits-chemotherapy-claim-researchers.html).
I suspect that eventually oncologists will give their patients much more detailed advice about diet and cancer, but this does not seem to be at all common today leaving patients to try and work things out themselves.
Paul.
Paul, I agree it's a bit of a nightmare trying to work out what's safe and what isn't. I'll follow up the references you mention in more detail, but an initial look at the paper suggests that the results they have found are specific to one class of chemotherapy (cisplatin or other platinum-based drugs), and involves specific types of cells. It's worth noting that this same class of drugs is mentioned in the paper that I write about, where a platinum-based drug was used in a phase II clinical trial.
DeleteIt's also worth noting that in the research you mention, they induced drug resistance could be reversed by adding in a COX-1 inhibitor. A perfect example of such a drug would be aspirin, which also has positive benefits - so a combination of omega 3 fish oils and daily aspirin would be worth taking.
Hi,
ReplyDeleteI am currently on a chemo course of cisplatin and gemcitabine, and have been recommended to take EPA and DHA, but only 48 hours after chemo treatment. I am now concerned that this may interfere with chemo, can you please confirm that it will not. Thanks.
Hi Sarah. Obviously I can't confirm that - it's something you should raise with your oncologist if you're concerned about it. What I can tell you is that that combination of chemo drugs with EPA and DHA has been tested in a clinical trial (as well as the individual drugs tested in the test tube and in animals). You can read the report of the clinical trial - in lung cancer patients - here:
Deletehttp://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8640349
I think those results are positive. Another small study looked at a slightly different combination of drugs (carboplatin and gemcitabine, which is pretty much the same as cis + gem), and came to this conclusion:
...supplementation with FO results in increased chemotherapy efficacy without affecting the toxicity profile and may contribute to increased survival.
That study is published here: http://onlinelibrary.wiley.com/doi/10.1002/cncr.25933/full
I hope that proves helpful.
Pan