Whenever I lecture on the topic of alternative medicine for cancer, the first comment from the audience usually is “aren’t there any herbal treatments that are effective?” This is of course a most reasonable question; after all, many conventional cancer drugs originate from the plant kingdom – think of Taxol, for instance.

My answer often upsets believers in alternative cancer remedies. I tell them that, no, there is none and, even worse, there never will be one.

Did I just contradict myself? Did I not just state that many cancer drugs come from plants? Yes, but once the pure ingredient is isolated and synthetized, the drug ceases to be an herbal remedy which is defined as an extract of all the plant’s ingredients, not just one isolated constituent.

And why am I so depressingly pessimistic about there ever being an herbal cancer cure? Because of a simple fact: as soon as a natural substance shows the slightest promise, scientists will analyse and test it. If this process turns out to be successful, we will have a new cancer drug – but not an effective herbal remedy. Again, think of Taxol.

Since almost a decade, colleagues and I have been working on a relatively little-known project called CAM cancer. It started as an EU-funded activity and is now coordinated by Norwegian researchers. Our main aim is to provide unbiased and reliable information about all sorts of alternative treatments for cancer.

Our team is large, hard-working, highly motivated and independent – we do not accept sponsorship from anyone who might want to influence the results of what we are publishing. It is probably fair to say that most individuals who give their time working for CAM cancer are more optimistic than I regarding the value of alternative treatments. Therefore, our publications are certainly not biased against them; if anything, they are a bit on the generous side.

Much of our work consists in generating rigorously researched and fully referenced summaries of the evidence. Before these get published, they are thoroughly peer-reviewed and, whenever necessary, they also get updated to include the newest data. A good proportion of the reviews relates to herbal treatments.

Here are the crucial bits from our conclusions about those herbal cancer remedies which we have so far investigated:

Aloe vera: …studies are too preliminary to tell whether it is effective.

Artemisia annua: …there is no evidence from clinical trials…

Black cohosh: …In all but one trial black cohosh extracts were not superior to placebo.

Boswellia: …No certain conclusions can be drawn…

Cannabis: …The use of cannabinoids for anorexia-cachexia-syndrome in advanced cancer is not supported by the evidence…

Carctol: … is not supported by evidence…

Chinese herbal medicine for pancreatic cancer: …the potential benefit… is not strong enough to support their use…

Curcumin: There is currently insufficient documentation to support the effectiveness and efficacy of curcumin for cancer…

Echinacea: …there is currently insufficient evidence to support or refute the claims… in relation to cancer management.

Essiac: There is no evidence from clinical trials to indicate that it is effective…

Garlic: Only a few clinical trials exist and their results are inconclusive.

Green tea: …the findings… are still inconclusive.

Milk vetch: Poor design and low quality… prohibit any definite conclusions.

Mistletoe: …the evidence to support these claims is weak.

Noni: …evidence on the proposed benefits in cancer patients is lacking…

PC-Spes: …the… contamination issues render these results meaningless. An improved PC-Spes2 preparation was evaluated in an uncontrolled study which did not confirm the encouraging results…

St John’s wort: …there are no clinical studies to show that St. John’s wort would change the natural history of any type of cancer…

Ukrain: …several limitations in the studies prevent any conclusion.

As you can see, so far, we have not identified a single herbal cancer treatment that demonstrably alters the natural history of cancer in a positive direction. To me, this suggests that my rather bold statements above might be correct.

Of course, there will be some enthusiasts who point out that the list is not complete; and they, of course, are correct: there are probably hundreds of herbal remedies that we have not yet dealt with. And, of course, for some of those the evidence might be more convincing – but somehow I doubt it; after all, we did try to tackle the most promising herbal remedies first.

My claim therefore stands: there never will be a herbal (or other alternative) cancer cure. But, please, feel free to convince me otherwise.

25 Responses to Herbal remedies for cancer?

  • This goes to the heart of the problem with SCAM. For SCAM proponents, any evidence, however weak, is an indication they are right, and any study showing no benefit is dismissed because it does not (cannot) conclusively prove that it doesn’t work.

    True believers will never accept anything other than a scientifically rigorous proof of the negative – which in most cases cannot exist – and yet they apply a completely different and vastly lower standard of proof to things they like.

    I do not believe we will ever win this debate on the evidence. I think the only way of winning it is to tackle at source those who spread anti-science bullshit. Global warming deniers, anti-vaxers, Steiner-Waldorf loons, homeopaths, creationists – all are part of a huge anti-science lobby that is now seriously damaging public health through unjustified privileged access to policymakers. They spread the lie that bullshit is equivalent to science. It is a lie, but people who don’t like what science implies would like to believe it.

  • Cognitive dissonance is one of the greatest foes of science and medicine. If people believe that some herbal remedy works because a friend told them it will no amount of scientific evidence will persuade them otherwise. Look how popular faith healing is. Look how popular herbal remedies are in the local pharmacist who has supposedly been trained in science. No doubt the pharmacists are often asked which herbal remedy they should take and the pharmacist obliges. Profit is more important than principles.

  • Thanks for your work in this area.

    One aspect that always concerned me was the advocacy of the same small set of unproven remedies for terminal cancer cases. Always promoted with the same argument – that having tried the “conventional” then they have “nothing to lose”. This would be a reasonable argument to try proven but risky treatments, or under tested treatments, or drugs under trial, but the treatment usually being pushed is homeopathy. Turns out the terminally ill still have something they can lose – money.

  • I am very pro science and against quackery, but I’m having a little trouble understanding what you mean when you say “… as soon as a natural substance shows the slightest promise, scientists will analyse and test it. If this process turns out to be successful, we will have a new cancer drug – but not an effective herbal remedy. ”

    Why couldn’t a natural plant be a cancer cure? if the plant shows promise (i assume that means a demonstrable effect on cancer) doesn’t that mean that it is a natural remedy? how does extracting the chemical somehow diminish what the plant does naturally?

    again, I’m just confused by your statement. I really despise the woo-woo and am not anti science at all.

  • sorry, i did not express myself clearly: if there is good reason to suspect anti-cancwe activity, the extract would be analysed and tested, the molecule that has activity isolated and tested. eventually this process would produce a drug based on a single molecule which, by definition, is not a herbal medicine any longer.

    • I would also argue that the levels of any beneficial component are too low in the natural state to have an effect. On could argue that there is almost certainly a “cure” for just about anything in nature, but nobody would ever b able to consume enough of most of them to ever reach a minimum dose. Just consider how much willowbark tea had to be consumed to cure a headache before salicylic acid was extracted, purified and finally artificially produced to create your common aspirin.

      And just as with willowbark tea, sufficient consumption of the desired active component in the natural state may well result in consumption of undesirable quantities of other components.

  • When I read your list, I find something quite interesting and troubling: It sounds at least to me (unless I get anything wrong) that there are quite a lot of natural remedies where the answer is basically “we don’t know”. At least I interpret “not supported by evidence” and “poor design and quality” as that.

    What I’d like to have is conclusions like “we tested it and to our best knowledge it’s not better than placebo”. In such a case, one can safely say “forget about it”. Your list is a strong indication to me that a lot of those stuff should be tested, because either there is no evidence or the evidence that’s there is not good enough to draw proper conclusions.

    Don’t get me wrong: I’m very critical to alternative medicine and I’m very certain that most likely most of this stuff is bogus and tests would show so. But if one in 20 herbal cancer treatments shows any effect, we should know about it. And if a cancer patient asks “is herbal treatment X an option?” then science should have a better answer than “we don’t know”.

    I’m aware that tests on cancer patients raise severe ethical issues and simple placebo-controlled-trials are usually not an option. Probably such tests should be done alongside the best treatment available – comparing “best treatment available + placebo” with “best treatment available + herbal remedy X”.

  • The trouble here is that science is a poor tool for proving a negative. I do understand the need for clear verdicts. Yet, “not supported by good evidence” and other phraseology is the correct and safe way of expressing a regative result.
    Your second point, trial design: yes, this can be tricky, but there are several potential solutions to potential ethical and other problems

  • Hanno said:

    And if a cancer patient asks “is herbal treatment X an option?” then science should have a better answer than “we don’t know”.

    The fundamental question here is who should be doing the science: there is a clear imperative for those selling these herbal products to substantiate the claims they make; and if they cannot substantiate the claims, perhaps they should not be making them.

  • you said theres no proot on alternative have you proot on conventional to cure cancer take a question on your dr. onco that ill take conventional treat you assure to me to cure my cancer………eye to eye ……

  • Nobody can give such guarantees for singlr cases. Clinical evidence sadly never can provide us with this degree of certainty; it merely is about probabilities, I’m afraid.

  • ask your dr oncologist if i take conventional chemo,radiation,ill be cure,if the dr.said yes ill take conventional.but if he say maybe ill take alternative.

  • Boycea- ask your alternative health care practitioner, eye to eye,that same question. If they say yes, run. No-one should be giving guarantees like that, unless they have serious evidence they’re hiding for no good reason.

    Either they’re lying about it being a definite cure, or they’re cheating other cancer patients and essentially the whole world by not proving it conclusively, when everyone else would know about it and use it.

    Either way they’re completely untrustworthy. This is obvious and intuitive. If they were honest it would either be ‘this has x change of improving your survival but there are no guarantees’, or every hospital in the world would be using it.

  • Please share any results you have regarding the use of Red Clover blossom herbal infusion. Also, flaxseed – I read about a double-blind study involving flaxseed muffins, and lentils.

    The herbs you are testing are dried in pill form? Or are these herbal infusions or tinctures?

    You get pretty much nothing from a dried herb in pill form, so I don’t imagine you would find any positive results.

    In addition, it was my understanding the definition of a drug is a substance toxic at high enough doses? Rather than, as you say, a plant “extract”.

    Many thanks & Green Blessings,


    • Kimberly

      I’m sure Prof Ernst has better things to do that look at every study and every ‘natural’ substance anyone throws at him, but it would be helpful of you could cite this ‘double-blind’ study involving ‘flaxseed muffins, and lentils’ you referred to.

      But what do you think the evidence shows for these products?

      And you do have an odd definition of a ‘drug’.

    • Kimberly,

      Out of curiosity, I performed a web search using the terms: double-blind study flaxseed muffins lentils. The search results included such things as: The recruitment phase of a clinical study is looking for a total of 20 participants; 10 individuals with acute condition [X] and 10 healthy volunteers to test potency of the various types of pulses. WTF? The results would be totally meaningless using only 20 people to test the potency of one variety of pulse let alone various types. I think this shows that the term “double-blind” often just means that both the researchers and the sponsors were blind to the scientific method.

      I am interested to learn why you think there is a dramatic difference between herbs in dried form and herbal infusions or tinctures. Are you saying that dried food has almost no biological effect even though its chemical constituents remain about the same? What about toast, crackers, dry-roasted nuts, cheese, boiled eggs, cooked meats and vegetables (all of which have undergone irreversible chemical changes): are these also ineffective foods?

      The “British Dictionary” on my computer defines the word drug, in this context, as: (noun) a medicine or other substance which has a physiological effect when ingested or otherwise introduced into the body. Obviously, plain common sense is sufficient to figure out that anything (drug or otherwise) that has a physiological effect would be fatal at high enough doses. Drinking far too much water can be fatal even though water is neither a drug nor a toxic substance.

  • Healthcare practices categorized as alternative may differ in their historical origin, theoretical basis, diagnostic technique, therapeutic practice and in their relationship to the medical mainstream.

    • perhaps, but this does not mean that these treatments cannot be tested or that their claims can be accepted untested.

    • It has been fully demonstrated via testing that the Earth does indeed revolve around the Sun, despite the eons of alternative dogma, theories, and diagnostic techniques.

      Our universe doesn’t change its laws to fit popular opinion — neither does science.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Subscribe via email

Enter your email address to receive notifications of new blog posts by email.

Recent Comments

Note that comments can be edited for up to five minutes after they are first submitted but you must tick the box: “Save my name, email, and website in this browser for the next time I comment.”

The most recent comments from all posts can be seen here.