9

There is a sensational article in slate that says there's an herbal tea containing Artemisia that will prevent malaria that is being discouraged by the establishment because it could cause resistance to future drugs. Does this tea actually work?

16

I agree with Larry at the crucial parts of the article. To explain a bit:

The WHO is nowhere near hiding Artemisia for anti-malaria medication. In fact, four drugs prepared from the plant are on their list of essential medicines.
But: these are to be used in drug combinations. What the WHO is very much concerned about is drug resistance, which is also mentioned in the article:

[M]alaria experts worry that unregulated use of this tea could cause the malaria parasite to develop resistance to artemisinin drugs.

Now about the arguments the article has in favor of the home-grown tea:

[A] randomized controlled trial on this farm showed that workers who drank it regularly reduced their risk of suffering from multiple episodes of malaria by one-third.

Meaning that 2/3 of people run around with a dosage of the artemisinin that is too low to prevent malaria. And not only 2/3 of the patients, but 2/3 of the population and all the time. This is a very promising condition for breeding resistance.

The fact that

in Wagagai, after years of preventive use, resistance has not sprung up.

just means that they have been lucky so far.

Neither can the fact that

artemisinin resistance is [found] on the Thai-Cambodian border, where conventional artemisinin drugs are used

be an excuse for advertising a practice that increases the risk of resistance.

BTW, finding resistance where the conventional drugs are used is not entirely unexpected. For one thing, also with the proper medication, underdosage is not uncommon, and there are low quality/dosage counterfeit drugs. This post gives a similar discussion for the region in Cambodia where the resistance came up.

In their statement "Effectiveness of Non-Pharmaceutical Forms of Artemisia annua L. against malaria" the WHO explains that

  • Total recovery of artemisinin from plant leaves was found to vary by a factor of 150
    This prevents any practicable recommendation for dosing the tea.
  • the leaves need to be stored cool and dry to prevent loss in artemisinin
  • In the end, the prepared tea has too low artemisinin concentration:

    In order to receive a dose equivalent to a 500 mg artemisinin tablet or capsule, patients would be required to drink as much as 5 litres of A. annua tea per day [...] In practice malaria patients are drinking only 1 litre

    So the result of the tea is currently a severe underdosage.

  • They also cite studies who found eating plant material more effective than drinking the tea, but nevertheless a high recurrence rate was observed, to that is still not an effective treatment.

Here's a newspaper article in German about a desastrous failure of establishing Artemisia farms in east africa. Among other interesting details, there is a sentence

Growing Artemisa plants is not as easy as the aid and development agencies thought.

That is, the plants did grow, but the small farmers didn't get the drug content that was achieved in the test beds, and the extraction of the artemisinin yielded only half of the content (plus possibly other quality issues).

So I understand the WHO is not against the use of Artemisia, but it is strictly opposed to advertising a "use" of the plant in ways that are ineffective and create a severe risk of worsening the situation.

10

Although thought-provoking, the article doesn't claim either that the tea "will prevent malaria" or that the WHO is "trying to hide" it.

Rather it says:

[A] randomized controlled trial on this farm showed that workers who drank it regularly reduced their risk of suffering from multiple episodes of malaria by one-third.

and

[M]alaria experts worry that unregulated use of this tea could cause the malaria parasite to develop resistance to artemisinin drugs.

The closest thing to "hiding" the drug is this troubling paragraph:

When Ogwang tried to publish the results in Malaria Journal, a reviewer largely praised the quality of the science but nixed publication out of concern that use of the tea could render ACTs ineffective. It’s a remarkably patronizing recommendation: that a scientific journal should keep the latest evidence out of the hands of Africans, lest they begin treating themselves. Marcel Hommel, editor in chief of the journal, defends the decision, saying, “It is the responsibility of an editor to avoid publishing papers that promote interventions which could potentially put patients at risk.” Ogwang eventually published his results in a less prestigious journal.

  • 2
    To be fair, Larry, that is a troubling paragraph, and comes dangerously close to hiding the results. – Konrad Rudolph Apr 7 '13 at 10:58
  • 1
    Konrad, I agree that the article is well worth the read and makes its points well. In my opinion, the issues don't need to be overstated as "hiding a cure" in order to be worthy of attention and debate. – Larry OBrien Apr 7 '13 at 19:54

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