November 5, 2012

Does it work? Does it matter?

The new proposed law for ‘natural remedies’ will provide some limits on health claims: they must be supported by scientific evidence or traditional evidence.  It’s depressing that this has to be considered an improvement over the current situation.  It’s also unfortunate that there is a special exemption for the largest category of health claims that have support neither from tradition nor science: homeopathic remedies (invented in 1796).

If ‘traditional’ evidence required a tradition of use of the product in essentially the form being sold and for essentially the indication being marketed, I wouldn’t object.  So, for example, it’s reasonable to say that ginger has been used traditionally in China to stop coughing, because it has. Many people would consider this sufficient reason to buy and use ginger for coughs, and I don’t see why there’s a vital national interest in deterring them.  What should be stopped is the ability to claim that a treatment is known to work simply because it has been traditionally used, and the ability to make up new ‘traditional’ uses for marketing convenience.

In the end, the impact of the law will depend on regulations and enforcement, not on statute.

Requiring ‘scientific evidence’ won’t get us very far without standards for the level of evidence required.  As StatsChat readers know, a huge variety of plant extracts have been shown to kill cancer cells in test tubes, or affect biochemical measurements in cell cultures. Newspapers are willing to take this as sufficient basis for stories and headlines claiming ‘can prevent cancer’ or ‘is helpful in treating diabetes’. If the proposed Authority takes a similar view, almost anything will be allowed.

Enforcement is also critical.  In theory, the US requires vendors to have scientific evidence for claimed health effects of natural remedies, but in practice they can get away with almost anything, because the FDA doesn’t have the resources for enforcement and there’s no practical way for private citizens to act. At the moment, the NZ Advertising Standards Authority has the ability to remove ads making health claims for which the vendor cannot supply evidence, and they have the willingness to act on public complaints from anyone who is unhappy about misleading health claims. The new law’s requirement for prior notification of health claims could strengthen enforcement, or weaken it, depending on how the requirement for evidence is interpreted.

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Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »

Comments

  • avatar
    Graham Harris

    Rather than setting a single hurdle, which will be subject to impassioned negotiation and result in exceptions like homeopathy- why not a star marking system like for appliance energy efficiency.
    Stars would indicate the strength of the scientific support with each star representing a pretty black and white threshold.
    Products would probably end up with a star rating that’s more or less correct, and it would allow individuals to exercise choice better.

    11 years ago