Herbal research problems

How does research apply to herbal medicine, and how is research interpreted and applied?

There are many myths that need to be addressed about the percieved poor quality of research into herbal medicine: The quality of research is good, there is simply not as much herbal related research available as many (particularly herbalists) would like. Undoubtedly, there would be far more research if big profits could be made.

However, the research available is growing everyday, and the quality is constantly improving. A recent review of research concluded that research in herbal medicine may be better quality than many drug trials:

‘Our findings challenge the widely held belief that the quality of the evidence on the effectiveness of herbal medicine is generally inferior to the evidence available for conventional medicine.’
(Nartey et al 2007)

Double Blind Placebo Controlled Trials

All herbalists would welcome more good quality research, to further refine our traditional knowledge of herbs. However, there are many problems.

The model considered the ‘gold standard’ in medical research – the double blind placebo controlled trial (DBPCT) is completely inappropriate for assessing herb action. Some key problems with the DBPCT are:

  1. Herbalists do not treat disease, we treat people. 100 people with disease X may require 100 different treatments. DBPCTs attempt to average the group by treating with the same medicine.
  2. A consultation with a herbalist is a complex multi-variable affair. There is the direct therapeutic effect of the herbs, the councelling time, the interpersonal dynamic, the medical models that give hope and vision, and the awareness of our ability to self-heal. All can have a positive effect on therapeutic outcome. This is critical, since I would not expect some herbs to ‘work’ without the surrounding support structure. That some seem to (e.g. Hypericum in depression), actually surprises me. Herbs are not drugs!
  3. Placebo’s are potentially impossible in herbal medicine where (1) The taste/smell of the medicine is part of the therapeutic effect and (2) The conscious, positive engagement of the patient is a key part of the therapeutic intention – this is participatory medicine.
  4. My experience is that the majority of healing is a process, not a single step, single medicine cure. The ‘magic bullet’ approach can be appropriate in some instances, e.g. acute infective disease, but is not at all appropriate for deep seated health issues that can gradually improve through a process of positive and gentle intervention.
  5. ‘Intention to treat’ – That a patient chooses to engage with a treatment is important to the therapeutic outcome. For instance – I find that when someone’s wife/parent etc has ‘persuaded’ them to come for treatment, making a positive impact is more difficult than when someone, of their own free will, chooses it. In a placebo controlled trial this factor is removed, since the patient is engaging with a ‘trial’, not with a person who will be part of their healing process.
  6. Based on DBPCT methods and their grandfather ‘evidence based medicine’, their is no evidence that parachutes will save your life when jumping out of a plane. ( Article in the BMJ ) Evidence based medicine and DBPCT’s risk missing out on a lot.

Other points include:

  • Contrary to some anti-alternative extremists (of the ‘it’s all mumbo jumbo’ sort), there are thousands of good research papers relating to herbs. If you are interested, a ‘PubMed‘ search under any herb name (e.g. Curcuma) will find much interesting research. The chart below gives a sense of the emerging research around herbal medicine (from Wikipedia article on ‘herbalism’) :
    This graph was obtained by searching for ‘phytotherapy’ in Pubmed. A search on 18th December 2009 gave 20,650 results.
    There is, however, relatively little research in herbs compared to drugs.
  • Poor trial design. I have seen a number of trials which, if evaluated by a herbalist, would not stand come even close to best practise in herbal therapeutics. Herbalists work with herbs in a holistic manner, and the herbs work for us well in the model of therapeutics. Doing a trial to test if herb X is good for condition Y is riddled with flaws, not least because a herbalist would treat 100 patients with condition Y with 100 different preparations, geared towards them individually.
  • Lack of evidence of efficacy is NOT proof of inefficacy. Let’s say a poorly designed trial comes out with a neutral or negative result – this is often then siezed upon as evidence that the herb is useless. This is logically, rationally and scientifically flawed. Such results simply indicate lack of evidence of efficacy based on the outcome measures of that particular trial.

A tongue in cheek and overly exaggerated example:

  • Trial:
    There is research evaluating St.John’s Wort’s antidepressant function by making rat’s swim until they drown, and watch if the herb helps them swim longer (no joke – this is a real research method)
  • Result:
    There seems to be a slight increase in swimming time but insufficient to be statistically significant.
    This research does not demonstrate the efficacy of St. John’s Wort to help rats swim longer before drowning.

Once its been through chinese whispers: SJW is useless for depression.

This is obviously ridiculous when put like that – but this mistake is repeated daily in the press and even in some ‘scientific’ publications.

In practice……

When there’s not enough research to form a conclusion what do you do? On a personal level, I always check traditional data on usage, look at my own experience of the herb, see if there’s a conceivable model for how the herb may work, and check the safety data. I will work with that herb with a patient only if I am confident of the efficacy and safety of the herb. If there is an acceptable, ‘evidence-based’ alternative then I’d always recommond people go for this – the trouble is, many such interventions are not acceptable to the patient, possibly due to side effects or a dislike of symptomatic treatment.

When there are ill people who can be helped, I’d consider it unethical to wait for decades of further research when we have such a rich traditional evidence base albeit not in the style of orthodox medical research models. Of course safety is paramount, yet herbs used appropriately are very safe – and this is what herbalists are trained to do (Inappropriate use can be v.dangerous)

I would propose that ‘evidence-based-absolutism’ is potentially unethical in:

  1. Turning people away from potentially helpful (though not fully researched) treatments
  2. Creating the nocebo effect of a ‘nothing else can be done’ narrative given be a trusted authority.