Trick or Treatment (29 page)

Despite all these examples, which demonstrate that numerous herbs have become part of mainstream medicine, it is important to stress that much of herbal medicine is still considered alternative. In fact, it is easy to make a division between alternative herbal medicine and what might be called scientific herbal medicine. The difference between the two categories becomes clear if we revisit the objectives of the scientists who examined plant-based remedies in the nineteenth and twentieth centuries.

The scientists wanted to identify the active ingredient of each plant and isolate it. Then they sought to synthesize it industrially, in order to mass produce it at a low cost. They even endeavoured to improve on nature by manipulating the molecules of the original ingredient. Crucially, the scientists attempted to evaluate the impact of their treatments on patients to find out which herbal extracts were safe and effective, and which were dangerous or ineffective. The treatments that emerged from this scientific approach to herbal medicine are so utterly mainstream that they are no longer labelled herbal medicines, but rather they are simply incorporated within the realm of modern pharmacology. It is certainly appropriate that the word
drug
comes from the Swedish word
druug
, meaning ‘dried plant’.

On the other hand, alternative herbal medicine generally places an emphasis on using the whole plant or a whole part of the plant, because its underlying philosophy is that these plants have been designed to cure us. Traditional herbalists believe that Mother Nature has engineered the complex mix of substances within a plant so they work in harmony, which means that the plant produces an effect that is greater than the sum of its parts. Herbalists call this
synergy
.

In short, alternative herbal therapists continue to believe that Mother Nature knows best and that the whole plant provides the ideal medicine, whereas scientists believe that nature is just a starting point and that the most potent medicines are derived from identifying (and sometimes manipulating) key components of a plant.

We know that scientific plant-based pharmaceuticals are effective, but the key issue in the context of this book is whether or not alternative complete-plant herbal medicines actually work. Most have not been submitted to the same level of scrutiny as conventional drugs, but there are numerous studies that do shed light on particular herbal medicines. In the next section we have done our best to collate the evidence in order to decide whether each herb is genuinely effective –e.g. does echinacea cure a cold, and can evening primrose oil alleviate eczema?

We will also address an even more important issue, namely safety. As well as knowing which herbal medicines work, patients also need to know which are dangerous and perhaps even lethal.

The herbal pharmacy

Over the last two decades, there has been a plethora of newspaper articles championing the benefits of herbal remedies derived from St John’s wort, a plant that can supposedly act as an antidepressant. Indeed, sales of St John’s wort rocketed in the 1990s, so much so that its consumption increased more quickly than any other popular herbal medicine. But is this sales boom justified? Can St John’s wort really help patients with depression?

St John’s wort (
Hypericum perforatum
), which originates from Europe, would have been recognized by the earliest farmers as a poisonous plant, as it could harm grazing livestock, leading to problems such as spontaneous abortion and even death. Perhaps its toxicity led to the practice of hanging St John’s wort in houses to ward off evil spirits. In time, the tradition evolved so that people would hang the plant on St John’s day, 24 June, soon after its yellow flowers have emerged. The association with the saint’s day is how the plant came to be called St John’s wort, with the appendage
wort
merely being the Old English term for plant.

The notion that St John’s wort could poison evil spirits in the outside world probably encouraged ancient healers to believe that the plant could also poison the evil spirits within us, which they believed were responsible for disease. We know that healers were using St John’s wort to treat sciatica, arthritis, menstrual cramping, diarrhoea and many other conditions over 2,000 years ago, but it was not until the sixteenth century that the physician Paracelsus provided the first documented evidence indicating that the plant was being used to treat mental conditions, otherwise known as
phantasmata
. In the following century, an Italian doctor called Angelo Sala also described how this plant could be used to treat depression, anxiety and madness, and moreover he pointed out, ‘St John’s wort cures these disorders as quick as lightning.’

St John’s wort

St John’s wort continued to be used to treat depression right up to the start of the twentieth century, but it and other herbal remedies gradually fell out of favour as European and American doctors preferred to rely on new drugs that were being developed. Medicine was entering the scientific age, so there was an inevitable tendency to reject ancient natural remedies in favour of new pharmaceuticals. Nevertheless, the tradition of herbal medicine survived in pockets around Europe and America, and there was always a steady stream of anecdotal evidence suggesting that St John’s wort was effective for the treatment of depression. But did these stories of recovery indicate that St John’s wort was genuinely effective, or could they be explained as the result of a powerful placebo effect?

The best way to determine the efficacy of St John’s wort was to submit it to scientific testing, and from 1979 onwards there was a whole series of trials. Most of them originated in Germany, where herbal medicine had retained a core of sympathetic support among some doctors and patients. As often seems to be the case in alternative medicine, each individual trial was unable to give a definitive conclusion about the herb’s efficacy, but over and over again there were tantalizing indications that St John’s wort was more than a mere placebo. The next step was to perform a meta-analysis, whereby all the data from all the trials would be carefully brought together in order to get a firmer grasp of the true value of the plant.

The first meta-analysis of St John’s wort was conducted in 1996 and included the results from twenty-three studies. Referring to St John’s wort by its Latin name of
hypericum
, it concluded: ‘There is evidence that extracts of hypericum are more effective than placebo for the treatment of mild to moderately severe depressive disorders.’ In 1997, the American current affairs TV programme
20/20
said that St John’s wort was ‘a truly remarkable startling medical breakthrough – one that could affect millions of people who suffer from mild depression.’ Thanks to this sort of publicity, sales of St John’s wort in America increased by a factor of 30 in just three years.

The conclusion of the 1996 meta-analysis was reinforced in 2005 by the Cochrane Collaboration. It conducted a systematic review entitled
St John’s wort for depression
, which covered all the thirty-seven trials that had emerged by then. In the context of treating mild or moderate depression, Cochrane stated, ‘hypericum and standard antidepressants have similar beneficial effects’. However, the authors of the review did highlight the limitations of St John’s wort: ‘for major depression, several recent placebo-controlled trials suggest that the tested hypericum extracts have minimal beneficial effects’.

Nevertheless, the overall conclusion for St John’s wort is still positive, as it offers similar benefits to modern drugs in treating mild to moderate depression. It is therefore another tool that can be used to help patients who may not respond to existing conventional drugs. There have been attempts to isolate the key active ingredient in St John’s wort, thought to be either
hyperforin
or
hypericin
, but when these have been tested, however, it appears that they are not as effective as the plant itself. In this particular instance, the herbalist’s view appears correct. In other words, it seems that the benefits of St John’s wort are due to a combination of chemicals, each one working to enhance the effect of the others.

Because it is backed by research, St John’s wort has grown to be one of the biggest sellers in an annual worldwide market for herbal remedies that is now worth roughly £10 billion per year. Today’s pharmacies and health shops offer hundreds of herbal medicines, each one usually promoted as a treatment for several conditions. With so many remedies and conditions, it would be impractical within the limitations of this book to examine each herb in the same level of detail that we have provided for St John’s wort, but we are able to offer a brief verdict on all the bestselling herbal remedies.

Table 1 lists each herbal medicine along with the main conditions that it is used to treat. In each case, the herb is given one of three ratings depending on the research evidence that has been accumulated so far in support of its effectiveness. The ratings are good, medium and poor.

For example, we have given devil’s claw a ‘good’ evidence rating for treating musculoskeletal pain because several high-quality trials have indicated that it is effective and the evidence is uniform – i.e. there are no significant studies that suggest the opposite.

Feverfew is given a ‘medium’ evidence rating for preventing migraine because there have been mixed results from trials – mainly positive, but partly negative. And the positive trials have not been wholly convincing due to the quality of the trials, the number of patients involved and the small effect observed.

Lavender is given only a ‘poor’ evidence rating in the treatment of insomnia and anxiety, because it has undergone very few trials and the results have been contradictory. Interestingly, some very high-profile herbal medicines, such as chamomile and evening primrose, are also classified as being supported only by poor evidence. The reputations of these herbal remedies are probably a result of clever marketing coupled with the placebo effect experienced by the purchasers. In short, it is likely that you would be better off spending your money on effective conventional medicines rather than on herbal medicines with a poor evidence rating.

Table 1 provides a good starting point for appreciating the efficacy of herbal medicines, but four important points need to be made in order to put it into context. First, even though some of the herbal medicines in the table seem likely to be effective for some conditions, there are conventional pharmaceuticals that offer equal or greater benefit in almost all cases. The only important exception is in the treatment of the common cold, because conventional medicines are largely ineffective and echinacea extracts have shown some positive results in trials. Although echinacea may not prevent the onset of a cold, it may be worth taking it during a cold because it possibly reduces the length of the illness.