Herbal medicine – how does it work?
When I tell people I’m a herbalist, they invariably respond in one of three ways.
The first, most common response is – “Oh, my sister takes homeopathy – she swears by it!”
My reaction to this is always the same – “That’s nice, but in fact herbal medicine is quite the opposite of homeopathy. We use whole plant extracts, whereas they use infinitesimal dilutions and the final preparation contains very few pharmacologically active compounds.”
Blank stares ensue, then someone changes the topic.
The second response is – “So you believe in that, then?’ This is my favourite one. I simply reply “do you believe in carrots?” with a big smile on my face.
The third, more engaging response is – “Herbal medicine… how does that work then?”
“Good question,” I say.
Herbs vs pharmaceuticals
When talking about how herbs work, the most obvious point of reference is to compare them to pharmaceutical drugs.
Conventional medicines are single, active ingredients. These are often derived from plants – such as morphine from the opium poppy or aspirin from willow bark.
Take aspirin for example. It inhibits the cyclooxygenase (COX) enzyme and the formation of inflammatory compounds, and has blood thinning, pain relieving, anti-inflammatory and fever reducing effects.
It is quick and effective, producing the same result in everyone who takes it.
Over time, or if consumed too much, it causes problems – for example, it can cause stomach ulcers by interfering with natural inflammatory responses in the stomach.
Single ingredient medications are strong and direct, and have specific side effects. They are highly useful in the short term but, by nature, cause problems in the long term.
The reverse is true with herbal medicine. Herbs are whole plants – they contain a vast array of plant chemicals which modulate and interact with human physiology in a complex way.
Often it will be a few weeks or months before a plant has exerted its full potential on the body, and the same herb will produce different effects in different people depending on their condition, or physical ‘terrain’.
For example, take yarrow (Achillea millefolium). A traditional European anti-inflammatory, circulatory and fever-reducing herb with a special affinity for the female reproductive system, yarrow both stimulates a weak menstrual flow and stops a heavy one.
It does this by responding to the terrain of the patient. A perimenopausal woman with a heavy flow will benefit from its anti-haemorrhagic effects, whereas a teenage girl with light bleeding and painful periods will require its antispasmodic action on the uterus, releasing tension and encouraging flow.
The gentler, multifaceted nature of herbs means side effects are not as common. Only a handful of herbs are extremely powerful or toxic in small doses, and most herbs can be taken for months or years at a time.
Where’s the evidence?
The hugely diverse chemical composition of a herbal prescription, combined with the fact that herbs affect people differently, means that herbal medicine is difficult to pin down in the laboratory.
Scientific research methods do not lend themselves easily to so many variables, and clinical trials are expensive! Who is going to pay for research into a herb that can’t be patented into a sellable drug?
The evidence base for herbal medicine needs a lot of work, I’ll admit – but we do have some ‘gold standard’ clinical trials on some of our favourite herbs already.
Take St John’s Wort (Hypericum perforatum), one of our best ‘nervines’ or herbs for the nervous system. It calms anxiety, defuses panic and lifts the spirits, letting light into the dark corners of the mind.
It has become known in recent years as the ‘depression herb’ – after decades of clinical trials, a 2008 review found St John’s Wort to be more effective than placebo as well as being similarly effective to standard antidepressants, with fewer side effects (1).
What we need is more evidence like this, to back up what we have instinctively known for centuries – that herbs really do work, in their own unique ways.
In the herbalists’ view, the complex nature of herbs is perfectly suited to the complex needs of the human body, especially in situations of chronic ‘disease’.
And considering the epidemic of chronic disease sweeping across the globe, we need our herbs now more than ever.
1. Linde K, Berner MM, Kriston L.
St John’s wort for major depression. Cochrane Database of Systematic Reviews 2008, Issue 4. Art. No.: CD000448. DOI: 10.1002/14651858.CD000448.pub3
By Poppy Burr
Poppy is a UK-trained medical herbalist practising in Praia da Luz. She offers consultations and treatment in Western Herbal Medicine, incorporating Functional Medicine testing and nutritional strategies where appropriate. For more information, visit poppytheherbalist.com.