Alternative medicine: General principles
1. Herbal medicine
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| Aloe vera |
Herbalists use plant-derived medicines at doses where true pharmacological effects can occur and can be measured (this is in contrast to homeopathic medicine). For example, the herbal product guarana comes from a plant Paullinia cupana which naturally contains large amounts of caffeine so it is taken to improve alertness, but it can also produce the side effects of caffeine such as insomnia and anxiety. Conversely, valerian is from the flower Valeriana officinalis
and its constituents have CNS depressant actions so it is taken as a sedative. This means it can generate unwanted sleepiness as a side effect and it has even been reported to cause a withdrawal-type reaction if stopped after long-term use, similar to benzodiazepines.
Herbal products may be administered by various routes. Usually they are taken orally, but Aloe vera, is an example that is commonly applied topically, and mistletoe (Viscum album) is sometimes given by injection.
2. Homeopathic medicine
The two main principles of homeopathic medicine are:
- ‘Like cures like’ – a patient’s symptoms are treated with a substance that could cause the same symptoms.
- The more dilute a preparation, the more potent it is.
Plants yield most of the original ingredients in homeopathic medicines, but the solutions used are very dilute. Two systems of dilution exist for homeopathic remedies – decimal ('x') and centesimal ('c') – but the strengths 6c and 30c are common. It is worth noting that dilutions of more than 12c or 24x are unlikely to contain any molecules of the active ingredients.
There is no evidence that homeopathy is effective as a treatment for any health condition.
3. Dietary supplements
In the UK, dietary supplements are defined as ‘foods’ in unit dosage form (e.g. tablets, capsules, liquids) taken to supplement the diet. Most are products containing nutrients normally present in foods. They may include vitamins and minerals, oils containing fatty acids (e.g. fish oils), plant-based substances (e.g. garlic) or other ‘natural’ substances that claim to have beneficial effects (e.g. royal jelly).
