●Introduction 97
●Garlic 97
●Ginseng 98
●Ginkgo biloba 99
●Echinacea 99
●Soy 99●Saw palmetto 100
●St John’s wort 100
●Glucosamine 101
●Miscellaneous herbs recently found to be toxic or
meriting their withdrawal from the market 101CHAPTER 17
ALTERNATIVE MEDICINES: HERBALS
AND NUTRACEUTICALS
INTRODUCTION
‘Alternative’ therapies (i.e. alternative to licensed products of
proven quality, safety and efficacy) span a huge range from
frank charlatanry (e.g. products based on unscientific postu-
lates, composed of diluent or of snake oil), through physical
therapies such as massage and aroma therapies which certainly
please (‘placebo’ means ‘I will please’) and do a great deal less
harm than some conventional therapies (e.g. surgery, chemo-
therapy), through to herbal medications with undoubted
pharmacological activity and the potential to cause desired or
adverse effects, albeit less predictably than the licensed prod-
ucts that have been derived from them in the past and will no
doubt be so derived in the future. Medicine takes an empirical,
evidence-based view of therapeutics and, if supported by suffi-
ciently convincing evidence, alternative therapies can enter the
mainstream of licensed products. Overall, efforts to test homeo-
pathic products have been negative (Ernst, 2002) and it has been
argued that no more resource should be wasted on testing prod-
ucts on the lunatic fringe, even when they come with royal
endorsement and (disgracefully) public funding. Here we focus
on herbal and nutraceutical products that may cause pharmaco-
logical effects.
Herbal remedies include dietary supplements (any product
other than tobacco intended for ingestion as a supplement to
the diet, including vitamins, minerals, anti-oxidants – Chapter
35 – and herbal products), phytomedicines (the use of plants or
plants components to achieve a therapeutic effect/outcome)
and botanical medicines (botanical supplements used as
medicine). The recent increase in the use of herbal remedies by
normal healthy humans, as well as patients, is likely to be mul-
tifactorial and related to: (1) patient dissatisfaction with con-
ventional medicine; (2) patient desire to take more control of
their medical treatment; and (3) philosophical/cultural bias. In
the USA, approximately one-third of the population used some
form of complementary or alternative medicine (the majority
consuming herbal products) in the past 12 months. At a clinical
therapeutic level, it is disconcerting that 15–20 million
Americans regularly take herbal remedies, while concomi-
tantly receiving modern prescription drugs, implying a signif-
icant risk for herb–drug interactions. In Scotland, some 12% of
general practitioners and 60% of general practices prescribe
homeopathic medicines! Herbal remedies are particularly
used by certain groups of patients, notably HIV and cancer
patients. The stereotypical user is a well-educated, career pro-
fessional, white female. From a therapeutic perspective, many
concerns arise from the easy and widespread availability,
lack of manufacturing or regulatory oversight, potential
adulteration and contamination of these herbal products.
Furthermore, there is often little or no rigorous clinical trial
evidence for efficacy and only anecdotes about toxicity. Many
patients who are highly attuned to potential harms of conven-
tional drugs (such as digoxin, a high quality drug derived his-
torically from extracts of dried foxglove of variable quality
and potency) fail to recognize that current herbals have as
great or greater potential toxicities, often putting their faith in
the ‘naturalness’ of the herbal product as an assurance of
safety. This chapter briefly reviews the most commonly used
herbals (on the basis of sales, Table 17.1) from a therapeutic
perspective and addresses some of the recently identified
problems caused by these agents.GARLIC
Garlic has been used as a culinary spice and medicinal herb for
thousands of years. One active compound in garlic is allicin,
and this is produced along with many additional sulphur
compounds by the action of the enzyme allinase when fresh
garlic is crushed or chewed. Initial clinical trials suggested the
potential of garlic to lower serum cholesterol and triglyceride,
but a recent trial has shown limited to no benefit. Garlic has
been advocated to treat many conditions, ranging from many
cardiovascular diseases, e.g. atherosclerosis including periph-
eral vascular disease, hypertension, lipid disorders and sickle