Number 94 October 1996
MAFF UK - TRADITIONAL REMEDIES AND DIETARY SUPPLEMENTS: SURVEILLANCE
Index to MAFF UK Food Surveillance Information
Sheets, 1996
See also:
115: MAFF UK - Survey of Dietary
Supplements Containing Vitamin B6
Summary
The final results from a project investigating adverse health effects
arising from use of traditional remedies and dietary supplements are now
available. The work was carried out on behalf of the Ministry and Department of
Health by the Medical Toxicology Unit (MTU) of Guy's and St Thomas's Hospital
Trust, London. The aim of the work was to investigate whether the use of
traditional remedies and dietary supplements were associated with adverse health
effects.
A pilot project ran from April 1991 to March 1992. Results of this work
have already been published 1 and suggested
that herbal preparations/traditional remedies rather than vitamins/minerals
should be targeted for more detailed follow-up. A further 4 years' surveillance
was carried out between April 1992 and March 1996. Overall the results of the
project did not indicate the existence of significant health problems for
dietary supplements. However, the survey identified cases where the use of
certain Chinese herbal medicines (CHM) were shown to be possibly associated with
liver damage. Traditional remedies from the Indian Sub-Continent which
contained high levels of heavy metals caused a number of cases of illness.
Unlicensed products containing high levels of heavy metals are not in any case
permitted under food or medicines legislation.
Background
In 1991 the joint MAFF/DH Working Group on Dietary Supplements and Health
Foods published a report 2 which identified:
- the potential for adverse health effects from dietary supplements and "health
foods"; and
- ways in which consumers might be misled by information (e.g. labelling,
advertisements) about dietary supplements and health foods.
It noted that the boundary between foods and medicines was not always clear
and that some herbal ingredients which were deemed unacceptable on safety
grounds for use in medicines could still
legally be sold as foods. It was also clear that there were potential
health hazards from dietary supplements and traditional remedies since at that
time germanium, tryptophan, 'slow release' niacin and vitamin A had all caused
concern. However, insufficient information was available to show whether
serious or widespread problems were occurring. This was partly due to a lack
of a specific scheme for reporting adverse reactions to remedies and dietary
supplements and also to the fact that many health professionals were unaware
that these products might have side effects and that they should therefore
routinely ask patients about usage. To address these concerns and enable MAFF
and DH to identify public health issues, a project was set up at the MTU.
The MTU provides medical practitioners and the emergency services with
information and advice in cases of human poisonings. All enquiries to the MTU
are logged, together with details such as the age of the patient, severity of
symptoms and suspected causative agent(s). The MTU was thus ideally placed to
carry out retrospective and prospective surveys of the cases reported to it and
also to provide feed-back to the health professionals to raise their awareness
of the potential problems associated with dietary supplements and traditional
remedies.
Two specific problem areas were identified concerning the use of traditional
medicines from China and the Indian Sub-Continent and both were considered by
the Department of Health's independent advisory Committee on the Toxicity of
Chemicals in Food, Consumer Products and the Environment (COT) and MAFF's
independent Food Advisory Committee (FAC). The Committees recommended that an
education programme be undertaken involving herbal practitioners, GPs and the
public about the potential problems from some of these remedies.3 They also recommended that suppliers should be
advised of the need to comply with relevant legislation (e.g. the Medicines Act
1968 and the Food Safety Act 1990). However, they were concerned that there was
still confusion about the legislative division between foods and medicines and
suggested this should be re-examined to ensure that remedies are controlled in
the most appropriate way.
The Medicines Control Agency has confirmed that where a herbal remedy is
made up and dispensed by a practitioner, then it is considered to be an
unlicensed medicinal product and as such is exempt from licensing under The
Medicines Act 1968 and The Medicines for Human Use (Marketing Authorisations,
etc.) Regulations 1994. However such products are also covered by the
provisions of the Food Safety Act, which only specifically excludes licensed
medicines.
Methods
One of the main aims of the work was to determine whether causal
relationships could be established between the products used and the symptoms
reported. Thus, as much background information as possible about usage of
medicines, supplements and remedies was collected and wherever possible clinical
and product samples were obtained and analysed as appropriate. In addition,
clinical information from GPs and hospital clinics was collated.
Cases were classified as confirmed, probable, possible, conditional or
unassessable with regards to the link between symptoms and products. These are
defined as follows:
- confirmed: there was confirmed poisoning, rechallenge or the
effects were confirmed to be related to the activities of the ingredients of
the products used;
- probable: there was confirmed poisoning, rechallenge or the effects
were clearly related to the activities of the ingredients of the product used;
- possible: there was only a single exposure or there was a lack of
follow-up information or it was not possible to exclude other causes;
- conditional: here, despite considerable investigations, the final
assessment cannot be made;
- unassessable: information is insufficient or contradictory and
cannot be supplemented or verified.
Results
An overview of the numbers of cases where people reported symptoms is given
in Table 1. This relates to the number of enquiries
where people reported symptoms after ingesting a particular product. The
increased numbers reported during 1992 to 1996 reflect an overall increase in
the number of cases referred to the MTU as a result of their efforts to increase
awareness and encourage health professionals to consider the potential for
adverse effects in people taking dietary supplements or traditional remedies.
The majority of enquiries related either to vitamins/minerals or herbal
products/traditional remedies with the latter category outnumbering the former
by a factor of 2 to 1.
In Table 2, details are given of those enquiries
in table 1 where a type of relationship could be established between the
symptoms reported and the different types of products. In this table, herbal
products and traditional remedies have been subdivided. It can be seen that in
only 12 cases was it possible to confirm a link between the product and the
symptoms experienced, nine of these cases related to traditional remedies from
the Indian Sub-Continent. These were found on analysis to contain substantial
amounts of heavy metals such as lead and mercury. The presence of the metals
was not due to contamination but to deliberate use of the metals. A further
case involved accidental poisoning with a Chinese liniment. When interpreting
these data, consideration also needs to be given to the severity of the symptoms
reported. In the case of vitamins and minerals, the main symptoms observed were
gastro-intestinal effects which were transient and not serious. There was only
one case where a direct relationship could be confirmed between product and
symptoms. This was a male who suffered liver failure due to copper poisoning.
He was found to have had a copper intake of 60 mg/day for 1 year and of 30
mg/day for three years. While this particular case highlights the need not to
take excessive doses of supplements, the overall findings on vitamins and
minerals do not point to their raising serious public health concerns.
The final confirmed case involved ginseng. An elderly patient developed
hypertension after taking Siberian ginseng for 16 years but the effect was
reversible i.e. it stopped when the patient stopped taking the supplement. The
survey has identified cases where the use of certain Chinese herbal medicines
has been associated with liver damage. Details of a number of the cases, one of
which was fatal, have already been published4. Where analysis of the material in the Chinese
herbal medicine was possible, no single ingredient could account for the liver
damage. The reactions were not dose related and appear to be idiosyncratic.
Interpretation
Overall the results of the project do not indicate the existence of
significant public health problems associated with traditional remedies and
dietary supplements in general. The two groups of products for which the most
severe adverse reactions were recorded were Chinese herbal medicines, which were
associated with liver toxicity, and traditional remedies from the Indian
Sub-Continent containing high levels of heavy metals. Herbal remedies when made
up and dispensed by a practitioner, are regarded by law as medicinal products
but are exempt from licensing. Traditional remedies containing ingredients not
of herbal origin are not exempted from licensing. The Medicines Control Agency
takes action to protect public health when problems arise through enforcement
proceedings, restriction of supply and issuing warnings to users. It plans to
extend its present monitoring of adverse reactions arrangements for licensed
medicines to unlicensed medicines to facilitate identification of problems that
require action.
The project has been useful in encouraging health professionals to become
more aware of potential problems which may be associated with adverse reactions
arising from the use of traditional remedies in particular herbal preparations.
The MTU has liaised closely with practitioners of Chinese Herbal Medicine in
particular during the course of the surveillance exercise and has encouraged
them to monitor liver function in the patients they treat. It has established
that in some of the cases reported herbs have been misidentified or the wrong
herb supplied. A reference collection of Chinese medicinal herbs in the UK
would help to remedy such problems and the Royal Botanic Gardens at Kew have
drawn up a proposal for such a collection. They are currently seeking a source
of funding.
References
- Ministry of Agriculture, Fisheries and Food (1994).
Naturally Occurring Toxicants in Food. Food Surveillance Paper No. 42.
HMSO
- Ministry of Agriculture, Fisheries and Food (1991).
Dietary Supplements and Health Foods. Report of the Working Group. MAFF
Publications.
- MAFF/DH Food Safety Information Bulletin No.
55 (Nov. 1994)
- L Perharic et al. (1995). Possible Association of
Liver Damage with the use of Chinese Herbal Medicine for Skin Disease. Veterinary
Human Toxicology 37 (6) p562-566.
Contact points
For further infomation on specific details of the cases and the way in which
the work was carried out, please contact:
Traditional Remedies Surveillance Project
Medical Toxicological
Unit
Guy's and St Thomas's Hospital Trust
Avonley Road
London SE14
5ER
Tel: +44 (0) 171 717 5382
Fax: +44 (0)171 635 1056
For further information about the project in general please contact:
Dr Julie Norman/ Dr David Atkins
MAFF, Food Safety and Science
Group
Food Contaminants Division
Ergon House, c/o Nobel House
17 Smith Square
Tel: +44 (0) 171
238 6198
Fax: +44 (0)171 238 5331
A copy of the report entitled "Toxicological problems resulting from
exposure to traditional medicines and food supplements" can be obtained
from:
The Library
Ministry of Agriculture, Fisheries and Food
Rm
807 Nobel House
17 Smith Square
London SW1P 3JR
Tel: +44 (0) 171
238 6575
Price: £11.20 + £1.50 post and packaging.
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