Memorandum submitted by Professor André
McLean (E1(a))
I have the honour to submit my written evidence
to the House of Commons Agricultural Committee regarding vitamin
B6. I write in my personal capacity and I am not expressing the
views of the department or University College London. Nor am I
acting at the behest or payment of any organisation.
WRITTEN EVIDENCE TO THE HOUSE OF COMMONS
AGRICULTURE COMMITTEE
Evidence regarding the existing and future role
of government, its expert advisory committees and executive agencies,
etc, in determining the degree of health risk to individuals from
intake of vitamin B6.
Evidence from Professor Andreé E M McLean,
Professor of Toxicology, University College London (Emeritus).
Former member of COT.
Former member of Committee on Safety of Medicines
(CSM).
Former member of government committees concerned
with pesticides (PSPS Scientific Sub-Committee), radioactive waste
management (RAWMAC) and Panel on Child Nutrition.
Former Chairman of British Toxicology Society.
Former Chairman of Panel of Examiners in Toxicology
at the Royal College of Pathologists.
1. I write as one who has been concerned
in giving toxicological advice to a wide range of government committees
on a wide range of issues. I am concerned about the decisions
taken on the subject of vitamin B6, and I am writing because I
am concerned that toxicological information should be correctly
used, and not presented in a way which allows arbitrary decisions
to appear to be based on science.
2. There is a very real problem in that
food supplements are sold, frequently without adequate evidence
of efficacy, without proper labelling, without warnings of toxicity,
without proper control. A product may be sold with no claims on
the bottle while, on the next shelf, there is a booklet extolling
the virtues of some substance for which there is no evidence at
all that it is any use. This is a consumer protection issue to
which Consumers' Association has rightly drawn attention,
particularly on the matter of labelling. Responsible manufacturers
and retailers have in the past been willing to withdraw some notorious
examples such as germanium, for which there was no acceptable
evidence that it was of any use at all, when this was pointed
out to them, but that is too clumsy a mechanism for proper control
of these products.
3. In the case of vitamin B6 there are good
arguments for labelling the material to state that doses over
200 mg per day may be dangerous and that the evidence for its
efficacy is minor or insufficient for it to be given a product
licence as a medicine. Any safety and consumer protection issues
could be dealt with in this way once there is a mechanism for
doing so. Similar measures could be taken to control the sale
of food supplements of many kinds, although it must be recognised
that it is only a few years ago that the increased intakes of
folic acid, anti-oxidant vitamins, vitamin B6 and B12, which are
now recommended in standard medical journals, would have been
regarded as quite outrageously high. Our knowledge of medicine
and the human body changes more rapidly than received wisdom.
4. In these circumstances it is worrying
that COT and following on from COT, CSM, have raised issues of
toxicity which seem to me to be entirely spurious with which to
justify action on regulation of sale of vitamin B6. In particular,
COT claimed that the use of a large safety margin (a factor of
300 between animal evidence of toxicity and acceptable human intake)
is "an internationally recognised procedure". This is
false and likely to mislead any non-specialist reading the statement.
What is internationally recognised is that we use large safety
margins when dealing with contaminants of foodstuffs such as pesticide
residues, or additives that are added for technical or sales reasons,
such as colourings and anti-oxidants. These safety margins are
never used for the plain material which the customer wishes to
buy. Nor could such wide margins be used because it would lead
to the immediate banning of substances such as coffee, sugar,
salt, all of which are consumed in quantities which are not far
from those which could be shown to have adverse effects. If such
large safety margins were generally accepted it would mean that
essentially any substance could be made subject of regulation
or ban at the arbitrary will of the government agencies for that
sector of the economy. It ignores the basic principle that "all
substances are toxic, only the dose makes a thing not a poison"
(Paracelsus, 1493-1541).
5. The human evidence which the COT has
put forward in justification of its actions is equally weak, consisting
mainly of a study by Dr Katharina Dalton of which she herself
said "It is a preliminary study; I wish someone would do
it again properly" and which has been widely criticised as
being essentially useless. In my experience, it is unheard of
for so weak a study to be used for regulatory action 10 years
after it was published. COT claim that there is a mass of other
evidence justifying action on B6, but it is not disclosed and
does not appear in a search of the scientific data.
6. Overall, this decision looks as if a
real question of social policy, which might require legislation
to deal with it, has had a gesture thrown at it, invoking spurious
toxicological arguments.
7. If I may comment on the present situation.
All the advisory scientific committees for government on which
I have had the honour to serve have had to deal with conflicts
between different sectional interests, for instance, on the Pesticide
Committee we were terrified of doing anything which harmed bees
because it was well known that bee keepers were liable to swarm
and descend on MAFF at the least provocation. COT was particularly
liable to be influenced by the large food companies who were determined
not to have imposed on them the need to label really dangerous
material such as gluten or peanuts, which regularly cause illness
and deaths in people who unwittingly consume them. It is unfortunate
that many committee members, drawn from science, business, medicine
or industry, seem unwilling to recognise that they are acting
as points of mediation between these different interest groups.
Civil servants may well deny that in the course of dealing with
a particular industry or professional group they gradually take
on the ethos of the major players with whom they deal on a day-to-day
basis. The regulator can become the spokesman for the group that
is to be regulated. Very often they do not recognise that the
industry may be fragmented and that there are conflicts of interest
between large and small companies. For instance, in Pesticide
Committee a large company with a large research and development
staff wished to have purity standards for its product tightened
so that it becomes the only company able to produce the material
to the new specification, and all smaller competitors were to
be squeezed out.
8. Overall, I am writing to suggest to the
Committee that they are witnessing a failure of the administrative
machine to deal properly with the queston of food supplements
and a quite improper attempt to use spurious toxicological views
to bolster an administrative decision which would otherwise have
no backing. The real and deeper problems must be dealt with properly
by ensuring that consumers are properly informed and yet have
the right to choose to eat odd substances, so long as they are
not misled or exposed to unacceptable degrees of risk as demonstrated
by and assessed by clear-cut open procedures.
9. In conclusion we see that in the case
of vitamin B6 the Minister has been wrongly advised and the draft
regulations should be withdrawn so that a considered view can
be taken of the right way to deal with the sale and labelling
of this vitamin. This should then become part of the wider consideration
of how to deal with food supplements.
2 April 1998
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