http://www.acnem.org/journal/20-2_august_2001/editorial.htm
[miscellaneous/page_header.htm]
|
|
. |
Editorial |
|
Ian Brighthope MB, BS, DipAgrSc, MATA, FACNEM
Another study on vitamin C and the common cold has just passed my desk,
immediately followed by phone calls from others who have read it, calling the
work "shonky" and "shoddy". If they mean by this dishonest,
unreliable, trashy, shabby and poor quality, it must be compelling reading.
Compelling in as much as an immediate rebuttal is of paramount importance.
The paper I refer to is titled "Megadose Vitamin C in the Treatment of
the Common Cold: a Randomised Controlled Trial" by Audera, C et al., MJA
Vol 175, 1 October 2001:359-62. I will start with the Conclusion, states that
"Doses of vitamin C in excess of 1 g daily taken shortly after onset of a
cold did not reduce the duration or severity of cold symptoms in healthy adult
volunteers when compared with a vitamin C dose less than the minimum
recommended daily intake.
This study is ill-conceived, poorly designed, methodologically flawed and
mischievously misleading for a number of reasons.
Firstly, the dose of 1 gram three times a day is too small to achieve a
therapeutic effect. This is not megadose as it represents the level of
vitamin C intake which could be achieved with a special diet. Mega is the
prefix to describe something very large or huge and in this context a megadose
of vitamin C is regarded as a dose greater than that which can be obtained
naturally. The literature refers to megadoses of vitamin C as being in the
order of tens of grams, commencing at about 10 grams per day (e.g. a "10
gram" cold, a "20 gram" flu etc.) To use the term mega and apply
it to 1 g is misleading a clearly indicates the authors have failed to review
the broad body of literature on mega vitamin C therapy.
Another massive mistake was the author’s instructions to the participants to
make their own diagnosis of a cold. Many of the symptoms the participants were
to consider for the diagnosis could be related to other conditions e.g.
scratchy throat and trauma, nasal congestion and allergy, stinging eyes and
chemical imitation, muscle aches and enterovirus, fever and some other infection
etc. Self-diagnosis is very unreliable for a ‘scientific experiment’.
Compounding this error was the instruction to commence vitamin C therapy
only after "4 hours of certainty that a cold is coming on". This
would be regarded as incompetent practice by the College and a practitioner
suggesting this as negligent in their duty to the patient. Vitamin C should be
taken at 5-10 gram doses immediately symptoms of a cold or flu commence and
continue every 2-4 hours until symptoms cease or a looseness of the bowel
occurs, indicating sufficient intake. To wait for 4 hours allows the virus,
which may have already been in the system for a number of hours before onset of
symptoms, to fully establish itself and make the task of any therapeutic agent
far more difficult. To further destroy the validity of this trial and the
credibility of its authors, the participants on average waited for 13 hours
between time of symptom onset and vitamin C use. The proper and correct
teaching is "teaspoon dose immediately".
The duration of treatment (3 days), had the initiation time and dose been
correct, was also too short and would have contributed to a negative outcome.
As mentioned earlier, the reliance of the study on self-diagnosis is not
good science and this is amplified by the study’s dependence on participant
self-reporting including all the outcome data.
It would have been very helpful and contributed more to scientific credulity
if the authors had measured vitamin C levels before and during the trial to
determine baseline status and therapeutic levels. This is important in studies
of this nature as it has been documented in other studies in which participants
may have access to active drugs (vitamin C) that the placebo arm has been
confounded by active self-medication.
And what reason did the authors give to explain why 55% of the participants
in the active groups and 57% in the placebo group took other medications for
symptoms. What were those medications? Surely if more than half the
participants in both groups are taking other medications, the
"controlled" nature of the trial has to be seriously questioned.
There were a total of 323 volunteers in the study and responses obtained
from 149 (46%). What happened to the other 174? Why did 54% of participants not
return their event cards? Could it be that this significant proportion was more
compliant, took their vitamin C earlier, failed to develop significant
symptoms, conclude that they may not have caught a real cold and therefore
decide that they would not fit the trial as a cold sufferer consequently
discarding their "event cards". A possibility.
The authors admit to a socio-economic bias selecting healthy staff and
students from the Australian National University and the other weakness in the
study that they failed to reach the target of 75 colds in each treatment group.
According to the literature and even these authors by their own admission,
the Cochrane collaboration has shown a relatively consistent trend for those
taking prophylactic doses in excess of 1 gram daily (most studies 2-8 gram) to
experience some reduction in duration or severity of colds. Here we talk about
prophylactic doses (2-8 gram), while therapeutic doses may be as high as 50-60
gram.
I have quoted Richard Smith, the editor of the British Medical Journal, many
times. He has written - "Only 5% of published articles reach minimum
standards of scientific soundness and clinical relevance. The studies reported
in most medical journals around the world are not of sufficient calibre nor
sufficiently wide in their scope to serve as the foundation stone of
evidence-based medicine."
This study, in my opinion, should never have been published. It will be
quoted by many as another study unsupportive of vitamin C and the common cold.
Its gross weaknesses will be ignored or de-emphasised. It is a study
ill-conceived and designed by researchers who apparently have been peremptorily
dismissive of the volumes of literature endorsing high dose vitamin C
immediately symptoms occur, or moderate doses during epidemics as prophylaxis.
A single negative medical study should not detract from the massive body of
scientific evidence supporting vitamin C therapy.
It is high time to question the value of research into nutritional
therapeutics by ill-informed and unqualified, inexperienced researchers.
I have recently spent some time in Canberra as part of the Complementary
Healthcare Council’s Task Force for the roll-back of GST on CHPs. Presently, I
can advise you that an excellent submission has been given to the appropriate
minister and bureaucrats. Much of this hard work was done by Dr. Mark Donohoe
in conjunction with the CHC and Price Water House Coopers. We will continue to
lobby to achieve a level playing field with pharmaceuticals in the GST-free
health area.
Please always ensure that you prescribe vitamin C at the proper time with
the correct dose by the most effective route for the individual patient with a
particular condition under the appropriate circumstances.
Remember, individuality is a crucial factor in nutrition and this is what
differentiates you from the common garden variety dietician.
Yours in health,
Intelligently,
Dr. Ian Brighthope
President.
The above Editorial will appear in Journal of
the Australasian College of Nutritional & Environmental Medicine, Vol.
20, No. 2, August 2001, page 2 (currently at the printers. The Editorial
is reproduced here with permission of the author. Copyright in the
article vests with ACNEM.
|
|
A full reprint of this
Editorial is also available from ACNEM on request. |
[Last updated Wednesday, 17 October 2007] ALL INFORMATION, DATA, AND
MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR GENERAL INFORMATION
PURPOSES ONLY AND IS NOT TO BE CONSTRUED AS REFLECTING THE KNOWLEDGE OR
OPINIONS OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED AS PROVIDING
MEDICAL OR LEGAL ADVICE. THE DECISION WHETHER OR NOT TO VACCINATE IS AN
IMPORTANT AND COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU ALONE, IN
CONSULTATION WITH YOUR HEALTH CARE PROVIDER.
[miscellaneous/page_footer.htm]
[miscellaneous/page_footer.htm]