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]]]]]]]] U.S. Expected to Lift Ban On Cyclamate [[[[[[[
Sweetener Harmless, Most Experts Say
By Malcolm Gladwell
Washington Post Staff Writer
[From The Washington Post, 16 May 1989, p. A1:6]
[Kindly uploaded by Freeman 10602PANC]
Federal health officials, who banned the artificial sweetener
cyclamate 20 years ago in the midst of one of the biggest health
scares of the 1960s, are now widely expected to reapprove it,
possibly this year. Once accused of causing everything from
bladder cancer to birth defects, cyclamate is now widely thought
to be harmless.
``I have no reluctance in saying that with cyclamate we made a
mistake,'' said Robert Scheuplein, acting director of the office
of toxicological services for the FDA's Center for Food Safety
and Applied Nutrition.
A group of monkeys at the National Cancer Institute provides
evidence of the mistake. Each of them has been fed the amount of
cyclamate that would sweeten 30 cans of diet soda every day, five
days a week, for the past 17 years.
In February, the institute issued its first progress report:
the monkeys are doing just fine.
After two decades of legal and regulatory controversy, scores
of cancer and toxicology studies and heated scientific debate,
the jury on cyclamate is in.
The agency's reversal on cyclamate promises to add to the
growing public debate about how government health officials
evaluate potential health risks. According to scientists and
industry officials involved in the controversy, the evidence
exonerating cyclamate was available years ago and the fact that
the agency took two decades to concede its mistake shows how
large a role politics can play in decisions presented as
scientific.
Even some government officials concede that the long and often
bizarre story of the chemical is an example of how a system
designed to separate real from imagined risks broke down.
Cyclamate was one of the world's most widely used artificial
sweeteners when, in the late 1960s, its safety became a matter of
public concern. In 1969, following the completion of a study by
a New York laboratory showing that some rats with cyclamate
pellets implanted in their bladders were developing tumors, the
FDA restricted the sale of the chemical. The following year,
under pressure from Congress, the agency banned it entirely.
From the beginning, the ban was controversial. Referring to
the ``farcical progress'' of the cyclamate veto ``bandwagon,''
the British scientific journal Nature ridiculed that FDA
decision, calling the evidence indicting cyclamate ``about as
solid as candy floss.''
One problem, for example: The method of surgically implanting
cyclamate pellets in rats -- as opposed to feeding them the
chemical -- was one the National Academy of Sciences had rejected
that same year as not analogous to the way humans are exposed to
cyclamate.
Over the next few years, 10 more experiments were conducted on
rats, seven on mice, one on hamsters, one on beagles, and two on
monkeys -- all in an attempt to replicate the original New York
study. None could. The scientist who headed up the one damning
experiment renounced it. Numerous countries that had followed
the U.S. lead on banning cyclamate reapproved it.
The FDA, however, stood firm. In 1980, seven years after the
manufacturer of cyclamate, Abbott Laboratories, filed for
reapproval of cyclamate, the agency emphatically denied the
request. Only today, seven years after Abbot filed again for
reapproval, after two dozen long-term cancer studies, more than
70 experiments looking for genetic damage, hundreds of other
toxicological studies, and exhaustive and positive reviews of the
chemical by the National Cancer Institute and the National
Academy of Sciences, is the FDA apparently comfortable with
reapproving the chemical.
According to many of the scientists and industry officials
involved with cyclamate, the FDA's long delay in acknowledging
the new evidence raises troubling questions about the way in
which the agency assesses suspected carcinogens.
One concern is over the way that politics -- not science --
appeared to play the lead role in the evaluation of cyclamate.
``The matter was taken out of the hands of the scientists here
and handled by attorneys.'' said Scheuplein of the agency's 1980
decision not to reapprove the sweetener. ``Meetings were not
held. Things were not pursued. Work was not done. The people
who were involved at the time were inadequate to the job.''
``It was just politics,'' said Elizabeth Weisberger, the now
retired assistant director for chemical carcinogens at the
National Cancer Institute. ``Once the decision was made, no one
wanted to reverse it. It would have meant a loss of face.''
In a strongly worded letter to the FDA after the 1980
decision, the American Statistical Association said the arguments
used to reject cyclamate amounted to an ``extreme
misrepresentation of our professional methodology'' and routinely
used methods ``foreign to everything that is taught in the
statistics profession.''
``We strongly encourage you to have the appropriate
professionals prepare a new statement that correctly expresses
the statistical principles that are involved in this issue,'' the
latter said. ``This new statement is needed to avoid the
ridicule of knowledgeable scientists including those in your
organization. FOR THESE REASONS WE BELIEVE THAT A REVISION MUST
BE PUBLISHED IN THE FEDERAL REGISTER AS A CORRECTION. [emphasis
is theirs]''
The group's arguments centered on interpretation of what
statisticians call ``p'' values, a measure of the probability
that an experimental result could have happened by chance and not
because of the thing being tested, cyclamate in this case, alone.
The p value is calculated from the size of the experimental and
control groups. Typically scientists do not accept results as
statistically significant if there is greater than a 5 percent
chance that the observed differences between two groups could be
a chance occurrence.
In the 1980 cyclamate decision, however, the FDA routinely
interpreted as significant experiments with high p values,
including one study with very few tumors where the chances of a
spontaneous tumor development was 20 percent.
What the agency's actions reflected, according to many within
the scientific and regulatory community, is the extreme
conservatism that public and congressional pressure has demanded
from the FDA on issues involving cancer risk.
According to the FDA's congressional mandate, for example, the
agency is not allowed to approve any substance that is known to
cause cancer in animals. The effect of this, though rarely
invoked explicitly by the agency, has been to turn mouse and rat
studies into a ``gold standard'' for carcinogenicity, even though
new scientific evidence has increasingly cast doubt on whether
giving mice or rats massive doses of a chemical is actually an
effective way of predicting the cancer-causing potential of the
same compound in humans.
In the case of cyclamate, many scientists and regulators say
that holding the sweetener to such a standard made it impossible
to overturn the FDA's prior decision to ban.
[The following is not part of the original article.]
Edith Efron. The Apocalyptics: How Environmental Politics
Controls What We Know About Cancer. New York: Simon &
Schuster, Inc., 1984.
William R. Havender. Of Mice and Men: The Benefits and
Limitations of Animal Cancer Tests. New York: American
Council On Science and Health, August 1984.
Lester B. Lave, et al. ``Information Value of the Rodent
Bioassay'', Nature 336, p. 631-633 (15 December 1988).
(``Tests for human carcinogens using lifetime rodent bioassaysays
are expensive, time-consuming and give uncertain results. For
most chemicals such tests are not cost-effective.'')
* * *
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