Toxicology: HEW Bans the Cyclamates

First there was sugar, squeezed from sugar cane and white beets. Dentists blame it for damaging the teeth; it makes people gain weight, and some cardiologists now suspect that its excess use may be a factor in heart-artery diseases. Then, 90 years ago, chemists hit upon saccharin, which is 500 times as sweet as sugar and does not add calories to the diet. But saccharin has the disadvantage of leaving a bitter aftertaste in many people’s mouths, and it cannot be widely used in cooking because it breaks down under heat. When a doctoral chemistry student, Michael

Sveda, accidentally discovered cyclamate sodium (TIME, June 5, 1950), it looked as if the ideal sweetener for people who do not want to get fat had been found: it is 30 times as sweet as sugar, leaves little aftertaste and survives the heat of cooking. In the years since, cyclamates have become the basis of a $1 billion-a-year business.

Last week the Food and Drug Administration condemned cyclamates as possibly dangerous to health and effectively banned their widespread use in the U.S. Robert Finch, Secretary of Health, Education and Welfare, ordered that all foods and drinks containing the artificial sweetener be removed from grocers’ shelves and soft-drink vending channels no later than Feb. 1. In the case of products containing the largest proportions of cyclamates, the deadline is Jan. 1. The effects of this abrupt order on food and drink manufacturing, processing, distribution and marketing will be enormous (see BUSINESS).

Metabolic Variation. As the reason for his ban, Finch cited new evidence that cyclamates cause cancer in animals. At the same time, he emphasized that there is as yet “no evidence that they have indeed caused cancer in humans.” HEW, he said, was being prudent, and will now check other food additives to see whether they may be harmful to human health.

The trouble with cyclamates (besides the sodium compound, there is a calcium combination for patients on low-salt diets) is that they do not behave predictably in the human body—unlike sugar, which is completely and naturally metabolized. Cyclamates break down in the body, forming chemicals, notably cyclohexylamine (CHA). This, in large doses (upwards of 50 times the probable human dose of cyclamate), is known to cause bladder cancer in rats. Because of the emergence of CHA, cyclamates injected into incubating eggs cause grotesque deformities in many of the chicks and kill others in the shell.

Many human beings convert only 1% of their cyclamate intake to CHA, and so minute a quantity might well be harmless. But for unknown reasons other, equally “normal” people convert as much as 40% to CHA; if they are heavy users of cyclamates, the resulting high dose of CHA might cause cancer or other diseases. Like countless other chemicals, cyclamates also cause breaks in the chromosomes of both man and animals, but the genetic significance of these breaks is not yet known.

It is impossible to single out the high-risk, high-CHA converters, or to regulate the cyclamate intake of free-living human beings. So Finch saw no safe middle course and concluded that he had to impose a flat ban. Exceptions will be made for diabetics and those on reducing diets under doctor’s care, for whom cyclamates will be available on prescription. For the rest, it will be back to sugar or saccharin.