Toxicology: Low-Calorie Sweeteners

There are so many weight watchers and calorie counters in the U.S. that each year they consume almost 1,500 tons of saccharin and 7,500 tons of cyclamates. The cyclamates come in liquid form or in tablets for use at home, and are dissolved in most low-calorie soft drinks by their makers. Are they safe? For years, the U.S. Food and Drug Administration thought so and recommended no limit on consumers' intake.

Last month, Food and Drug had a slight change of heart. On the strength of a report by a special committee of the National Academy of Sciences-National Research Council, the FDA took down the "no limit" sign and suggested that adults should keep down their consumption to five grams a day. For those using only the tablets, this should be no problem, since virtually all of them contain only .05 gm. cyclamate. The safety ceiling would therefore be 100 tablets a day. With the soft drinks, the problem is trickier. Their cyclamate content varies, but it ranges up to about one gram in a 12-or 16-oz. bottle or can. Since the FDA recommends that a 60-lb. child's intake not exceed 1.35 gm. daily, this means that two bottles of low-calorie pop could put him over the top.

Research to date has revealed no serious harmful effects of cyclamates in man. But far more interesting than what the FDA said was what it did not say. It made no mention of recent studies in its own laboratories in which a product of cyclamate metabolism, cyclohexylamine, causes breaks in the chromosomes of cells grown in the test tube. Injections cause similar damage to the chromosomes of rats. In terms of effects upon chromosomes in human beings—and therefore, upon future generations—no one knows just what this means. No matter how hard and fast the geneticists try to work, it may take years to find the answer.