Sweet dreams.

In 1970 the Food and Drug Administration banned the artificial sweetener cyclamate. For more than a decade, until the arrival of aspartame (Nutra-Sweet), dieters with sweet tooths had to put up with the wrenching aftertaste of saccharin.

The FDA's cyclamate decision was based on a 1969 study in which rats who were fed high doses of the sweetener developed cancer. The World Health Organization, the U.N. Joint Committee on Food Additives, and the National Academy of Sciences have since rejected that study as a fluke because its results could not be reproduced. Yet cyclamate remains illegal.

A recent report from the American Council on Science and Health cites the cyclamate episode as an example of the FDA's foot-dragging approach to artificial sweeteners. Not only has the original cyclamate study been discredited, but other fears about the sweetener have also proven ill-founded.

Concerns that the additive works with other substances to cause cancer stemmed from experiments in which chemicals were surgically implanted in animals' organs--a highly artificial procedure that does not correspond to the way that people are exposed to the chemical. Standard tests find that cyclamate is not mutagenic, and it does not raise blood pressure when fed to humans or animals.

At extremely high levels, cyclohexylamine, an occasional metabolic product of cyclamate, causes rats' testicles to shrink. (Cyclamate itself does not.) Based on these studies, researchers calculated an acceptable level for human consumption, dividing the dose at which effects first appear by 100. This level, 11 mg per kg of body weight every day, amounts to a daily dose of about 1.7 pounds for someone weighing 150 pounds.