The final report of a seven-year study on aspartame (also known as Nutra-Sweet or Equal) has linked it to high rates of lymphomas, leukemias, and other cancers in rats. The rats were given the equivalent of four to five bottles of diet soda a day for a human.
The carcinogenic effect of aspartame was found at levels as low as 400 parts per million, or about 20 milligrams a day for humans. This is far less than current daily limits in America (50 milligrams) and the UK (40 milligrams).
When the initial findings were released almost a year ago, they were met with criticism from artificial sweetener trade groups, and support from groups critical of aspartame.
No government regulatory agency has yet acted on the findings; there have been calls for a ban in Britain, and the European Food Safety Authority has begun a review of the study's results. United States FDA officials have said that they also intend to conduct a review.