A new study links small doses of the popular artificial sweetener aspartame to leukemia, lymphoma and breast cancer in rats.

The U.S. Food and Drug Administration has said it will review the data, but will not rush to judgment on the sweetener, which can be found in the sugar substitutes Equal and NutraSweet, as well as in diet sodas and food.

The study followed a group of 4,000 rats who were given low daily doses of aspartame (comparable to what a dedicated human diet soda drinker might consume) beginning during "prenatal" life, according to a report in the Consumerist.com. The rats were dissected after natural death and the effects of the aspartame calculated.

Click here to read the whole story

The results, published this month in the journal Environmental Health Perspectives, linked regular intake of the sweetener with increased risk of leukemia, lymphomas and breast cancer. It also reported that when exposure to the sweetener starts during fetal life, the potential carcinogenic effects are increased.

The study was the second conducted by the European Ramazzini Foundation of Oncology and Environmental Sciences (ERF) in Italy. Consumer groups are calling on the FDA to immediately review the findings.

The safety of aspartame was first called into question in 2005 when ERF published its first study on the sweetener's link to cancer. After reviewing the data, the FDA concluded last year that the findings did not provide sufficient evidence to call into question their classification of aspartame as safe for human consumption.

In an e-mail to FoodNavigator-USA.com, the FDA said it is, "interested in reviewing the recently published study; however, to date FDA has not been provided the data from this new study. Until FDA conducts an evaluation of the study, it cannot comment on the findings."

The FDA also said in its e-mail that "the conclusions from this second European Ramazzini Foundation are not consistent with those from the large number of studies on aspartame that have been evaluated by FDA, including five previously conducted negative chronic carcinogenicity studies. Therefore, at this time, FDA finds no reason to alter its previous conclusion that aspartame is safe as a general purpose sweetener in food."

The authors of the study claim that current research on the effects of aspartame are based on studies that did not use a large enough sample of animals and did not allow the animals to live out their natural lifespan.

The authors also took issue with a study conducted by the U.S. National Institutes of Health and the American Association of Retired Persons, in which a number of Americans responded to self-administered questionnaires about what they ate and the results compared to their rate of brain cancer.