Published this month in the journal Environmental Health Perspectives, the study, by the European Ramazzini Foundation of Oncology and Environmental Sciences (ERF) in Italy, linked a regular intake of aspartame with an increased risk of leukemia, lymphomas and breast cancer in rats.

Typically, aspartame is commonly used sweetener in the food and soft drink industries, but the revelations could also put a spanner in the pharmaceutical works, as more than 500 pharmaceutical products contain the excipient, many of which are medicines for children.

While the US Food and Drug Administration (FDA) was keeping a cool head about the findings, it had announced it would be reviewing the study.

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

"However, 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."

The study is the second conducted by ERF and aimed to build on the first, published in 2005, which also suggested a link between the sweetener and cancer.

Wrote the researchers: "On the basis of the present findings, we believe that a review of the current regulations governing the use of aspartame cannot be delayed. This review is particularly urgent with regard to aspartame-containing beverages, heavily consumed by children."

Despite the views of the researchers, both the FDA and the European Food Safety Authority concluded after reviewing the first study's data last year that the findings did not provide sufficient evidence to call into question their classification of aspartame as safe for human consumption.

The agencies will now be forced to decide whether aspartame's status has to change based on the new study.

This will be difficult when three animal studies recently conducted by the US National Toxicology Program concluded aspartame had no carcinogenic activity.

Aspartame has been safely consumed for nearly 25 years and has been the subject of more than 200 scientific studies confirming its safety.

The ERF study looked at aspartame doses of 20mg per kg and 50mg per kg, finding that as little as 20mg per kg was enough to suggest a link to increased risk of cancer. The acceptable daily intake of aspartame in the US is 50mg per kg of body weight.