Aspartame, a sweetener found in many consumer foods and soft drinks, has been given the all-clear by the European Food Safety Authority (EFSA). The EFSA panel on food additives, flavourings, processing aids and materials in contact with food (AFC) conducted an evaluation of the sweetener in response to research findings published in 2005 by the European Foundation of Oncology and Environmental Sciences 'B. Ramazzini', which claimed that aspartame can cause cancer. In its published opinion, the AFC panel concluded that, on the basis of all currently available evidence, there is no need to revise current guidelines on the use and consumption of the sweetener, the acceptable daily intake (ADI) of which stands at 40mg/kg body weight. Commenting on the AFC panel's risk assessment, Dr Herman Koëter, EFSA Acting Executive Director, stated: 'EFSA considers that the results of this new study on aspartame do not provide a scientific basis for reconsidering its use in foods.' Aspartame (APM), also known in Europe as E951, is a widely used artificial sweetener consumed by hundred of millions of people around the world. It is found in more than 6,000 products, including soft drinks, chewing gum, sweets, yoghurt, table-top sweetener and some pharmaceuticals such as vitamins and sugar-free cough drops. While aspartame has passed numerous safety evaluation tests, since the time of its introduction onto the market in 1965, it remains a controversial substance. In a long-term study, the European Ramazzini Foundation administered aspartame with feed to eight-week old male and female rats until their spontaneous death. It found 'statistically significant' dose-related increases of cancers such as lymphomas and leukaemia, malignant tumours of the renal pelvis in female rats and malignant tumours of peripheral nerves in male rats. These results, the foundation claims, demonstrate for the first time that aspartame is a carcinogenic agent, capable of inducing malignancies at dose levels lower than the current acceptable daily intake for humans. However, according to EFSA, these findings are flawed. It says that the scale of the study alone in terms of time, number of animals used and doses prescribed, were over and above conventional carcinogenicity studies, and therefore had the potential to be more sensitive to low incidence effects. Also, a high background incidence of chronic inflammatory disease in the lung and other organs was observed in all the groups, including those rats which did not receive the sweetener. The AFC panel concluded that the chronic inflammatory disease was the likely cause for the increased incidence of cancers, not the intake of aspartame. With regard to the findings of cancer in the kidneys, ureter and bladder of rats fed the sweetener, the AFC panel noted that these were likely to be the result of irritation or imbalances in calcium metabolism specific to rats, and therefore of no relevance to humans. Responding to the AFC panel's comments, Scientific Director of the European Ramazzini Foundation and primary author of the aspartame study Dr. Morando Soffritti noted that 'what the panel considers shortcomings of the study are instead distinctive and positive characteristics of our research protocol, research which has provided the scientific basis for changes in international regulations numerous times over the last 30 years. 'The [...] study design closely mirrors the human condition in which persons may be exposed to agents in the industrial and general environments from embryonic life until natural death. Since 80 per cent of cancer is diagnosed in humans over the age of 55, it is of paramount importance to observe how an agent affects laboratory animals in the last third of their lives,' he added. In a press statement, the foundation announced that it will conduct additional research, not only on aspartame, but also on other widely diffused artificial sweeteners and blends used in thousands of foods, beverages and pharmaceutical products. 'International agencies like EFSA will continue to be our first point of reference and we will continue to keep them informed of our results in a timely manner as always,' said Dr. Soffritti. For its part, EFSA says that it will continue to monitor the situation. 'If any new information would become available in the future, EFSA will review these as a matter of priority,' said Dr Koëter.