In May 2006, the European Food Safety Authority (EFSA) unequivocally rejected claims by Morando Soffritti of the Ramazzini Institute alleging that aspartame was unsafe. On 13 April 2007, Dr Soffritti made further allegations and claimed to have conducted a second rat study on aspartame.

The following points need to be taken into account when evaluating claims about aspartame safety by the Ramazzini Institute:

• The Ramazzini Institute has not submitted its findings to independent review by other scientists before making its allegations public.
• The laboratory at which the Ramazzini work is conducted does not follow internationally recognised Good Laboratory Practice (GLP) procedures. The rat colony is inbred and is not germ-free.
• The Ramazzini Institute does not reveal the source of its funding.
• The Ramazzini Institute refuses to provide government regulators with full access to its results. For example, only 70 pathology slides were provided to EFSA following the first Ramazzini rat study on aspartame in 2005. This compares with approximately 39,000 slides from carcinogenicity studies on aspartame that were independently reviewed before aspartame was first approved.
• The quality of work at the Ramazzini Institute has been criticised by the United Kingdom Department of Health Committee on Carcinogenicity, by the French food safety agency (L'Agence Francaise de Sécurité Sanitaire des Aliments), by the European Food Safety Authority, and by the United States Food and Drug Administration (FDA).
• There is an extensive body of data from human studies that supports the safety of aspartame. For example, in 2006 the United States National Cancer Institute published the results of a five year study of over 500,000 people which concluded that there was no link between aspartame and leukemias, lymphomas or brain tumours.
• A comprehensive review of every scientific study ever conducted on aspartame, published in the September 2007 edition of Critical Reviews in Toxicology, reaffirmed the safety of the sweetener. A panel of internationally renowned experts in relevant scientific disciplines reviewed more than 500 studies, articles and reports on aspartame, concluding, "The weight of existing evidence is that aspartame is safe at current levels of consumption...No credible evidence was found that aspartame is carcinogenic, neurotoxic, or has any other adverse effect on health."
• Aspartame is one of the most thoroughly tested ingredients in the food supply and has been approved by the European Food Safety Authority, by the United States Food and Drug Administration, by experts of the United Nations Food and Agriculture Organization and the World Health Organization, and by regulatory agencies in more than 100 countries.
• Aspartame is made from two amino acids, the building blocks of protein that are found in many everyday foods such as meat, fish, cheese, eggs and milk. Aspartame is digested by the body to very small amounts of common dietary components. Aspartame cannot, therefore, cause adverse effects.
• The Ramazzini Institute's scaremongering about aspartame is not benign. By providing an excellent sweet taste without the calories of sugar, aspartame makes a useful contribution to a healthy, calorie-controlled diet and can help people to avoid overweight and obesity, and their associated diseases. Using bad science in an attempt to unsettle people about a safe and beneficial food ingredient can have public health consequences.

25 November 2008