The title of a new study conducted at the Ramazzini Institute and published in the American Journal of Industrial Medicine does not reflect the conclusion of the study research team itself. The authors of the article, “Aspartame administered in feed, beginning prenatally through life span, induces cancers of the liver and lung in male Swiss mice,” conclude that aspartame is not the culprit but its metabolites, specifically methanol. This is especially interesting since methanol is a natural and harmless breakdown product of many commonly consumed foods. Aspartame is composed of two amino acids, aspartic acid and phenylalanine, as the methyl ester. Amino acids are the building blocks of protein. Aspartic acid and phenylalanine are found naturally in protein containing foods, including meats, grains and dairy products. Methyl esters are also found naturally in many foods, such as fruits and vegetables and their juices. The methanol produced during the digestion of aspartame is identical to that which is provided in much larger amounts from many fruits, vegetables and their juices and is part of the normal diet. In fact, a glass of tomato juice provides about 6 times as much methanol as an equivalent amount of diet beverage sweetened with aspartame. Regardless of the source, after methanol is formed it is further broken down through normal body processes. Numerous scientific studies have shown that the amount of methanol one could consume from aspartame-containing foods and beverages could not reach harmful levels.
Furthermore, in June 2010, the U.S. Environmental Protection Agency (EPA) announced it was suspending further action on its health assessment of methanol pending additional review of research conducted by the Ramazzini Institute (RI). In January 2010, EPA released its draft health assessment of methanol under the Integrated Risk Information System (IRIS) proposing to classify methanol as a “likely human carcinogen” based almost entirely on data from the Ramazzini Institute. In April 2010 a team of pathologists from the National Toxicology Program (NTP) visited Italy, completed a partial review of Ramazzini’s methanol study and reported that further reviews are necessary to support or refute the overall conclusions of the study. The following statement is included in NTP's recommendations: "The presence of inflammatory lesions in several tissues is consistent with chronic infection, which we understand is commonly observed in aging rats in the lifespan studies carried out by the RI. In addition, the practice of allowing animals to die spontaneously can lead to significant autolysis of some tissues. It is recommended that the RI take steps to minimize these factors in the conduct of future studies."
The Ramazzini Institute does not follow the internationally established protocol for animal carcinogenicity studies, as reflected in the EPA comment above. An extensive independent peer-review of the Ramazzini histopathology slides has not been conducted, as it would have been for carcinogenicity studies performed for regulatory submission. There is no evidence that any Ramazzini studies were ever examined by an inside or outside group for compliance with Good Laboratory Practices (GLP) or that any Standard Operating Procedures (SOP) were written or followed.
In studies in Swiss mice, it is common knowledge that males have a higher incidence of liver and lung tumors. In fact in the Ramazzini aspartame study in Swiss mice, the incidence of liver and lung tumors in all male (control and treated) groups was less than the historical control range reported in this paper for the Ramazzini Institute. This observation raises serious questions about the conclusions made by the authors of this study.
In fact, according to the 2010 report of NTP pathologists, they arrived at the Ramazzini Institute on April 16, 2010 and the “RI recently received certification by the Organization for Economic Cooperation and Development (OECD), to conduct Good Laboratory Practice (GLP) studies.” Clearly, the Ramazzini Institute did not have GLP certification when the aspartame mouse study was conducted or when other Ramazzini studies were conducted prior to GLP certification in early 2010.