As of March 2015, the only health danger consistently connected to aspartame is possible abnormal brain development in people who have phenylketonuria, a rare genetic disorder, according to the American Cancer Society. Aspartame has not been found to cause cancer, brain tumors, leukemia, lymphoma or other dangers to human health.
In 2007, after reviewing findings of a large number of studies, the U.S. Food and Drug Administration reissued its earlier conclusion that it is safe to use aspartame as a general-purpose food sweetener, states the American Cancer Society.
In 2009, a panel report of the European Food Safety Authority, which evaluated whether aspartame was safe for use in the European Union, concluded there was no evidence aspartame had the potential to cause cancer or cell damage. Aspartame remains approved for use in the European Union, according to the American Cancer Society.
A person with phenylketonuria, usually diagnosed with a blood test at birth, is unable to break down the amino acid phenylalanine. Many foods contain phenylalanine. When it builds up in the blood, phenylalanine prevents the brain from receiving other essential amino acids. Children with phenylketonuria suffer abnormal brain development if their phenylalanine intake is not significantly limited, according to the American Cancer Society.
Aspartame contains phenylalanine, so people with phenylketonuria must limit their intake of aspartame. A product that contains aspartame, including medicine, has a printed warning to phenylketonurics that the product contains phenylalanine, states the American Cancer Society.