| Metabolism Saccharin, and acesulfame K both go directly through the human digestive system. Therefore, the calories in saccharin are not absorbed, and saccharin can be constituted as an artificial sweetener. But, aspartame is broken down by the body. The body initially breaks down aspartame into its three main substances (phenylalanine, aspartate, and methanol). The phenylalanine, and aspartate are absorbed easily by the stomach and small intestine enzynmes, while the methanol goes directly to the liver. The phenylalanine is broken down into tyrosine, another amino acid. But, the genetic disorder, phenylketonuria (PKU) makes it impossible for the phenylalanine to change into tyrosine. The buildup of phenylalanine causes mental retardation. It is for this reason that products containing aspartame warn pregnant women, and people with PKU not to use their product. Normally, in high amounts methanol is very dangerous to the liver. But, since there is not very much methanol by weight (10%) in aspartame, the methanol is not harmful to the human liver. |