The artificial sweetener known as aspartame is composed of two amino acids: phenylalanine and aspartic acid. Aspartame -- also known by its brand names of Equal and Nutrasweet -- is much sweeter than natural sugar and is used in diet sodas such as Diet Coke and Diet Pepsi. While side effects of aspartame are rare, several cases of unwanted effects have been reported. In addition, certain populations may experience more severe side effects.
Cellulitis
The pharmacology reference MicroMedex summarizes several different case reports in which individuals exposed to aspartame in diet sodas developed a condition known as cellulitis. In cellulitis, the skin becomes infected by bacteria. According to MayoClinic.com, this is a serious, potentially life-threatening situation, because the infection can rapidly spread -- both on the skin and into the bloodstream. Fortunately, there have only been case reports of an association between consuming aspartame in diet soda and developing this skin infection. This indicates that such a response is extremely rare.
Hives
The medical term for hives is urticaria. As explained on the National Institutes of Health MedlinePlus website, urticaria often develops as an allergic reaction. The immune system responds to a "trigger" substance -- a food, drink, or chemical -- by releasing a variety of chemicals, including histamine. When histamine is released, one manifestation of this release is hives: raised, red bumps that may be extremely itchy. The summary on aspartame provided by MicroMedex explains that there have been reports of individuals developing hives in response to drinking diet soda containing aspartame. It is important to remember that, as with the side effect of cellulitis, this response to diet soda is a rare and even controversial one. According to the U.S. Food and Drug Administration, aspartame is considered safe for most people based on results of clinical trials.
Effects Related to Phenylketonuria
Phenylketonuria (PKU) is a rare disease that is inherited in an autosomal recessive manner. That is, in order for a baby to be born with this disease, it must inherit two defective copies of a specific gene -- one from each parent. Babies with PKU are unable to correctly process the amino acid phenylalanine; as a result, the levels of phenylalanine in the blood increase to dangerous levels and can cause a variety of complications, including brain damage. Treatment for this disease involves a strictly followed, low phenylalanine diet. Because aspartame contains the amino acid phenylalanine, people with PKU should avoid aspartame. However, if aspartame and other phenylalanine-containing foods are not avoided, people with PKU may notice that their urine, breath and skin take on a strange, "musty" odor. This is an indication that there has been an accumulation of phenylalanine in the body. Fortunately, most states require that newborn babies be screened for this treatable disease; early detection and treatment can help prevent complications such as mental retardation and seizures.
References
- MedlinePlus: Sweeteners
- MayoClinic.com: Cellulitis
- MedlinePlus: Hives
- U.S. FDA: Food Ingredients
- "MicroMedex;" Aspartame; Thomson Reuters Healthcare; 2010
- MedlinePlus: Phenylketonuria
