Is the artificial sweetener aspartame really safe to consume?

Aspartame

Aspartame is an artificial non-saccharide sweetener 200 times sweeter than sucrose and is commonly used as a sugar substitute in foods and beverages. It is a methyl ester of the aspartic acid/phenylalanine dipeptide with brand names NutraSweet, Equal, and Canderel. Aspartame was approved by the US Food and Drug Administration (FDA) in 1974, and then again in 1981, after approval was revoked in 1980.

Aspartame is one of the most studied food additives in the human food supply. Reviews by over 100 governmental regulatory bodies found the ingredient safe for consumption.

Aspartame is around 180 to 200 times sweeter than sucrose (table sugar). Due to this property, even though aspartame produces 4 kcal (17 kJ) of energy per gram when metabolized, the quantity of aspartame needed to produce a sweet taste is so small that its caloric contribution is negligible. The sweetness of aspartame lasts longer than that of sucrose, so it is often blended with other artificial sweeteners such as acesulfame potassium to produce an overall taste more like that of sugar.

Like many other peptides, aspartame may hydrolyze (break down) into its constituent amino acids under conditions of elevated temperature or high pH. This makes aspartame undesirable as a baking sweetener and prone to degradation in products hosting a high pH, as required for a long shelf life. The stability of aspartame under heating can be improved to some extent by encasing it in fats or in maltodextrin. The stability when dissolved in water depends markedly on pH. At room temperature, it is most stable at pH 4.3, where its half-life is nearly 300 days. At pH 7, however, its half-life is only a few days. Most soft-drinks have a pH between 3 and 5, where aspartame is reasonably stable. In products that may require a longer shelf life, such as syrups for fountain beverages, aspartame is sometimes blended with a more stable sweetener, such as saccharin.

Descriptive analyses of solutions containing aspartame report a sweet aftertaste as well as bitter and off-flavor aftertastes.

Sugar substitute

The artificial sweetener aspartame has been the subject of several controversies since its initial approval by the U.S. Food and Drug Administration (FDA) in 1974. The FDA approval of aspartame was highly contested, beginning with suspicions of its involvement in brain cancer, alleging that the quality of the initial research supporting its safety was inadequate and flawed, and that conflicts of interest marred the 1981 approval of aspartame, previously evaluated by two FDA panels that concluded to keep the approval on hold before further investigation. In 1987, the U.S. Government Accountability Office concluded that the food additive approval process had been followed properly for aspartame. The irregularities fueled a conspiracy theory, which the "Nancy Markle" email hoax circulated, along with claims—counter to the weight of medical evidence—that numerous health conditions (such as multiple sclerosis, systemic lupus, methanol toxicity, blindness, spasms, shooting pains, seizures, headaches, depression, anxiety, memory loss, birth defects, and death) are caused by the consumption of aspartame in normal doses.

Aspartame is a methyl ester of the aspartic acid/phenylalanine dipeptide. Potential health risks have been examined and dismissed by numerous scientific research projects. With the exception of the risk to those with phenylketonuria, aspartame is considered to be a safe food additive by governments worldwide and major health and food safety organizations. FDA officials describe aspartame as "one of the most thoroughly tested and studied food additives the agency has ever approved" and its safety as "clear cut." The weight of existing scientific evidence indicates that aspartame is safe as a non-nutritive sweetener.