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Eat too much, a cancer you'll get.
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! colspan="2" align=center bgcolor="#cccccc" | Aspartame
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| [[IUPAC nomenclature|Chemical name]]
| align="center" | ''N''-L-α-Aspartyl-L-phenylalanine<br>1-methyl ester
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| [[Chemical formula]]
| C<sub>14</sub>H<sub>18</sub>N<sub>2</sub>O<sub>5</sub>
|-
| [[Molecular mass]] || 294.30 g/mol
|-
| [[Melting point]] || 246 - 247 °C
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| [[CAS registry number|CAS number]] || 22839-47-0
|-
| [[Simplified molecular input line entry specification|SMILES]]
| <small>[NH3+][C@@H](CC([O-])=O)C(N[C@@H]<br>(CC1=CC=CC=C1)C(OC)=O)=O</small>
|-
| colspan="2" align="center" | [[Image:Aspartame_structure.png|Chemical structure of aspartame]]
|}
'''Aspartame''' is the name for the artificial, non-[[carbohydrate]] [[sweetener]], ''Aspartyl-phenylalanine-1-methyl ester''; i.e. the methyl [[ester]] of the [[dipeptide]] of the [[amino acid|amino acids]] [[aspartic acid]] and [[phenylalanine]].
It is 160 times sweeter than [[sugar]] ([[sucrose]] or saccharose), and is marketed under a number of trademarked names, such as '''NutraSweet''', '''Equal''', and '''Canderel'''. It is an ingredient in 5,000 consumer foods and beverages sold worldwide. In the United States aspartame is often found in restaurants in [[blue]] packets. In the European Union it is also known under the [[E number]] (additive code) '''E951'''. It is a common sweetener in prepared foods, particularly [[soft drink]]s. Aspartame is one of the sugar substitutes used by [[diabetes mellitus|diabetics]]. Products containing aspartame usually have a warning label that they contain [[phenylalanine]], in compliance with U.S. [[United States Food and Drug Administration|FDA]] guidelines. Phenylalanine, a natural amino acid found in many foods, is deleterious only to sufferers of the genetic disorder [[phenylketonuria]]. Aspartame, being a [[peptide]], breaks down into its constituent amino acids when heated in the presence of water and acids. Therefore, it is unsuitable for use in baking. However, it is commonly used in diet soft drinks such as [[Diet Coke]] or [[Diet Pepsi]], or to sweeten [[coffee]] and [[tea]].
While aspartame, like other peptides, has a caloric value of 4 kilocalories per gram, the quantity of aspartame needed to produce a sweet taste is so small as to make its caloric contribution negligible, which makes it a popular sweetener for those trying to avoid calories from sugar.
== Discovery and approval ==
Aspartame was discovered in [[1965]] by James M. Schlatter, a chemist working for [[Searle_(company)|G.D. Searle & Company]]. Schlatter had synthesized aspartame in the course of producing an anti-[[ulcer]] drug candidate. He discovered its sweet taste serendipitously when he licked his finger, which had accidentally become contaminated with aspartame.
Initial safety testing suggested that aspartame might cause [[brain tumor]]s in rats; as a result, the [[Food and Drug Administration]] did not approve its use as a food additive in the [[United States]] for several years. In [[1980]], the FDA convened a Public Board of Inquiry (PBOI) consisting of independent advisors charged with examining the purported relationship between aspartame and [[brain cancer]]. The PBOI concluded that aspartame did not cause brain damage, but it recommended against approving aspartame at that time, citing unanswered questions about cancer in laboratory rats. In [[1981]], U.S. President [[Ronald Reagan]] and [[Donald Rumsfeld]] (a CEO of G.D. Searle & Company and friend of Reagan) fired the old FDA Commissioner, and hired a new head of the FDA: Arthur Hull Hayes, a defense department contractor. Hayes approved aspartame for use in dry goods, citing data from a Japanese study that had not been available to the members of the PBOI. [http://www.fda.gov/bbs/topics/ANSWERS/ANS00772.html] In 1983 Hayes was under fire for accepting corporate gifts. He left the FDA and went to Searle's public-relations firm as senior medical advisor. The FDA further approved aspartame for use in carbonated beverages in [[1983]], and for use in other beverages, baked goods, and confections in [[1993]]. In [[1996]], the FDA removed all restrictions from aspartame allowing it to be used in all foods.
In [[1985]], G.D. Searle was purchased by [[Monsanto]]. In this merger, Searle's aspartame business became a separate Monsanto subsidiary, the [[NutraSweet|NutraSweet Company]]. The U.S. [[patent]] on aspartame expired in [[1992]], and the aspartame market is now hotly contested between the NutraSweet Company and other manufacturers, chiefly the [[Holland Sweetener Company]].
== Properties and use ==
At the concentrations used in soft drinks, aspartame is 180 times sweeter than sugar. However, its taste is not quite the same as sugar: aspartame's sweetness has a slower onset and longer duration than sugar's, and some people find an unpleasant off-taste in its flavor. Blends of aspartame with [[Acesulfame potassium]] are purported to have a more sugar-like taste, and to be more potent than either sweetener used alone. Some find the taste of aspartame very unpleasant. It is thought that this taste response is genetic in nature, but so far no studies have been done.
Aspartame's methyl ester group is susceptible to [[hydrolysis]], especially at elevated temperatures. When this happens, its sweet taste is lost. Its stability under heating can be improved to some extent by encasing it in [[fat]]s or in [[maltodextrin]]. Aspartame's 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 [[soda fountain|fountain beverages]], aspartame is sometimes blended with a more stable sweetener, such as [[saccharine]].
In products such as powdered beverages, aspartame's amino group can undergo a [[Maillard reaction]] with the [[aldehyde]] groups present in some artificial flavoring agents. The ensuing loss of both flavor and sweetness can be prevented by protecting the aldehyde as its [[acetal]].
== Health effects ==
Since the FDA approved aspartame for consumption in 1981, some researchers have suggested that a rise in [[brain tumor]] rates in the United States may be at least partially related to the increasing availability and consumption of aspartame. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8939194&dopt=Abstract] In 2005, researchers with the Cancer Research Centre in [[Italy]] reported that aspartame "causes a dose-related statistically significant increase in [[lymphoma]]s and [[leukaemia]]s in female [rats] at dose levels very near those to which humans can be exposed". However, the report also found that "no statistically significant increase in malignant [[brain tumor]]s was observed". [http://www.ramazzini.it/fondazione/docs/AspartameGEO2005.pdf] The study, published in the ''European Journal of Oncology'', raises concerns about the levels of aspartame exposure. [http://news.bbc.co.uk/1/hi/health/4683371.stm]
It has been suggested that aspartame might be a [[neurotoxin]] [http://www.whale.to/a/exposes.html] since one of its labile chemical components is [[methanol]] (wood alcohol), that is converted in the body to [[formaldehyde]]. This is however, unlikely due to the small concentrations required in products. One of the many hypotheses about the causes of [[Gulf war syndrome]] is that [[soldier]]s, after drinking [[gallon]]s of [[soft drink]]s containing aspartame in the extreme heat, accumulated toxic doses of [[methanol]], [[formaldehyde]], [[diketopiperazine]], and [[formic acid]] from the breakdown of the sweetener into its component molecules. The Pentagon once listed aspartame in an inventory of prospective biochemical warfare weapons submitted to Congress. However, the symptoms do not greatly resemble those of classic methanol [[poisoning]], and the body, in its normal metabolism, produces methanol in quantities comparable or greater than would be ingested via aspartame, so this theory does not have wide support.
Questions about aspartame frequently revolve around concerns of health conditions that are allegedly caused by the sweetener, including [[headach]]es, [[seizure]]s, [[allergy|allergic]] reactions, changes in [[mood disorder|mood]] or [[behaviour]], and symptoms similar to [[multiple sclerosis]]. Indeed, an [[e-mail]] has been circulating since [[1998]], claiming to be from a [[lecturer]] at an international conference on aspartame risks, listing various symptoms supposedly caused by the chemical. This email has generally been dismissed as inaccurate, and there is no evidence that such a conference or other events recounted in the email actually occurred. [http://www.snopes.com/toxins/aspartame.asp]
It is worth bearing in mind that aspartame is commonly found in soft drinks containing other components which may cause some side-effects, for example, [[caffeine]].
A large body of scientific evidence suggests that aspartame, even in amounts many times greater than typical consumption, is safe and not associated with adverse health effects. The U.S. Food and Drug Administration has investigated claims of ill effects since [[1982]] and maintains that there is ''no reasonable evidence of possible public health harm'' and ''no consistent or unique patterns of symptoms reported with respect to aspartame that can be causally linked to its use''. [http://www.aspartamearchives.org/archieves/2.php]
Nonetheless, in [[September]] of [[2004]], a [[RICO (law)|RICO]] lawsuit was filed against the [[NutraSweet|NutraSweet Corporation]] and the [[American Diabetes Association]] for manufacturing and promoting the use of aspartame.
== Chemistry ==
Aspartame is the [[methyl]] [[ester]] of the [[dipeptide]] of the [[amino acid]]s l-[[aspartic acid]] and l-[[phenylalanine]]. Under strongly [[acid]]ic or [[Base (chemistry)|alkaline]] conditions, aspartame first splits off [[methanol]] by [[Hydrolysis|hydrolysis]]. Under more severe conditions, the [[peptide bond]]s are also [[hydrolyzed]], resulting in the free amino acids.
== See also ==
* [[Sugar substitute]]
== External links ==
* [http://www.fda.gov/fdac/features/1999/699_sugar.html FDA Article]
* [http://www.aspartame.org/ Aspartame.org] Info from a low-calorie Food & Beverage Industry-supported organization.
* [http://www.aspartamearchives.org Aspartame Archives]
* [http://www.dorway.com/cdctext.txt Criticism of CDC report findings]
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* [http://www.aspartamekills.com/ aspartamekills.com], a highly biased anti-aspartame website.
* [http://europa.eu.int/comm/food/fs/sc/scf/out155_en.pdf Update on the Safety of Aspartame 2002] by the [[European Commission]] Scientific Committee on Food (SCF) (pdf).
* [http://www.greenfacts.org/aspartame/aspartame.htm A summary of the previous report] by the industry [[lobbying]] group [[GreenFacts]].
[[Category:Sweeteners]]
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