Controversia acerca del aspartamo

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La controversia acerca del aspartamo ha sido el tema de una viva controversia pública con respecto a su seguridad y de las circunstancias alrededor de su aprobación. Algunos estudios han recomendado la investigación adicional en la conexión posible entre el aspartamo y las enfermedades tales como tumores cerebrales, lesiones del cerebro, y linfoma. Estos resultados, combinados con notables conflictos de interés en el proceso de la aprobación, han engendrado el activismo vocal con respecto a los posibles riesgos del aspartamo.

Tabla de contenidos 1 Efectos Conocidos 1.1 Metanol y formaldehido 1.2 Phenilalanina 1.3 Aspartic acid 1.4 Aspartylphenylalanine diketopiperazine 2 Responses 3 Recently-published research 4 See also 5 Enlaces externos 5.1 Films 5.2 Websites: Pro-aspartame 5.3 Websites: Anti-aspartame 5.4 News & General Articles 6 Books 7 References

[editar] Efectos Conocidos

En 1995, el jefe de la rama de epidemiología Thomas Wilcox del FDA divulgó que las quejas del aspartamo representaron el 75% de todos los informes de reacciones adversas a las sustancias en el suministro de alimentos a partir de 1981 a 1995. Las preocupaciones por el aspartamo giran con frecuencia alrededor de síntomas y de las condiciones de salud que supuestamente están causadas por el dulcificante. Un total de 92 síntomas y condiciones de salud distintos aparecieron en informes de médicos y consumidores.

Se han planteado dudas en relación a cáncer cerebral, linfoma, y efectos genotóxicos tales como reticulaciones de las proteínas del ADN, pero estas dudas no se basan mayoritariamente en casos clínicos.

Las fuentes para los síntomas y las condiciones divulgados de la salud que han planteado preguntas incluyen:

1. Informes y análisis de antecedentes en diarios científicos y en las conferencias médicas
2. Los síntomas divulgaron al FDA y a otras agencias gubernamentales
3. Los síntomas divulgaron a las organizaciones no gubernamentales, a los investigadores, y a los médicos
4. Informes de síntomas y de condiciones de la salud en los medios
5. casos Uno mismo-divulgados en el Internet.

Hay discusión en la comunidad científica y médica si estos síntomas están o no son causados por la exposición a corto plazo o a largo plazo al aspartame. Algunos estudios humanos y animales han encontrado los efectos nocivos y algunos no han encontrado ningún efecto nocivo. No sólo los resultados de la investigación se han preguntado que, pero el diseño de la investigación que eso condujo a los resultados específicos. Por ejemplo, en la investigación humana del aspartame, el aspartame se proporciona generalmente en cápsulas lento-que disuelven. Pero la concentración en la sangre de injerir el aspartame en cápsulas lento-que disuelven es mucho más baja que ésas de injerir el aspartame líquido (por ejemplo en las bebidas carbónicas).

Algunos estudios humanos proporcionan más que el subsidio diario del aspartame, pero en una forma encapsulada. De acuerdo con la investigación susodicha, la cantidad equivalente de aspartame “del mundo real” en estos estudios humanos sería menos. Otras preguntas que se han planteado sobre la investigación del aspartame que implicaba la longitud de los estudios, el número de los temas de prueba, el conflicto de las ediciones del interés, y métodos de prueba incorrectos.

Los efectos de salud adversos posibles del excedente del discusión se han centrado principalmente en cuatro componentes químicos de aspartame:

[editar] Metanol y formaldehido

Ha habido una cierta preocupación que el metabolismo del aspartame produce el metanol. Este metanol se distribuye a través del cuerpo, se desdobla rápidamente en el formaldehído y el ácido fórmico, y se va a la producción energética. Se cree que el metabolismo del aspartame no daña el cuerpo porque: (a) la cantidad de metanol producida es demasiado pequeña como para interrumpir procesos fidiológicos normales; (b) el metanol y el formaldehído son subproductos naturales del metabolismo humano y son procesados con seguridad por varias enzimas; y (c) hay más metanol en algunos zumos y bebidas alcohólicas de fruta naturales que el que se deriva de la ingestión del aspartame.

Algunos dicen que (a) los zumos de fruta y las bebidas alcohólicas contienen los productos químicos protectores tales como etanol que bloquean la conversión del metanol en el formaldehído, pero las bebidas con aspartame no contienen ningún “factor protector”; (b) el metanol y el formaldehído se han demostrado causar toxicidad crónica en seres humanos; y (c) los niveles bajos del metanol y del formaldehído en metabolismo humano natural están rigurosamente controlados, mientras que los aumentos en los niveles del metanol causados por la ingestión del aspartame se metabolizan diferentemente.

Para la comparación, se debe observar que el contenido del metanol (en miligramos/litro) de una ligth que contiene el aspartame es 55, mientras que el contenido del metanol es 20-36 para los vinos blancos, 99-271 para los vinos tintos, 181-2425 para el brandy, 16-680 para el jugo de uva y 180-218 para el jugo del tomate.

Imagen:Methanol3.jpg

En 1998, un equipo de científicos en España condujo un experimento en roedores para medir indirectamente los niveles de las aducciones del formaldehído en los órganos después de la ingestión del aspartame. Hicieron esto radiolabeling la porción del metanol de aspartame. Los científicos concluyeron que el límite del formaldehído a la proteína y al DNA acumuló en el cerebro, el hígado, riñones y otros tejidos finos después de la ingestión de 20 mg/kg o de 200 mg/kg de aspartame. Sin embargo, los representantes del fabricante del aspartame los niveles han discutido que estos científicos no medían directamente el formaldehído, pero simplemente el medir de algún subproducto del metanol del aspartame. Tephly piensa que el subproducto no era formaldehído. Los investigadores han indicado que los datos en el experimento lo han probado que era el formaldehído.

[editar] Phenilalanina

Uno de los grupos funcionales en aspartame es el phenilalanina, que es inseguro para ésos llevados con phenylketonuria. El Phenylalanine es un aminoácido encontrado comúnmente en alimentos. El aproximadamente 50% de aspartame (por la masa) se analiza en el phenylalanine. Porque el aspartame se metaboliza y se absorbe muy rápidamente (desemejante de las proteínas phenylalanine-que contienen en alimentos), se sabe que podría el aspartame los niveles del plasma de sangre del punto del phenylalanine. el discusión se centra encendido si un punto significativo en phenylalanine del plasma de sangre ocurre en los niveles típicos de la ingestión del aspartame, si una afluencia repentina del phenylalanine en la circulación sanguínea afecta al contrario el uptake de otros aminoácidos en el cerebro y la producción de neurotransmisores (puesto que el phenylalanine compite con otros aminoácidos neutrales grandes (LNAAs) para la entrada en el cerebro en la barrera del cerebro de la sangre), y si una subida significativa de niveles del phenylalanine sería concentrada en el cerebro de fetos y ser potencialmente neurotoxic. Observar que muchos de los surtidores alimenticios de los suplementos que denunci el aspartame como tóxico también venden el phenylalanine como suplemento alimenticio. [citación necesitada]

De acuerdo con antecedentes de usuarios del aspartame, de niveles que miden de neurotransmisores en los cerebros de animales y de medir el potencial del aspartame de causar asimientos en animales, algunos científicos piensan que el aspartame pueda afectar la producción del neurotransmisor. piensan que incluso un punto moderado en niveles del phenylalanine del plasma de sangre de la ingestión típica puede tener consecuencias adversas en uso a largo plazo. Se refieren especialmente que el phenylalanine se puede concentrar en cerebros fetales a un nivel potencialmente neurotoxic. otros científicos piensan que una subida del phenylalanine del plasma de sangre es insignificante en el uso típico del aspartame y sus estudios no demuestran ningún efecto significativo sobre niveles del neurotransmisor en el cerebro o cambios en umbrales del asimiento. Además, dicen que los efectos nocivos probados del phenylalanine en fetos se han considerado solamente cuando los niveles del phenylalanine de la sangre permanecen en los altos niveles en comparación con de vez en cuando ser claveteados a los altos niveles.

Un dulcificante alternativo, Neotame, se ha desarrollado al parecer para solucionar el problema del phenylalanine asociado a Aspartame (véase Neotame).

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[editar] Aspartic acid

Aspartic acid is an amino acid commonly found in foods. Approximately 40% of aspartame (by mass) is broken down into aspartic acid. Because aspartame is metabolized and absorbed very quickly (unlike aspartic acid-containing proteins in foods), it is known that aspartame could spike blood plasma levels of aspartate.^[1][2] Aspartic acid is in a class of chemicals that in high concentrations can act as an excitotoxin, inflicting damage on brain and nerve cells. High levels of excitotoxins have been shown in hundreds of animal studies to cause damage to areas of the brain unprotected by the blood-brain barrier and a variety of chronic diseases arising out of this neurotoxicity.^[3][4] The debate amongst scientists has been raging since the early 1970s, when Dr. John Olney found that high levels of aspartic acid caused damage to the brains of infant mice.^[5] Dr. Olney and consumer attorney, James Turner filed a protest with the FDA to block the approval of aspartame. The debate is complex and has focused on several areas: (a) whether the increase in plasma aspartate levels from typical ingestion levels of aspartame is enough to cause neurotoxicity in one dose or over time, (b) whether humans are susceptible to the neurotoxicity from aspartic acid seen in some animal experiments, (c) whether aspartic acid increases the toxicity of formaldehyde, (d) whether neurotoxicity from excitotoxins should consider the combined effect of aspartic acid and other excitotoxins such as glutamic acid from monosodium glutamate. The neuroscientists at a 1990 meeting of the Society for Neuroscience had a split of opinion on the issues related to neurotoxic effects from excitotoxic amino acids found in some additives such as aspartame.^[6]

Some scientists think that humans and other primates are not as susceptible to excitotoxins as rodents and therefore there is little concern with aspartic acid from aspartame.^[7][8] While they agree that the combined effects of all food-based excitotoxins should be considered^[9], their measurements of the blood plasma levels of aspartic acid after ingestion of aspartame and monosodium glutamate demonstrate that there is not a cause for concern.^[10][11] Other scientists think that primates are susceptible to excitotoxic damage^[12] and that humans concentrate excitotoxins in the blood more than other animals.^[13] Based on these findings, they think that humans are approximately 5-6 times more susceptible to the effects of excitotoxins than are rodents.^[14] While they agree that typical use of aspartame does not spike aspartic acid to extremely high levels in adults, they are particularly concerned with potential effects in infants and young children,^[15] the potential long-term neurodegenerative effects of small-to-moderate spikes on plasma excitotoxin levels,^[16] and the potential dangers of combining formaldehyde exposure from aspartame with excitotoxins given that chronic methanol exposure increases excitoxin levels in susceptible areas of the brain ^[17][18] and that excitotoxins may potentiate formaldehyde damage.^[19]

[editar] Aspartylphenylalanine diketopiperazine

This type of diketopiperazine (DKP) is created in products as aspartame breaks down over time. For example, researchers found that 6 months after aspartame was put into carbonated beverages, 25% of the aspartame had been converted to DKP.^[20] Concern amongst some scientists has been expressed that this form of DKP would undergo a nitrosation process in the stomach producing a type of chemical that could cause brain tumors.^[21][22] Other scientists think that the nitrosation of aspartame or the DKP in the stomach would not produce a chemical that would cause brain tumors. In addition, only a minuscule amount of the nitrosated chemical would be produced.^[23] There are very few human studies on the effects of this form of DKP. However, a (one-day) exposure study showed that the DKP was tolerated without adverse effects.^[24]

[editar] Responses

A number of different policy statements and responses have been issued during the controversy.

• The Food and Drug Administration says that more than "100 toxicological and clinical studies it has reviewed confirm that aspartame is safe for the general population."^[25]
• The American Cancer Society argues that "since aspartame is broken down into these components before it is absorbed into the blood stream, aspartame in its initial form does not have the opportunity to travel to target organs, including the brain, to cause cancer."^[26]
• The American Heart Association concludes that "extensive investigation so far hasn’t shown any serious side effects from aspartame."^[27]
• The National Cancer Institute argues "there is no evidence that the regulated artificial sweeteners on the market in the United States are related to cancer risk in humans."^[28]
• The Centers for Disease Control and Prevention says "The number of instances of persons challenging themselves several times with aspartame-containing products and reporting symptoms with each rechallenge suggests that some individuals may be sensitive. The only way to clearly determine this is through focused clinical studies." on its report that analyzed official complaints of aspartame.^[29]
• A double-blind study published in Biological Psychiatry tested aspartame on people with a history of depression. The results show that 100% of people taking aspartame experienced nausea and 63% suffered from nervousness.^[30]
• A double-blind study published in American Academy of Neurology concludes "Aspartame appears to exacerbate the amount of EEG spike wave in children with absence seizures. Further studies are needed to establish if this effect occurs at lower doses and in other seizure types."^[31]
• A study published in Environmental Health Perspectives says "Aspartame also potentiates the induction of seizures by inhaled fluorothyl or by electroconvulsive shock. Perhaps regulations concerning the sale of food additives should be modified to require the reporting of adverse reactions and the continuing conduct of mandated safety research."^[32]

• The Association for Consumers Action on Safety and Health issued a consumer alert related to the dangers of ingesting aspartame.^[33]
• The National Health Federation calls aspartame a "neurotoxic artificial sweetener."^[34]
• The Feingold Association has stated that aspartame "is reported to cause a variety of neurological effects from headache to seizures and brain tumors."^[35]
• The UK Campaign for Truth in Medicine (consumer organization) says that "Aspartame is, by far, the most dangerous substance on the market that is added to foods."^[36]
• Several papers have been published in late 2006 and early 2007 that insisted that conclusive proof linking aspartame to multiple diseases, such as brain cancer, Parkinson Disease, and Gulf War Syndrome (GWS), had been found.Plantilla:Fact

[editar] Recently-published research

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.^[21] The results of a large seven-year study into the long-term effects of eating aspartame in rats by the European Ramazzini Foundation for cancer research in Bologna, Italy were released in July 2005. The study of 1,800 rats demonstrates that aspartame administered at varying levels in feed causes a statistically significant increase of lymphomas-leukemias and malignant tumors of the kidneys in female rats and malignant tumors of peripheral nerves in male rats. The study showed that there was no statistically significant link between aspartame and brain tumors.

The study,^[37] published in Environmental Health Perspectives, raised concerns about the levels of aspartame exposure. However, the European Food Safety Authority's (EFSA) review found that the European Ramazzini Foundation's conclusion that aspartame is a carcinogen was flawed and not supported by the data.^[38] The American Food & Drug Administration's (FDA) review of the Razzamini study is still pending.^[39]

A review of the Ramazzini study by the European Food Safety Authority (EFSA), published 5 May 2006, concluded that the increased incidence of lymphomas/leukaemias reported in treated rats was unrelated to aspartame, the kidney tumors found at high doses of aspartame were not relevant to humans, and that based on all available scientific evidence to date, there is no reason to revise the previously established Acceptable Daily Intake levels for aspartame.^[40] The European Ramazzini Foundation responded to the EFSA findings by stating that they thought the 16% increase in incidence of lymphoma and leukemia between the aspartame group and control group signified that these cancers were caused by aspartame ingestion.^[41] As the EFSA had already addressed this in their 5 May 2006 press release, no further press release was made.^[42] An open letter to the European Union Food Safety Authority, posted on the website of the World Natural Health Organization on 29 December 2006 states that the EFSA's published conclusion regarding the Ramazzini study's raw data "is bizarre", and also draws attention to conflicts of interest regarding members of the EFSA's panel:

The Guardian on 15 May 2006^[43] quoted EFSA Executive Director, Dr Herman Koeter: "Dr Koeter said, he wanted to clear up misunderstandings about "conflicts of interest" among his advisory panel overseeing the review. MEPs complained last month that the scientist who chairs the advisory panel, Dr Susan Barlow, works for the International Life Sciences Institute, a body funded by sweetener manufacturers and major aspartame users such as Coca Cola, PepsiCo and Nestle, and Monsanto.^[44] The European commission was also told by MEPs of other "conflicts of interest". One scientist involved in the review had declared a research grant from Ajinomoto, the leading Japanese manufacturer of aspartame, they said. Other panel members listed links with food processors such as Nestlé in their declarations of interest. But to say that these scientists therefore have a conflict of interest was a misunderstanding, Dr Koéter explained to the Rome conference. "The expertise required (to judge any new study on whether aspartame causes cancer) almost inevitably means having a previous involvement." Eliminate the scientists who had worked in the area before or who had worked for industry and there would be no scientists left, he said. The panel had been "fully impartial". He insults our intelligence. Are we to believe there are no scientists in Europe capable of conducting this study except those paid by the aspartame industry? The one thing Dr Koeter didn't get from the advisory panel was impartiality.

A study published in April 2006 sponsored by the National Cancer Institute involved 340,045 men and 226,945 women, ages 50 to 69, found no statistically significant link between aspartame consumption and leukemias, lymphomas or brain tumors.^[45] The study used surveys filled out in 1995 and 1996 detailing food and beverage consumption. The researchers calculated how much aspartame they consumed, especially from sodas or from adding the sweetener to coffee or tea. The researchers report, "Our findings from this epidemiologic study suggest that consumption of aspartame-containing beverages does not raise the risk of hematopoietic or brain malignancies."

Critics of this study point out that while the study looked at humans, it did not look at life-long aspartame consumption as did the Ramazzini study. The Ramazzini study simulated life-long consumption from childhood through old age (simulating 60 to 90 years of use). However the new National Cancer Institute study simply looked at subjects who consumed diet drinks during a twelve-month period from 1995 to 1996, without determining aspartame intake prior to the start of the study. Neurosurgeon Dr Russell Blaylock, commenting on the NCI study, remarked that "The greatest risk of leukemia and lymphoma would be in a younger population (young children and adolescents) and they would need to be exposed regularly from early in life."^[46] Given that aspartame has only been publicly available for about a quarter of a century (in France from 1979, the USA since 1982, and the UK since 1983),^[47] not one of the people examined in the NCI study could have ingested any aspartame product during their formative growth years, until they were at least into their mid-twenties.

The Ramazzini study had the disadvantage of being an animal study but looked at life-long consumption of aspartame. The National Cancer Institute study was a human study, but only looked at a limited range of older subjects with relatively short-term consumption of diet drinks. Finally, the questionnaire did not ask users to estimate aspartame consumption, only diet drink consumption.^[48]

[editar] See also

• Canderel
• Equal (sweetener)
• Excitotoxicity
• G. D. Searle & Company
• NutraSweet
• Sugar substitute

[editar] Enlaces externos

[editar] Films

• Sweet Misery: A Poisoned World,
  Google video *[2]. Directed by Cori Brackett and J. T. Waldron, 2004.
• David Icke on Aspartame
• Sweet Misery Trailer

[editar] Websites: Pro-aspartame

• Aspartame Information Service
• Aspartame Archives
• Aspartame—American Council on Science and Health
• Sugar Substitutes (U.S. FDA web page)
• U.S. FDA web page "FDA Consumer" magazine article, "Artificial Sweeteners: No Calories...Sweet!"
• Update on Aspartame Safety; EC Scientific Committee on Food (263 KB PDF)
• Health Canada
• GreenFacts.org: Review of the EC Scientific Committee’s 2002 Update
• American Heart Association
• National Cancer Institute
• Multiple Scelrosis Foundation
• Site of the Calorie Control Council, which is, according to its website, a "non-profit association representing the low-calorie and reduced-fat food and beverage industry."

[editar] Websites: Anti-aspartame

• Aspartame Support Group
• Aspartame Toxicity Information Center
• Aspartame—Dorway to Discovery
• How Excitotoxins Were Discovered
• Excitotoxins—MSG and Aspartame
• Aspartame—Mission Possible News/Articles
• Aspartame Consumer Safety Network
• Aspartame - The Secret Danger
• Aspartame—Former U.S. FDA Investigator
• Sweet Poison
• Update on Aspartame Safety; Response to EC Scientific Committee on Food
• Responses to Aspartame and Its Effects on Health
• Nutrapoison, Part One by Alex Constantine
• Dangers of Aspartame Links Page
• Reported Aspartame Toxicity Effects, a well-referenced article on reported reactions to aspartame.

[editar] News & General Articles

• Deconstructing Dinner on Aspartame, featuring the European Ramazzini Foundation study, Kootenay Co-op Radio CJLY, Canada, October 12, 2006
• Safety of Artificial Sweetener Called Into Question by MP, The Guardian, UK, December 15, 2005
• The Straight Dope on aspartame
• Free E-course on Aspartame Dangers
• The Lowdown on Sweet?—article in New York Times
• The Safety of Aspartame, The New York Times, USA, February 21, 2006
• Artificial Sweetener Given the All Clear, New Scientist, May 13, 2006
• Center for Disease Control Full Report on Aspartame Complaints
• "Kiss My Aspartame"—the Urban Legends Reference Pages
• The Aspartame Epidemic

[editar] Books

^{(most recently published listed first)}

• Dr Joseph Mercola and Dr Kendra Pearsall, Sweet Deception: Why Splenda, NutraSweet, and the FDA May Be Hazardous to Your Health, (Nelson Books, November 2006). ISBN 0-78522-179-4 and ISBN-13 978-0785221791.
• Dr H.J. Roberts, Aspartame Disease: An Ignored Epidemic, (Sunshine Sentinel Press, May 2001). ISBN 1-88424-317-7 and ISBN-13 978-1884243172.
• Janet Starr Hull, Sweet Poison: How the World's Most Popular Artificial Sweetener Is Killing Us - My Story, (New Horizon Press, September 1998). ISBN 0-88282-202-0 and ISBN-13 978-0882822020.
• Miladie L. Dillard, Food Sweeteners - Aspartame and Its Adverse Reactions, Strange Symptoms, Illness Behavior and Controversy: Index of New Information With Authors and Subjects, (Abbe Pub Assn of Washington DC, Reprint edition, March 1997). ISBN 1-55914-850-0 and ISBN-13 978-1559148504.
• Dr Russell L. Blaylock, Excitotoxins: The Taste That Kills, (Health Press, December 1996). ISBN 0-92917-325-2 and ISBN-13 978-0929173252.
• Christian Tschanz (Editor), Harriett H. Butchko (Editor), W. Wayne Stargel (Editor), Frank N. Kotsonis (Editor), The Clinical Evaluation of a Food Additive: Assessment of Aspartame, (CRC, June 1996). ISBN 0-84934-973-7 and ISBN-13 978-0849349737.
• Dr H.J. Roberts, Sweet'Ner Dearest: Bittersweet Vignettes About Aspartame (Nutrasweet), (Sunshine Sentinel Press, October 1992). ISBN 0-96332-601-5 and ISBN-13 978-0963326010.
• Dr H.J. Roberts, Aspartame (Nutrasweet): Is It Safe?, (Charles Press Pubs, September 1992). ISBN 0-91478-358-0 and ISBN-13 978-0914783589.
• Jacqueline Van de Kamp, Adverse effects of aspartame: January 1986 through December 1990: 167 citations (Current bibliographies in medicine) (1991). ISBN 0-16014-229-6 and ISBN-13 978-0160142291.

[editar] References