Aspartame – is it safe?

By Amanda Johnson 16/06/2010 11


The safety questions around aspartame were back on the agenda yet again today, with a Coca Cola funded webinar presentation by Dr Bernadene Magnuson.

Dr Magnuson, a Senior Scientific and Regulatory Consultant at Cantox Health Sciences International and University of Toronto Associate Adjunct Professor of Nutritional Sciences, gave an excellent review of the latest research on the safety of aspartame — very similar to the presentation she gave in Wellington 18 months ago, which I attended.

I think most of us are fairly well aware by now that aspartame is safe, given the comprehensive reviews of this sweetener that have taken place by many of the food safety agencies around the world. Not to mention the fact that there is no plausible mechanism by which it could be deemed to be harmful. Aspartame is simply two amino acids (aspartic acid and phenylalanine) bonded together with a methyl group. Upon entering the body the methyl group is cleaved off to form methanol (which is easily broken down by the liver — the body being well equipped to deal with methanol, which is found in many foods including fruits and vegetables) and the two amino acids are absorbed and utilized as any other proteins would be by the body.

Dr Magnuson, during her presentation, reviewed numerous animal studies as well as human epidemiological studies and clinical trials. There is no good evidence to show aspartame is carcinogenic, or has any adverse effects on the central nervous system, as has been claimed by some of those campaigning against this sweetener (take a look at the Sweet Poison website for a list of all the ailments that aspartame is supposed to cause, from blindness to irreversible brain damage and suicidal tendencies)!!

One has to conclude that overall, the metabolism of aspartame is well understood, the safety is well researched, and has been established in numerous studies, and there is no good quality evidence for any adverse effects.

Aspartame is used worldwide in over 90 countries and is an ingredient in over 6000 products. More information about the safety of aspartame can be found in the paper published in Critical Reviews in Toxicology in 2007, Aspartame: A Safety Evaluation Based on Current Use Levels, Regulations, and Toxicological and Epidemiological Studies. Dr. Magnuson was the lead author for this expert panel review of aspartame safety.

More general information about aspartame can be found in the Science Media Centre fact sheet on this topic.


11 Responses to “Aspartame – is it safe?”

  • “the fact that there is no plausible mechanism by which it could be deemed to be harmful”
    Well, there is a mechanism, but only if you happen to be phenylketonuric. For the rest of us, it is quite safe.
    You’ll never convince the True Believers, though.

  • Yes, I agree – those with PKU should certainly avoid aspartame! There’s more about this in the SMC fact sheet on aspartame, which you’ll find a link to above.

  • I don’t nearly know enough relevant science to comment intelligently here (although some would say that hasn’t stopped me in the past!), but permit me the indulgence of a few questions and observations:

    – I have to wonder why Coca-Cola funded the webinar. I mean, what’s the point? It just lays them open to accusations of bias and calls what might be perfectly good science into question. Never trust someone to tell you the truth if their income depends on them lying to you, and all that.
    – I take the point about having no explanation for aspartame harm, yet there does seem to be a body of complaint about it, which must surely be explained by something. For example: If I use artificial sweeteners in coffee, I get an instant nasty headache, every time I have tried. Not so in tea, as it happens, but I don’t use sugar or sweeteners in either anymore. As there is “no plausible mechanism by which it could be deemed to be harmful”, is this delusion on my part? Or merely something we don’t understand?
    – I’m generally concerned about the “no plausible mechanism” defense, when I come across it. It’s an easy thing to say, but the logic seems poor. After all, we have got it wrong before, with consequences for human suffering. It would be nice to find a middle way that facilitates the progressive improvement aspect of science, so allowing some mistakes, but without undue harm to people. Perhaps an added dose of humility, patience and caution is required, or perhaps just less commercial pressure.
    – The “only” in “only if you happen to be phenylketonuric” is surely a big call, rosalind? Perhaps you mean it’s the only one we currently know about?

    Personally I avoid aspartame, but mostly just because I don’t need it. It tends to be in foods that I don’t eat/drink, and it’s neither food nor medication. (Why does it even exist?) We may not see a pathway to harm, but certainly the only pathway to benefit I see is for the manufacturers and sellers of aspartame.

  • fructose, aspartame, caramel in soft drinks and nonalcoholic fatty liver disease, W Nseir, F Nassar, N Assy, World J Gastroenterol: Rich Murray 2010.06.07
    http://rmforall.blogspot.com/2010_06_01_archive.htm
    Monday, June 7, 2010
    [ at end of each long page, click on Older Posts ]
    http://groups.yahoo.com/group/aspartameNM/message/1602
    [ You may have to Copy and Paste URLs into your browser ]

    “During regular soft drinks consumption, fat accumulates in the
    liver by the primary effect of fructose which increases
    lipogenesis, and in the case of diet soft drinks, by the
    additional contribution of aspartame sweetener and
    caramel colorant which are rich in advanced glycation end
    products that potentially increase insulin resistance and
    inflammation.” 2010.06.07

    “From our study, it seems that fructose is not the only risk
    factor of liver disease, because 40% of our cohort were
    drinking Diet Coke sweetened with aspartame.

    Aspartame is absorbed from the intestine and metabolized
    by the liver to form phenylalanine, aspartic acid and methanol.
    This process causes mitochondrial dysfunction and ATP
    depletion, which contribute to accumulation of fat (29).

    Also, regarding obesity and aspartame, formaldehyde
    converted from the free methyl alcohol accumulates in the
    cells and damages mitochondrial DNA, with most toxicity
    effects occurring in the liver.

    Finally, the effect of caramel colourant has been incriminated
    as a cause of elevated liver enzymes and may be a potential
    source of advanced glycation end product, which may
    promote insulin resistance and can be proinflammatory
    (5,6,20).” 2008 October

    “29. Trocho C, Pardo R, Rafecas I, et al.
    Formaldehyde derived from dietary aspartame binds to tissue
    components in vivo.
    Life Sci. 1998; 63: 337-49. [PubMed]”

    [ See also:

    Woodrow C Monte, PhD, Emiritus Prof. Nutrition gives
    many PDFs of reseach — methanol (11% of aspartame) puts
    formaldehyde into brain and body — multiple sclerosis,
    Alzheimer’s, cancers, birth defects, headaches:
    Rich Murray 2010.05.13
    http://rmforall.blogspot.com/2010_05_01_archive.htm
    Thursday, May 13, 2010
    http://groups.yahoo.com/group/aspartameNM/message/1601

    ( Other formaldehyde sources include alcohol drinks and
    tobacco and wood smoke.
    Adequate folic acid levels protect most people from some
    harm, but not for the brain and retinas.) ]

    World J Gastroenterol. 2010 Jun 7; 16(21): 2579-88.
    Soft drinks consumption and nonalcoholic fatty liver disease.
    Nseir W, w.nseir@yahoo.com;
    Nassar F,
    Assy N. assy.n@ziv.health.gov.il;

    Abstract

    Nonalcoholic fatty liver disease (NAFLD) is a common
    clinical condition which is associated with metabolic syndrome
    in 70% of cases.

    Inappropriate dietary fat intake, excessive intake of soft
    drinks, insulin resistance and increased oxidative stress
    combine to increase free fatty acid delivery to the liver, and
    increased hepatic triglyceride accumulation contributes to
    fatty liver.

    Regular soft drinks have high fructose corn syrup which
    contains basic sugar building blocks, fructose 55% and
    glucose 45%.

    Soft drinks are the leading source of added sugar worldwide,
    and have been linked to obesity, diabetes, and metabolic
    syndrome.

    The consumption of soft drinks can increase the prevalence of
    NAFLD independently of metabolic syndrome.

    During regular soft drinks consumption, fat accumulates in the
    liver by the primary effect of fructose which increases
    lipogenesis, and in the case of diet soft drinks, by the
    additional contribution of aspartame sweetener and caramel
    colorant which are rich in advanced glycation end products
    that potentially increase insulin resistance and inflammation.

    This review emphasizes some hard facts about soft drinks,
    reviews fructose metabolism, and explains how fructose
    contributes to the development of obesity, diabetes,
    metabolic syndrome, and NAFLD. PMID: 2051807

    J Hepatol. 2009 Nov; 51(5): 918-24. Epub 2009 Aug 21.
    Soft drink consumption is associated with fatty liver disease
    independent of metabolic syndrome.
    Abid A,
    Taha O,
    Nseir W,
    Farah R,
    Grosovski M,
    Assy N.
    Liver Unit, Ziv Medical Center, Safed, Israel.
    Comment in:
    J Hepatol. 2010 Jun;52(6):954; author reply 954.

    Abstract

    BACKGROUND/AIMS:
    The independent role of soft drink consumption in
    non-alcoholic fatty liver disease (NAFLD) patients remains
    unclear.
    We aimed to assess the association between consumption of
    soft drinks and fatty liver in patients with or without metabolic
    syndrome.
    METHODS:
    We recruited 31 patients (age: 43+/-12 years) with NAFLD
    and risk factors for metabolic syndrome,
    29 patients with NAFLD and without risk factors for
    metabolic syndrome, and
    30 gender- and age-matched individuals without NAFLD.
    The degree of fatty infiltration was measured by ultrasound.
    Data on physical activity and intake of food and soft drinks
    were collected during two 7-day periods over 6 months
    using a food questionnaire.
    Insulin resistance, inflammation, and oxidant-antioxidant
    markers were measured.
    RESULTS:
    We found that 80% of patients with NAFLD had excessive
    intake of soft drink beverages (>500 cm(3)/day) compared to
    17% of healthy controls (p<0.001).
    The NAFLD group consumed five times more carbohydrates
    from soft drinks compared to healthy controls
    (40% vs. 8%, p<0.001).
    Seven percent of patients consumed one soft drink per day,
    55% consumed two or three soft drinks per day, and
    38% consumed more than four soft drinks per day for most
    days and for the 6-month period.

    The most common soft drinks were Coca-Cola
    (regular: 32%; diet: 21%)
    followed by fruit juices (47%).

    Patients with NAFLD with metabolic syndrome had similar
    malonyldialdehyde, paraoxonase, and C-reactive protein
    (CRP) levels but higher homeostasis model assessment
    (HOMA) and higher ferritin than NAFLD patients without
    metabolic syndrome
    (HOMA: 8.3+/-8 vs. 3.7+/-3.7 mg/dL, p<0.001;
    ferritin: 186+/-192 vs. 87+/-84 mg/dL, p<0.01).
    Logistic regression analysis showed that soft drink
    consumption is a strong predictor of fatty liver
    (odds ratio: 2.0; p<0.04) independent of metabolic syndrome
    and CRP level.
    CONCLUSIONS:
    NAFLD patients display higher soft drink consumption
    independent of metabolic syndrome diagnosis.
    These findings might optimize NAFLD risk stratification.
    PMID: 19765850

    http://www.ncbi.nlm.nih.gov/pubmed/18925303

    Can J Gastroenterol. 2008 Oct; 22(10): 811-6.
    Soft drink consumption linked with fatty liver in the absence
    of traditiona risk factors.
    Assy N, Nasser G, Kamayse I, Nseir W, Beniashvili Z,
    Djibre A, Grosovski M.
    Liver Unit, Ziv Medical Center, Safed, Israel.
    assy.n@ziv.health.gov.il
    [ more …..]

  • four Murray AspartameNM reviews in SE Jacob & SA
    Stechschulte debate with EG Abegaz & RG Bursey of
    Ajinomoto re migraines from formaldehyde from aspartame,
    Dermatitis 2009 May: TE Hugli — folic acid with V-C
    protects: Rich Murray 2009.08.12
    http://rmforall.blogspot.com/2009_08_01_archive.htm
    Wednesday, August 12, 2009
    http://groups.yahoo.com/group/aspartameNM/message/1582
    [ extracts ]

    Formaldehyde, aspartame, migraines: a possible connection.
    Abegaz EG, Bursey RG.
    Dermatitis. 2009 May-Jun;20(3):176-7; author reply 177-9.
    No abstract available. PMID: 19470307

    Eyassu G. Abegaz *
    Robert G. Bursey
    Ajinomoto Corporate Services LLC, Scientific & Regulatory
    Affairs, 1120 Connecticut Ave., N.W., Suite 1010,
    Washington, DC 20036
    * Corresponding author. Tel.: +1 202 457 0284;
    fax: +1 202 457 0107.
    abegazee@ajiusa.com; (E.G. Abegaz),
    burseyb@ajiusa.com; (R.G. Bursey)

    “For example, fruit juices, coffee, and alcoholic beverages
    produce significantly greater quantities of formaldehyde than
    aspartame-containing products. [6]”

    “[6] Magnuson BA, Burdock GA, Doull J, et al. Aspartame:
    a safety evaluation based on current use levels, regulations,
    and toxicological and epidemiological studies.
    Crit Rev Toxicol 2007;37:629-727”

    [ two detailed critiques of industry affiliations and biased
    science in 99 page review with 415 references by BA
    Magnuson, GA Burdock and 8 more, Critical Reviews in
    Toxicology, 2007 Sept.: Mark D Gold 13 page:
    also Rich Murray 2007.09.15: 2008.03.24
    http://rmforall.blogspot.com/2008_03_01_archive.htm
    Monday, March 24, 2008
    http://groups.yahoo.com/group/aspartameNM/message/1531

    “Nearly every section of the Magnuson (2007) review has
    research that is misrepresented
    and/or crucial pieces of information are left out.

    In addition to the misrepresentation of the research,
    readers (including medical professionals) are often not told
    that this review was funded by the aspartame manufacturer,
    Ajinomoto, and the reviewers had enormous conflicts of
    interest.” ]
    [ More…..]

  • Is there a reason why my comment is still in moderation 4 days after posting? It’s not very conducive to dialogue to have very large delays between messages…

    I would have thought it wasn’t that controversial!

  • Some interesting comments here on aspartame safety. Personally, I am happy with the evidence that shows aspartame is safe, and I happily consume diet drinks myself. Having said that, for those who wish to avoid aspartame, any products containing this sweetener will be labelled as such (either by name or number – 951), and can easily be avoided.

  • I am pleased that my comments, based on recent mainstream medical journal evidence, are being allowed here, since this supports discussion based on publicly shared evidence and reason, seeking truth for the common good.

    Vestibulocochlear toxicity in a pair of siblings [doctor & nurse] 15 years
    apart secondary to aspartame: two case reports, Paul Pisarik & Dasha Kai,
    Cases J 2009.09.15 free full text: Rich Murray 2010.05.04
    http://rmforall.blogspot.com/2010_05_01_archive.htm
    Tuesday, May 4, 2010
    [ at end of each long page, click on Older Posts ]
    http://groups.yahoo.com/group/aspartameNM/message/1600
    [ You may have to Copy and Paste URLs into your browser ]

    recent aspartame (methanol, formaldehyde, formic acid) symptoms in English professor: Kristi Siegel: Rich Murray 2010.04.17
    http://rmforall.blogspot.com/2010_04_01_archive.htm
    Saturday, April 17, 2010
    [ at end of each long page, click on Older Posts ]
    http://groups.yahoo.com/group/aspartameNM/message/1599
    [ You may have to Copy and Paste URLs into your browser ]

    formaldehyde from 11% methanol part of aspartame causes severe allergic dermatitis in boy, JE Jacob et al, Pediatric Dermatology 2009 Nov: Rich Murray 2010.03.30
    http://rmforall.blogspot.com/2010_03_01_archive.htm
    Tuesday, March 30, 2010
    [ at end of each long page, click on Older Posts ]
    http://groups.yahoo.com/group/aspartameNM/message/1597
    [ You may have to Copy and Paste URLs into your browser ]

    kid asthma related to formaldehyde, G McGwin Jr, J Lienert, JI Kennedy Jr, Environmental Health Perspectives 2009.11.06 abstract: Rich Murray 2009.12.01
    http://rmforall.blogspot.com/2009_12_01_archive.htm
    Tuesday, December 1, 2009
    [ at end of each long page, click on Older Posts ]
    http://groups.yahoo.com/group/aspartameNM/message/1590
    [ You may have to Copy and Paste URLs into your browser ]

    recent aspartame (methanol, formaldehyde, formic acid) symptoms in English professor: Kristi Siegel: Rich Murray 2010.04.17
    http://rmforall.blogspot.com/2010_04_01_archive.htm
    Saturday, April 17, 2010
    http://groups.yahoo.com/group/aspartameNM/message/1599

  • older women drinking over 2 aspartame beverages daily had 30% decline kidney function in 11 years, Nurses Health Study, Julie Lin, Gary C Curhan, Brigham and Women’s Hospital, Boston: Rich Murray 2009.11.02
    http://rmforall.blogspot.com/2009_11_01_archive.htm
    Monday, November 2, 2009
    [ at end of each long page, click on Older Posts ]
    http://groups.yahoo.com/group/aspartameNM/message/1588
    [ You may have to Copy and Paste URLs into your browser ]

    consider co-factors (methanol, formaldehyde, and protective folic acid), re UK FSA test of aspartame in candy bars on 50 reactors, Stephen L Atkin, Hull York Medical School: Rich Murray 2009.09.29
    http://rmforall.blogspot.com/2009_09_01_archive.htm
    Tuesday, September 29, 2009
    [ at end of each long page, click on Older Posts ]
    http://groups.yahoo.com/group/aspartameNM/message/1587
    [ You may have to Copy and Paste URLs into your browser ]

  • rmforall, I’m not quite sure what your point is posting all of these links some of which do not work. The first one that I managed to open appears to be a case study written by a Professor of English?
    It would be much more interesting if you produced an argument either for or against aspartame use based on these references.

    Personally I tend to avoid anything that uses artificial sweeteners as I find the taste/aftertaste unpleasant.