The Truth about Aspartame

The artificial sweetener aspartame is falsely accused of being the cause of nearly every disease.

by Brian Dunning

Filed under Conspiracies, Urban Legends

Skeptoid #127
November 11, 2008
Podcast transcript | Listen | Subscribe
Also available in Chinese | Russian

As a kid I remember hearing that the artificial sweetener aspartame would neutralize your digestive enzymes, and anything else you ate that day would turn to fat. Although this makes no sense biochemically at any level, it sounded scientific enough to me and I was satisfied with it — at least enough to justify my dislike for its awful flavor. It turns out that my fat-producing claim was about the mildest of many arguments made by a growing anti-aspartame movement, and biochemically-nonsensical as it was, it was among the sanest of the arguments. Take a look at websites such as,, and, and you'll see that a whole new breed of aspartame opponents has taken activism to a whole new level. Here are a few quotes from those web sites:

Thank you Montel Williams for having the fortitude to say: "Multiple Sclerosis is often misdiagnosed, and that it could be aspartame poisoning"

NutraSweet® killed my mother and has killed and/or wounded millions of innocent people in the US and abroad.

Aspartame converts to formaldehyde in vivo in the bodies of laboratory rats.


Did O J Simpson Have a Reaction to Aspartame that led to the deaths of Nicole Simpson and Ron Goldman?


After more than twenty years of aspartame use, the number of its victims is rapidly piling up, and people are figuring out for themselves that aspartame is at the root of their health problems. Patients are teaching their doctors about this nutritional peril, and they are healing themselves with little to no support from traditional medicine.

Donald Rumsfeld disregarded safety issues and used his political muscle to get Aspartame approved.

The Nazi Scientist's Poison Projects: Poison adults with Aspartame

Because of your and/or your forbearers [sic] exposure to toxics like Aspartame, a summation of immune, mitochondrial, DNA, and MtDNA (genetic) damage has occurred in your body that has made your body unable to deal with chemical insults.

The doctor that was in charge of the lab to study Aspartame, reported that the substance was too toxic and he mysteriously dissappeared [sic] and all the paper work somehow was destroyed.

The Nazis actually won the war. They just pretended to lose so that we wouldn't notice them take over our government.

Well, that's enough for now. And if you haven't heard those, you've almost certainly received one of several hoax emails that people have been forwarding around since 1995, according to, giving an equally long list of untrue claims about aspartame being the cause of nearly every illness. One is even falsely attributed to Dr. Dean Edell. Suffice it to say that every possible kind of attack is made against aspartame: Pseudoscientific attacks where they throw out whole dictionaries of scientific sounding nonsense; guilt by association attacks where they mention aspartame alongside Adolf Hitler and Donald Rumsfeld; non-sequiturs like pointing out the evils of the corporate structure of pharmaceutical companies as if that is support for how and why an "aspartame detoxification" program will "heal" you of all disease; and even Bible quotations attacking aspartame. The anti-aspartame lobby appears to include everyone from alternative treatment vendors trying to sell their products, to fully delusional conspiracy theorists. Dr. Russell Blaylock, a retired surgeon turned anti-pharmaceutical author and activist, believes aspartame is part of a massive government mind-control plot:

We're developing a society because of all these different toxins known to affect brain function. We're seeing a society that not only has a lot more people of lower IQ, but a lot fewer people of higher IQ. In other words a dumbing down, a chemical dumbing down, of society. ...That leaves them dependent on government because they can't excel. ...So, you know, you can kind of piece it together as to why they are so insistent on spending so many hundreds of millions of dollars of propaganda money to dumb down society.

Tip Skeptoid $2/mo $5/mo $10/mo One time

Discovered in 1965 at Searle (now Pfizer), aspartame is an artificial sweetener, aspartyl-phenylalanine-1-methyl ester. Chemistry types call it a methyl ester of the dipeptide of the amino acids aspartic acid and phenylalanine. It is 180 times as sweet as sugar, which is why it's such an effective low-calorie sweetener: It's needed in only miniscule amounts. Partly in response to all the anti-aspartame craziness out there, a group of scientists from the NutraSweet company published a 2002 review of dozens of studies and clinical trials performed worldwide in the journal Regulatory Toxicology and Pharmacology, which made the following conclusions:

Over 20 years have elapsed since aspartame was approved by regulatory agencies as a sweetener and flavor enhancer. The safety of aspartame and its metabolic constituents was established through extensive toxicology studies in laboratory animals, using much greater doses than people could possibly consume. ...Several scientific issues continued to be raised after approval, largely as a concern for theoretical toxicity from its metabolic components — the amino acids, aspartate and phenylalanine, and methanol — even though dietary exposure to these components is much greater than from aspartame. Nonetheless, additional research, including evaluations of possible associations between aspartame and headaches, seizures, behavior, cognition, and mood as well as allergic-type reactions and use by potentially sensitive subpopulations, has continued after approval. ...The safety testing of aspartame has gone well beyond that required to evaluate the safety of a food additive. When all the research on aspartame is examined as a whole, it is clear that aspartame is safe, and there are no unresolved questions regarding its safety under conditions of intended use.

And yet the claims persist unabated. Here are a few more, addressed point-by-point:

When you hear claims that are supported only by a fringe minority that's in opposition to the scientific consensus, you have good reason to be skeptical right off the bat, but it doesn't mean it's not worth looking into. Aspartame has been looked into ad nauseum even after its approval, and found safe at every try; so at some point you have to depart from rationality to continue supporting the claims made against it. Enjoy your diet Dr. Pepper, it's not going to hurt you; if it was, I'd have been dead decades ago.

Brian Dunning

© 2008 Skeptoid Media Copyright information

References & Further Reading

Aaronovitch, D. Voodoo History: The Role of the Conspiracy Theory in Modern History. New York: Riverhead, 2010.

Butchko, H., Stargel, W., Comer, C., Mayhew, D., Benninger, C., Blackburn, G., de Sonneville, L., Geha, R., Hertelendy, Z., Koestner, A., Leon, A., Liepa, G., McMartin, K., Mendenhall, C., Munro, I., Novotny, E., Renwick, A., Schiffman, S., Schomer, D. "Aspartame: review of safety." Regulatory Toxicology and Pharmacology. 1 Apr. 2002, Volume 35, Number 2 Pt 2: S1-93.

Health Canada. "Aspartame." Food & Nutrition. Health Canada, 14 Oct. 2005. Web. 7 Oct. 2013. <>

Magnuson, B.A., Burdock, G.A., Doull, J., Kroes, R.M., Marsh, G.M., Pariza, M.W., Spencer, P.S., Waddell, W.J.,, R., Williams, G.M. "Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies." Critical Reviews in Toxicology. 1 Jan. 2007, Volume 37, Number 8: 629-727.

Novella, S. "Aspartame – Truth vs Fiction." Science-Based Medicine. Science-Based Medicine, 15 Sep. 2010. Web. 20 Feb. 2012. <>

Rulis, A.M., Levitt, J.A. "FDA's food ingredient approval process: Safety assurance based on scientific assessment." Regulatory Toxicology and Pharmacology. 1 Feb. 2009, Volume 53, Number 1: 20-31.

Stegink, L.D. "The aspartame story: a model for the clinical testing of a food additive." The American Journal of Clinical Nutrition. 1 Jul. 1987, Volume 46, Number 1: 204-215.

Reference this article:
Dunning, B. "The Truth about Aspartame." Skeptoid Podcast. Skeptoid Media, 11 Nov 2008. Web. 3 Sep 2015. <>


10 most recent comments | Show all 174 comments

Yeah, but that doesn't mean the amount in either type of food is even remotely toxic. And the amounts of methanol referred to are the amounts that are absorbed into your body after digestion, not in the actual food. Ethanol would neutralize methanol during *digestion*, so that effect is cancelled out - with all that into account, an apple STILL doses you with 1.5 times more methanol than a can of Diet Coke.

That also happens to illustrate that you need to consume more ethanol than you did methanol to turn on the inhibiting effect, and chemically that makes perfect sense (an excess of reactant drives the reaction).

Your body deals with background amounts of many chemicals that are toxic in large quantities and happen to show up in food or food digestion (methanol and formaldehyde in particular), and that's a fact. Deal with it and stop being paranoid over nothing.

nonpseudoscientist, Portland, OR
May 25, 2013 1:51pm

Hard to believe that anyone is as naive as brian dunning - especially with personal case histories. I think he is a corporate shrill. I will believe the original FDA - the doctors and scientists and the case studies.

I recommend brian drinks 10 cans of diet cola per day for 1 month and puts his words to the test - then he can get back to us if he can still write.

charles allan, glasgow
July 20, 2013 8:17am

Well, as my wife will attest, that's a pretty fair estimate of how much Diet Dr. Pepper I do drink on a daily basis, and have for many years. We all have our vices. :-)

Brian Dunning, Laguna Niguel, CA
July 20, 2013 12:18pm

I drink at least a liter of Coke Zero every day. I'm all fine and dandy.

Juan Pablo Santos, Quito
October 30, 2013 6:29pm

What does Brian Dunning, Hummer Winblad Venture Partners and Monsanto have in common?

James Izbinski, Toledo, Ohio
October 30, 2013 7:31pm

As-part-a-me I have no reason to lie. I've been drinking this stuff as long as it's been out. Hasn't affected me any. I can read teleprompters better than anyone else. I can tell you that my ego devised ObamanatorCare will correct any deficiencies that Diet Pop produces. I'll bet you didn't know that not only did Al Gore invent the internet he invented Nutrasweet. Nutrasweet helps keep you focused on politics and keeps you from rambling on about nothing like what I do everyday. What I say to you all out there if you're able to follow me because of my incomplete clarity and my ability to fly on a big plane and travel the world to get exotic meals and free overnight lodging at the world's best resorts cause I'm better than all of you and you're all so ignorant about what is happening to you all because you haven't drunk enough Diet Soda to help you think like me. And you know that I'm so smart I'll be writing my next book on how I screwed you all because sure as black is in the white house I'll keep doing the things I do cause I need attention and like partying with the rich and famous and you're gonna see me starring in my own movies. I'm gonna buy B.E.T. and merge with Oprah and have a talk show all scripted and put on teleprompters to make it easy for me to look smart. Buy the time you have read this you'll have forgotten all about what was being discussed here. That's the beauty of distraction that I'm so good at! I know you'll vote for me again. I am Amuslika.

Barrie Soetoro, Kenya, Indonesia
November 2, 2013 12:03pm

All artificial sweetners are deadly.

It's God way of telling us that we need to eat more sugar.

Swampwitch7, Gainesville Fl
August 14, 2014 10:37am

I see a lot of pro and con here. Most of the anti-aspartame comments come from people posting anecdotal evidence or indicating research studies which they likely do not understand. Let's see what the National Cancer institute has to say, as they probably do have a good understanding of the various research studies:

"Do artificial sweeteners cause cancer?
No. Researchers have conducted studies on the safety of the artificial sweeteners (sugar substitutes) saccharin (Sweet 'N Low®, Sweet Twin®, NectaSweet®); cyclamate; aspartame (Equal®, NutraSweet®); acesulfame potassium (Sunett®, Sweet One®); sucralose (Splenda®); and neotame and found no evidence that they cause cancer in humans. All of these artificial sweeteners except for cyclamate have been approved by the Food and Drug Administration for sale in the United States. For more information, see the NCI fact sheet on Artificial Sweeteners and Cancer."

Canyon, Verde
August 16, 2014 11:47am

Check your facts people; Donald Rumsfeld quit the company after 2 failed attempts to get Aspartame approved. He then got a job in the federal government as the head of the FDA and voila the next application for approval was approved. The rest is neuro-toxic history

JAson, Vancouver
October 24, 2014 1:12pm

Hey man, the story behind the approval of aspartame is shady at best, really shady with really powerful people behind it.
For every pro aspartame peer review there's another one against, however you straw-man defend it, making it sound like people who doubt it have no grounds or there are no valid researches.
For instance you say a fringe minority is against aspartame, well my friend outside of the media bubble of the US, like my country or Europe, safety limits on consumption and a lot of tests against have been done? Are they not valid?
Why did your FDA (or whomever) resisted so hard the approval of the substance and why was it approved in such a shady way?

Now I find your skepticism honest most of the time and condescending and simplistic some other times but over all like your show.

My question is, given its inception, the way it was approved, the equal debate on if it on both sides and the fact that is an absurdly artificial thing not worth mentioning or taking a more neutral stance? Yeah small doses might be negligible, but aspartame is in everything from food to medicine in not so innocuous amounts, Metamucil is 51% aspartame... if you add it all up? Medicines, food doesn't it warrant a more neutral stance instead of making the opponents sound like looneys?

You made it sound like the debate is as one sided as global warming(or the modification of weather systems) is that also false?

Daniel, Heredia
May 5, 2015 11:30pm

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