Nov 01 2007

Aspartame Safety and Internet Urban Legends

A chemical found in thousands of products is causing an epidemic of severe neurological and systemic diseases, like multiple sclerosis and lupus. The FDA, the companies that make the product, and the “medical industrial complex” all know about the dangers of this chemical but are hiding the truth from the public in order to protect corporate profits and avoid the pesky paper work that would accompany the truth being revealed. The only glimmer of hope is a dedicated band of bloggers and anonymous e-mail chain letter authors who aren’t afraid to speak the truth. Armed with the latest anecdotal evidence, unverified speculation, and scientifically implausible claims, they have been tirelessly ranting about the evils of this chemical for years. Undeterred by the countless published studies manufactured by the food cartel that show this chemical is safe, they continue to protect the public by spreading baseless fear and hysteria.

I could be talking (albeit sarcastically) about any of countless urban legends and false fears being foist on the public, abetted by the rapid communication afforded by the internet. But in this case I am talking about aspartame, an artificial sweetener in use since the early 1980’s. The notion that aspartame is unsafe has been circulating almost since it first appeared, and like rumors and misinformation have a tendency to do, fears surrounding aspartame have taken on a life of their own.

I am frequently asked my opinion about the safety of aspartame. Nutritionists often council to avoid the sweetener, citing unverified claims that it is unsafe. I was recently sent a chain letter warning that aspartame causes MS (which of course can be cured by simply avoiding aspartame), and Snopes informs me that this particular letter first appeared in 1998.

There are also hundreds of websites dedicated to smearing this much abused food additive. One site, run by Dr. Janet Starr Hull Here (she has a doctorate in Nutrition), responds to the latest report of aspartame’s safety by writing:

I will never accept the news of aspartame safety. I think it is a “business” decision to discredit/discount the research results that aspartame DOES cause cancer, major nerve disorders, birth defects, and brain imbalances. Think about it – can you imagine the chaos that will occur when the truth of aspartame dangers is accredited. The FDA has known about the dangers, the corporations have known about the dangers, and the medical community (if it is really worth anything) has known about the dangers.

The statement that “nothing will ever convince me” is a huge red flag that someone is defending an ideological position, one immune to evidence or reason. Admittedly, in context it could be a clumsy statement that something is very unlikely. It would be very difficult to convince me that the earth is flat – I’m really saying that the existence evidence is overwhelming that the earth is not flat. But that is not what Dr. Hull is saying. She is specifically saying that she will dismiss any evidence that is contrary to her belief that aspartame is not safe on the a-priori basis that such disconfirming evidence is part of a vast conspiracy.

What evidence does she have for such a conspiracy? The argument from final consequences logical fallacy – big industry wouldn’t want it. It’s also not very plausible. Products get pulled from the market all the time when new evidence suggests they are not safe. Also, the final safety net for the consumer is legal liability. Class action law suits have bankrupted companies, even when the underlying claims were false. Imagine if they were true. Look how much the tobacco industry has had to fork over.

Now I am not arguing that corporations are all good corporate citizens or wouldn’t dream of sweeping some inconvenient evidence under the carpet. But I am saying that a decades long conspiracy among industry, federal regulatory agencies, the medical community, and multiple research institutions and individual researchers – all under the nose of the press and lawyers looking for big class-action suits – is implausible in the extreme. I am also arguing that we should fairly assess all the evidence, not just cherry pick the evidence we like and dismiss the rest out of hand.

What does the evidence say about aspartame? A recent published review of all available evidence, including hundreds of studies, concluded:

The studies provide no evidence to support an association between aspartame and cancer in any tissue. The weight of existing evidence is that aspartame is safe at current levels of consumption as a nonnutritive sweetener.

Multiple reviews, going back to 1985, conclude the same thing. Like all such research, there is noise in the data – but no signal. There is no pattern of evidence to suggest that aspartame causes cancer, autoimmune disease, neurological disease, diabetes, or anything else its critics claim. One Italian researcher has found an increased incidence of cancer in rats exposed to high doses of aspartame, but this is contradicted by numerous other studies -so the weight of the evidence is still negative.

As I have noted before – you have to interpret a literature, not a single study. The results of one lab or one study can be erroneous. When decades have produced hundreds of studies on a question, the cherry pickers will always have a lot to choose from. That is why systematic reviews are necessary, and in this case the reviews are all negative.

One noted exception is that aspartame does seem to cause headaches in some people. These headaches are not dangerous or a sign of toxicity or other problems, they are just an annoying symptom. So if aspartame gives you headaches, use Splenda or some other sweetener. Also, aspartame should not be used by those with a rare condition known as phenylketonuria since they cannot metabolize aspartame properly (and products with aspartame always contain the proper warning. Otherwise, don’t worry, aspartame is safe.

Unfortunately, the misinformation and conspiracy mongering is out there, in the inter-tubes. But so is reliable information. This situation is not likely to change, which means the only solution is for the public to become more internet savvy – meaning more skeptical.

17 responses so far

17 Responses to “Aspartame Safety and Internet Urban Legends”

  1. Carpe Vitaeon 01 Nov 2007 at 2:38 pm

    Did you hear the interview of Devra Davis, the Director of Center for Environmental Oncology at the University of Pittsburgh Cancer Institute’ by NPR’sTerry Gross:

    She called aspartame a “Ticking Time Bomb”. See for some of her comments.

    I don’t recall the details of the interview. I don’t believe that she claimed there was evidence it did cause cancer, only that she was suspicious and said that many of the studies to date had flaws (demographics, amount of product consumed, etc.) But the way she worded it, and given her credentials, I can see many people now believing aspartame is a carcinogen.
    – Doug

  2. Binnebrookon 01 Nov 2007 at 6:46 pm

    Thank you for the piece on aspartame. I do find that if I have too much of it — more than 12 ounces of diet soda, say — it has an unpleasant digestive effect, to wit, cramping and intestinal gas.

  3. EmilyBon 01 Nov 2007 at 7:38 pm

    I also heard this interview- she said that the Italian study was important because it followed the mice not just for a short period of time (I believe most studies followed 1 or 2 years), but until their death. Basically making the point that aspartame won’t kill you right away, but it will get you eventually – and therefore we have yet to see the negative effects of the rising use of aspartame over the past few decades. I also thought that, given her credentials, most people listening would take it as truth.

  4. ellazimmon 02 Nov 2007 at 1:56 am

    If these people really feel there is a problem then why don’t they run their own study? They could probably scare up the money from their followers (what an apt turn of phrase) or some foundation or university. They would be vindicated, their reputations would be hugely inflated and they would save us all from dying hideous deaths. Or have they looked at the statistics and noticed no corresponding increase in deaths by cancer in the last 20 years? Oh wait, the mortality statistics are being manipulated, I forgot. And their paper would be suppressed of course. Gosh, this is a pretty cool paradigm actually. I never really trusted anyone in the first place. Let’s see: the government (which is controlled by the Illuminati) is suppressing the data about UFOs, killed over 3000 people by controlled explosions at the World Trade Center (why did they need the planes again?) and is also trying to kill us with aspartame, fluoridation and mercury laden vaccines, right? Which is why they shot Kennedy or . . . wait . . . I’ll think of something . . .

  5. Nitpickingon 02 Nov 2007 at 7:55 am

    EmilyB wrote, “I also heard this interview- she said that the Italian study was important because it followed the mice not just for a short period of time (I believe most studies followed 1 or 2 years)…”

    Mice only live for up to two years in a lab. Maybe the studies used rats, which I believe have a longer potential lifespan?

  6. moiraeon 02 Nov 2007 at 10:25 am

    I haven’t seen the interview you mention but have also received emails regarding this subject. The part that I’d like you to address is that in the email I received it does not say aspartame causes ms but that if aspartame gets too hot it metabolizes into Formaldehyde and that is what is supposed to cause ms-like symptoms. Will you expand more in that area?


  7. jimon 02 Nov 2007 at 11:39 am

    I think it must be remembered that the study with rats, was just that, a study with rats. it seems obvious that the rats did get cancer, from looking at the research I have no reason to doubt it. But rats are different from humans in many ways. They live shorter lives, eat a greater percentage of their body weight per day.

    It seems the apporpriate level of concern was shown about the rat study, but that further studies did not back up such an affect on humans.

    You could see this as similar to the effect chocolate has on dogs. Chocolate appears to be quite toxic to canines, that doesn’t mean humans should all stop eating it thankfully 🙂

  8. Nathan Mahoneyon 02 Nov 2007 at 10:58 pm

    It’s possible that people are confusing or conflating aspartame with saccharin, which does indeed have a carcinogenic profile–in rats, but not humans.

    Remember this warning stamped over anything containing saccharin: “Use of this product may be hazardous to your health. This product contains saccharin, which has been determined to cause cancer in laboratory animals.” For years people were reading that warning, 1977-2000 (the warning has since been removed in light of human epidemiological studies). It’s perfectly reasonable for someone to assume that cancer in laboratory animals means a good chance of cancer in humans. That’s 13+ years of bad press. It’s difficult for people to forget what they’ve known for so long and be re-educated to the contrary opinion, whatever the evidence or the individual’s skeptical composition*. Moreover, even after being (re)taught, people often regress to their earlier misconceptions. This is well-documented in the education literature.

    *This does not explain the crackpots, but I bet it does explain the majority of the populace. Of course all the crap on the interweb doesn’t help matters, as Steve says. The best we can do for the masses is get the correct information out there in as many places as possible. It’s more about marketing than logic and evidence.

  9. Steven Novellaon 03 Nov 2007 at 8:30 am


    I agree that what you describe is how conspiracy theorists in general (and this case also) arrive at their conclusions. But that is not how they justify their conclusions. I was addressing the logic by which she justifies her conspiracy conclusion.

    And I do think it is an argument from final consequence – a subtype related to the “cui bono” or “who benefits” subtype? The argument is that if someone benefits from some thing then they caused the thing. The conspiracy argument is the flip side of this – if someone would be harmed by something then they are engaged in a conspiracy to cover it up. Both subtypes are dependent upon final consequences, so I think they are subtypes of this fallacy.

  10. matt gon 03 Nov 2007 at 11:07 pm

    Hey Steven,

    Thanks for posting this. I remember when I was first diagnosed with MS in 2005, it took about a month before my (well meaning) father encountered and forwarded me the Aspartame scare chain email.

  11. ziggyon 04 Nov 2007 at 3:31 am

    I’m one of those who get headaches from aspartame. It takes about 10 – 15 minutes to kick in. I’m not sure if I’d call it a migraine, but there is some light sensitivity with it.

    On a different note: I used to work as a research assistant for a biochemistry professor. I can’t remember the details but he pointed out a metabolic pathway in the eye (his specialty) where aspartame could be metabolized with one of the metabolites being methanol. Methanol, of course, is NOT something you want in your eye! I’m not sure if aspartame would ever reach the eye (there is a blood/eye barrier much like the blood/brain barrier), nonetheless he would never touch the stuff and discouraged others from using it.

  12. abartleyon 05 Nov 2007 at 5:36 pm

    I almost asked about your views concerning aspartame on the Skeptic’s Guide website a few weeks ago. The ms/lupus and the cancer email have both been posted in the general staff inbox at my work. I have tackled it and discusses the poorly presented evidence that this email purports to have. Although the New Age counselor who sent it out maintains the belief, I do believe I was able to help alleviate some fears of those who were being swayed by the letter. The year before the same counselor sent out the aspartame is causing cancer letter. This was the first letter where I felt comfortable enough to challenge the info and really won some support among the faculty for my skepticism and evidence-based thinking.

  13. Cayon 05 Nov 2007 at 10:29 pm

    I heard the interview of Devra Davis too. And like you all, she got me wondering about her legitimacy. She seems to have that combination of credentials and credulity that leads people astray.

    And a comment on aspartame. A friend once told me that she gets regular soda for her kids instead of diet because “you don’t know what the sweetener is going to do to you.” I still wish I’d responded “Yeah unlike regular soda, which we know can give you obesity and diabetes.”

  14. Steven Novellaon 06 Nov 2007 at 2:17 pm


    You make good points, but I think you are premature and unfair in your accusation of “very apparent bias.” I have no bias of which I am aware on this issue. I simply was reporting the consensus opinion. I did not discount the Italian study – it is evidence, the methods seem valid, etc. I simply pointed out that the weight of the literature is negative, and every formal review of the literature has reached this same conclusion. More studies may move the evidence in the direction of a connection, we can only wait and see.

    My choice of links is often based in what I can find with the time I have. Putting out a blog like this 4-5 times a week does not afford impeccable attention to detail. To balance this, however, blogs are also not written in stone – so I can add more or better references, or address questions or vague points that readers bring up. It’s the nature of this medium. So don’t read too much into my choice of reference links.

  15. ruralmysterieson 08 Nov 2007 at 5:30 pm

    The anti-aspartame Web sites like to cite FAA cautions that pilots not drink diet soda on-the job and an article warning against aspartame that appeared in General Aviation News. Neither is true.

  16. verena_doon 13 Dec 2007 at 11:24 am

    Thank you for addressing this issue. The idea that aspartame is really bad for you/causes brain tumors/causes MS etc. seems remarkably persistent. I periodically do a check on Medline and so far have found nothing that would discourage me from drinking diet soda. I suspect there is some moralism behind the ideology…

  17. mjeppsenon 15 Feb 2008 at 3:42 pm

    Thanks for posting on this, Steven. I noted today what looks like a new study (2008.02.15?) with rats that showed some pretty dreadful results of the sweetener:

    I’m no scientist, but the methods of the study seem to be pretty rigorous at first glance. Some analysis here:

    I’m curious what you folks think of this info and if you think it will have any effect (either way) on the current consensus of the scientific community.


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