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The Huffington Post recently posted an article by Joseph Mercola which appears to be intended to be about how aspartame manufacturers have rebranded it in an effort to mislead the public (Mercola 2010 []). The author uses this as a jumping off point to make a large number of claims about the dangers of aspartame, much of which is uncited or outdated. In this article, I will respond to the claims with updated information (when available) and point out where there appears to be no credible source at all for the claim. Carl Sagan put best what will be a major theme of this article: “extraordinary claims require extraordinary evidence.”
The article starts light by stating the approval of aspartame was the “most contested” in FDA approval history. As proof, there is a link to the author’s own article (but not stated as such). I would not be surprised to find that nearly all major food additives go through a contentious process, and aspartame was no different. And they should, as this is a matter of safety and all concerns must be heard.
There is certainly still controversy over aspartame and its history, but it seems to be the stuff of conspiracy, not science. In any case, aspartame has been approved by the FDA, and has been safely in use for more than 20 years.
Mercola then moves on to the extraordinary claim (for which no references are provided) that aspartame was once listed as a “biochemical warfare agent claim”. I did manage to find another article on mercola.com where he makes this claim and appears to cite a source as a footnote reference. But there is no actual list of footnotes on that article, so there is no way to check here. Aspartame is most definitely not listed as a biochemical warfare agent and, without credible evidence stating otherwise, it seems unlikely that it ever was in a meaningful way.
There is a small section about how some manufacturers have chosen to rebrand aspartame. Based on the title of the whole article, it seemed that this was one of the major points, but it does not take up much space. The gist is that the manufacturer Ajinomoto has rebranded aspartame as “AminoSweet”. It is already also known as NutraSweet and Canderel, so I am not certain what the argument is here. I suppose if one is assuming that aspartame is dangerous and that manufacturers need to “hide” the true nature, then it seems like something he would be mad at. But in no way is the danger demonstrated in this article.
Aspartame Wreaks “Havoc” On Your Health?
After the initial remarks about the history and name change, Mercola moves onto the heart of the article: claims about the dangers of aspartame consumption. This section mainly makes the claim that there have been thousands of complaints to the FDA about side effects of aspartame, and that this demonstrates that it is not safe. In the words of Mercola:
Did you know there have been more reports to the FDA for aspartame reactions than for all other food additives combined?
In fact, there are over 10,000 official complaints, but by the FDA’s own admission, less than 1 percent of those who experience a reaction to a product ever report it. So in all likelihood, the toxic effects of aspartame may have affected roughly a million people already.
This is another claim for which a reference (to the FDA in this case) would be appropriate. This one did not warrant even a link to mercola.com despite forming the basis of the entire section. Searching the Internet a bit, it is possible his source is something like this apparent portion of an email from “Betty Martini” (a person or alias that you can find quite a bit of anti-aspartame content on the Internet). You may notice that this is a link to a page hosted on fda.gov. This is not FDA-sponsored material, but rather comments and documentation that consumers can submit (FDA 2010[]) as part of the approval or petition process. In makes reference of an “official” FDA compilation of 10,000 complaints, but does not actually link to the list. Again, however, this extraordinary claim is not backed by actual evidence.
The FDA does in fact have an Adverse Event Reporting System (AERS), where you can go and report effects you believe you’ve had (and naturally people have reported aspartame). The FDA uses this to compile a list of “potential” dangers that consumers and health officials should be aware of (FDA 2010, Potential[]). However, you won’t find Aspartame listed in that current set. Or for that matter on any of the warnings from 2008 to 2010.
I think it is useful to quote from the FDA here about what the AERS is and is not as it relates to causality (FDA AERS []):
AERS data do have limitations. First, there is no certainty that the reported event was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event. Further, FDA does not receive all adverse event reports that occur with a product. Many factors can influence whether or not an event will be reported, such as the time a product has been marketed and publicity about an event. Therefore, AERS cannot be used to calculate the incidence of an adverse event in the U.S. population.
If you would like to dive into the actual complaints available, there are data files you can download. If aspartame were such a danger, there should be at least a few references for aspartame, but I don’t find any. You will however find aspirin in there, which makes sense as it is a potent and effective drug[].
He lists the various neurological disorders that aspartame apparently causes, but the majority of these are diseases and disorders for which the the medical community does not have a known cause or cure. So there is no way to definitively say “aspartame did not cause this.” However, aspartame most definitely is not in the running by any established or credible research agency into any of these diseases. Tollefson and Barnard did an analysis in 1992 of the 900 or so claims available at the time. They only looked into seizure related ones and found that the data “did not support the claim” of a linkage to seizures and aspartame consumption (Tollefson []). A more overarching review was done by the CDC, and also found no reason to suspect a “widespread public health hazard” (but cautioned that were a small number that could be attributable to aspartame) (Bradstock 1986 []).
Mercola makes another remarkable claim:
Unfortunately, aspartame toxicity is not well-known by doctors, despite its frequency. Diagnosis is also hampered by the fact that it mimics several other common health conditions, such as [Multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, Fibromyalgia, Arthritis, Chronic fatigue syndrome .. Birth defects..]
In one statement, Mercola discounts the medical community at large’s ability to diagnose and recognize illnes and suggests and inability to recognize “aspartame toxicity”. This is a striking statement to make about the medical community. MDs (Dr. Mercola is a DO) are going to try their hardest to determine what causes ailments of their patients. If aspartame were a major concern, they would be aware of it.
This section based its claims on the idea of a massive wealth of documented evidence of side effects. This evidence was not provided. That is not to say that the FDA does not receive complaints about aspartame (probably more so in the past shortly after it was approved). But the available data do not indicate that the complaints have continued, nor is it recognized as being any sort of potential danger by the FDA or the CDC.
Diet Food and Drinks “Cause” Weight Problems?
Mercola then moves onto the claim that low-calorie drinks actually lead to obesity and weight gain. He again makes what looks to be a reference to prove his claim, but it is in fact another link to one of his own articles on mercola.com (which would be fine, except that it does not make it clear). Following the link, he references a study by Purdue University researchers published in Behavioral Neuroscience. In the study they tested whether or not rats would increase their calorie intake when a sweet taste was disconnected from actual energy content of the food (via non-nutritive sweeteners). They found that the results suggested the possibility that people could have increased obseity via those means (Swithers []).
We at last have a situation where Mercola has (indirectly) cited an actual study to back his claims. However it represents a single study done on rats in a slightly contrived situation. A later systematic review of the larger body of research in humans (as well as rats) have found that in humans, non-nutritive sweeteners (NNS) do not generally seem to lead to increased energy intake due to confusing signals (emphasis mine) (Mattes []):
Thus, short-term trials of NNS consumption provide mixed evidence supporting reduced energy intake, whereas longer-term trials consistently indicate that the use of NNS results in incomplete compensation and slightly lower energy intakes. The latter studies are arguably the more nutritionally relevant.”
The authors response to that specific rat study:
In one set of studies [Purdue]…It is unclear whether these findings can be extrapolated to humans who eat a more varied diet and when nonnutritively sweetened foods are ingested concurrently with high-energy foods (eg, diet soda with a hamburger, nonnutritively sweetened coffee with pie). Under such conditions, associative learning would be considerably more complicated and subtle. …
Other recent evidence indicates that learning does occur in humans, but is counter to predictions from the animal studies (153)…In short-term tests, participants failed to report increased appetite or energy intake in response to consumption of NNS, whereas nonusers of NNS reported heightened appetite and energy intake after such stimulation. These findings indicate inconsistent exposure to NNS (paired or not paired with energy) from beverages results in blunted responses to their consumption and no elevation in risk of weight gain..The implications of chronic, widespread use of NNS on taste-energy associations and their influence on appetite and feeding are questions open to study.
So based on a larger body of evidence, it seems that for users who do not frequently consume diet content, their senses won’t quite be used to the disconnect between the sweet signal and calorie content. However, it does not seem to actually lead to additional weight gain. Mercola did provide some evidence here, but it appears to be outweighed by a larger volume of studies directly relevant to humans though as always “more studies are needed.”
It get worse?
In the next section, Mercola continues about the apparent dangers of aspartame, which he has written a book about and encourages readers to get for their “loved ones”. He also restates that about two-thirds of side effects being neurological in nature, when more accurately it would be two-thirds (or whatever the figure might be) of claimed side effects. There are a couple of paragraphs discussing potential chemical reactions from aspartame that might lead to side effects in the brain. However the theories are un-sourced despite the specificity of the claims. Mercola mentions specifically migraine headaches and brain tumors.
While there were some early very small studies that seemed to link aspartame and migraines (Koehler 1987[]), larger controlled studies found aspartame no more likely to lead to migraines than placebo, including in those who already believed they had aspartame-caused headaches (Shiffman 1987[], Garriga 1991[]).
As for brain tumors, it is likely that what Mercola has in mind is an infamous (and heavily criticised) data analysis performed by JW Olney (Olney 1996[]). The study purported to demonstrate a marked increase in the incidence of brain tumors in the years following the approval of aspartame. The analysis has been criticised for choosing the years in such a way that the increase would seem to coincide with the approval, when in fact the increase started before aspartame was introduced, and has declined since (Butchko 2001[]). Olney did not actually compare those who consumed aspartame with those who did not. A case-control study printed in the Journal of the National Cancer Institute was unable to reproduce any relationship between brain tumors (in children, who would be more sensitive) and aspartame (Gurney 1997[]). It seems unlikely that the FDA would have kept aspartame on the market if there was any credible link between it and tumors, and presumably the Journal of the National Cancer Institute would not be pointing out the lack of effects.
Given that there has been no credible causal link between aspartame and any actual disorder, it is interesting that the article continues: ”
One of the reasons for this side effect, researchers have discovered, is because the phenylalanine in aspartame dissociates from the ester bond.”
Again, no source is cited for this very specific claim, so it is hard to actually look into. Additionally, this is an argument about phenylalanine (a component of aspartame), not aspartame. Any relationship would need to be identified with the whole, not its parts. Before attempting to identify the causes of “aspartame toxicity”, it would seem prudent to first demonstrate that aspartame toxicity actually exists.
Mercola then moves on to the idea of “excitotoxins”: “The aspartic acid in aspartame is a well-documented excitotoxin. Excitotoxins are usually amino acids, such as glutamate and aspartate. These special amino acids cause particular brain cells to become excessively excited, to the point that they die.”
Note again that this is referring to specific components of aspartame, not the whole. In any case, if you perform Google search for “excitotoxin”, you won’t find results that suggest that this is a mainstream idea within the medical community. While excitotoxity may be a valid idea, it does really seem to be appropriate to link it to aspartame. Excitotoxity seems to be mainly used to claim harmful effects of MSG (via glutamate). The two main researchers in the area are John Olney (who coined the term) and Russell Blaylock. Searches on those names (especially Blaylock) turns up interesting results which, to me, do not put them into the mainstream.
Dr. Mercola continues…
Excitotoxins can also cause a loss of brain synapses and connecting fibers. A review conducted in 2008 by scientists from the University of Pretoria and the University of Limpopo found that consuming a lot of aspartame may inhibit the ability of enzymes in your brain to function normally, and may lead to neurodegeneration.
According to the researchers, consuming a lot of aspartame can disturb:
- The metabolism of amino acids
- Protein structure and metabolism
- The integrity of nucleic acids
- Neuronal function
- Endocrine balances
The review cited brings up methanol and the other “suggested” cause of “certain mental disorders” (Humphries 2008). It is in a peer reviewed journal, and I am not qualified to analyze it (nor do I have access to the full text). That said, it is not frequently cited and one of the few citations is actually a printed response from the same journal: “The premise of the review, that the high-intensity sweetener aspartame is neurotoxic, ignores a very large scientific literature to the contrary“ (Fernstrom 2009[]). Much of scientific credibility is based on the notion of having your results cited and reproduced. In the case of the Humphries study, there is already prior overwhelming evidence of no link and so their analysis is out of step.
Mercola throws in a reference to the common claim about the dangers of aspartame with regard to formaldehyde. I just recently addressed this specific issue by looking at the studies around this claim, and there seems no reason to be concerned (Dewald 2010[]). Despite the scary sound of “formaldehyde”, it is actually a completely normal part of the daily metabolic process, being produced in the amount of about 1.5oz a day (Formaldehyde Council 2007 []). Additionally, fruits and juices lead to a significantly higher volume of formaldehyde (Magnuson []) than aspartame.
Dr. Mercola makes a quick foray into the claims that aspartame is a carcinogen. He links to his own article discussing a European Ramazzini Foundation study (Soffritti 2006 []) attempting to link aspartame to tumors in rats. The article mentions that the European Food agency and US FDA intended on reviewing the study. Well, they did review it (FDA 2007[]) and found (European Commission 2002[]) that it was not of sufficiently high quality or controls to demonstrate a cancer risk, and affirmed the continued safety of aspartame. So this is another case where the article does at least cite a source, but it is either outdated or heavily criticised by the scientific and health community.
As part of his discussion on the apparent carcinogenicity of aspartame, Dr. Mercola makes reference (via mercola.com) to a “compelling case study” of a woman named Victoria Inness-Brown, who did a study of rats and demonstrated it caused tumors. It might strike you that the body of research on this topic is so sparse that he is forced to reference private citizens doing “research” which is even difficult for experts to perform. I challenge the reader to actually locate this study. It certainly wasn’t published in a journal (peer-reviewed or not). The only references I can find about it are old links to it, which now point to a generic landing page featuring credit card ads. But even reading his description I am suspicious. What happened in the control rats? The previously mentioned discredited Soffriti is the only study that seems to have legitimately attempted to look into this matter, and it was clearly found wanting.
How does one cure oneself of the desire for sweets?
In the next section, things take a bit of weird turn. Dr. Mercola discusses “Nutritional Typing™”, which is an offshoot of “Metabolic Typing” (a quiz-based approach apparently designed to determine the diet “tailored” to your metabolism). He provides a reference, which is again a link to an article on mercola.com which seems to be a long form ad for a book written by Dr. Mercola on how to determine your “Nutritional Type”. It is also possible to become certified in this technique, for a sum of money.
Dr. Mercola also mentions his solution for removing food cravings altogether in the form of his Meridian Tapping Technique (MTT). If you followed his reference (to a mercola.com page), you will come across the following quote:
Some people are initially wary of these principles that EFT [the former name for MTT] is based on – the electromagnetic energy that flows through the body and regulates our health is only recently becoming recognized in the West. Others are initially taken aback by (and sometimes amused by) the EFT tapping and affirmation methodology, whose basics you will learn here.
There is absolutely no scientific basis for the concept of “meridians”. They, their purpose, or their effects have never been found. It would quite reasonable to be “wary” of those principles he espouses until such time as controlled studies have been done that actually detect meridians or their properties. Bringing up meridians brings to mind acupuncture and other alternative claims using “Qi” (the supposed “energy flow” or “vital energy” brought from traditional Chinese culture, and frequently used as explanation for non-scientific beliefs) for which there is no scientific basis and for which scientific studies can find no effect above that of a placebo (Madsen 2009 []).
By way of evidence of how MTT is popular among practicing doctors, Dr. Mercola points out doctors who who have started using his MTT technique. The list does not include MDs (or even DOs as far as I can tell). The list is actually made up of:
- Natural Health Clinics
- Naturopathic Physicians
- Pain Therapists
- Emotional Therapists
Dr. Mercola also sells books and DVDs available for purchase to be able to fully harness the power of EFT/MTT.
This section seemed to be clearly the least objective of the article. The majority of it was made up of Dr. Mercola’s pointing to products and services made available by him and his company. No references are made to whether or not the techniques are scientifically credible or valid. They might be, but he offers no evidence. By now things have veered away from claims about the safety of aspartame.
An “acceptable” alternative?
Considering the tone of the rest of the article, it was surprising that Dr. Mercola would actually endorse any artificial sweeteners. But he does at least approve of Stevia, because it is a “safe, natural alternative” sweetener from a plant.
Yes, Stevia is “natural”, but is has had quite a bit of controversy itself. It was only in December of 2008 that the FDA gave it the “Generally Recognized as Safe” label (Curry 2008 []). Stevia is still banned from usage in the European Union (Stevia Association []). Recommending Stevia appears to me to be part of the common “natural fallacy” of regarding any substance that is closer to its original form as being somehow better than things which are “artificial” (even if the synthetic substance is chemically identical). There is plenty to be found in nature that is unsafe — arsenic, hemlock, poison ivy are some quick examples. While Stevia may actually be safe (and is approved in the US), it seems that Dr. Mercola recommends it purely on the grounds of it being “natural” despite having much less of a clinical track record of safety. Long term traditional usage is not the same as evidence.
The most common response to this article may be personal anecdotes of those who believe they were/are adversely affected by aspartame. To those, I just ask that you carefully read the studies which have looked for evidence of the plausibility and occurrence of it, and found none. It is human nature to look for patterns, and aspartame is so prevalent that removing it from your diet is not an isolated situation. Making that change removes any number of other habits and substances. Only your doctor could really help you determine what is causing migraines, seizures, etc.
Dr. Mercola’s article unfairly attacks aspartame, an artificial sweetener recognized and affirmed as safe by the FDA and used daily by millions of people without ill effects. I felt it important to point out the inaccuracies in the claims (and call for evidence of others) because if consumers get the impression that common products (be it food additives, medicines or medical practices) are unsafe they may seek out alternative treatments which have not been found to be safe, or may even have been found to be harmful.
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