Topic: For Pug: Aspartame is not carcinogenic.

[WindAndConfusion]

http://annonc.oxfordjournals.org/cgi/reprint/15/10/1460

[From the abstract:]
Despite some rather unscientific assumptions, there is no evidence that aspartame is carcinogenic. [...] For new generation sweeteners, it is too early to establish any epidemiological evidence about possible carcinogenic risks. As many artificial sweeteners are combined in today’s products, the carcinogenic risk of a single substance is difficult to assess. However, according to the current literature, the possible risk of artificial sweeteners to induce cancer seems to be negligible.

[... Main text, page 4:]

Fifteen years after the approval of aspartame, the Journal of Neuropathology and Experimental Neurology published an article by Olney et al. [31] with the title ‘Increasing brain tumor rates: Is there a link to aspartame?’, which received tremendous attention from the mass media, as well as the scientific community. The authors hypothesized that the increasing rate of brain tumors in humans since 1980 could possibly be explained by the introduction of aspartame. They supported their hypothesis with an FDA trial in 320 Sprague – Dawley rats. Twelve ratsdeveloped malignant brain tumors after receiving an aspartame-containing feed for 2 years [32]. They argued that another trial had shown that the aspartame molecule acquires mutagenic activity when nitrosated [33]. The publication of Olney et al. [31] led to heavy criticism of the scientific community, whereas the laymen press suggested abstaining from aspartame-sweetened products [34]. In an editorial, Ross [35] demonstrated the weaknesses of the Olney study. He explained that Olney et al. [31] linked two events that incidentally occurred during roughly the same time period: the increase of brain tumors and the introduction of aspartame. This correlation is not admissible in epidemiology, and is called ‘ecological fallacy’. There was no information available regarding whether the individuals who developed brain tumors consumed aspartame. As Ross states, one might also invoke home computers, VCR usage or the depletion of the ozone layer to argue trends in brain tumors. In addition, the introduction of aspartame and the rising brain tumor rate occurred almost simultaneously. For the development of brain tumors, a certain latency would have been required. The study that showed an increased brain tumor incidence in aspartame-fed rats, which gave rise to the argument of Olney et al., could not be confirmed by later trials [36].

[Xessive]

I'm aware that it's not specifically carcinogenic, but is it a mutagenic agent?

[WindAndConfusion]

Without bothering to quote the authors, I'd say no, because mutagens themselves tend to cause cancer and these studies should have been sensitive enough to pick that up if there was any significant effect. Without correlation, you can't really argue for causation.

There's another criticism that centers around its supposed neurotoxicity, but there's some evidence against that, too (which I'm currently trying to get a hold of).

[poomcgoo]

I already posted about this.  It's not carcinogenic.  It contains the amino acid phenylalanine, which can be harmful if you have phenylketonuria, which is the body's inability to convert phenylalanine to taurine I believe.

Aspartame isn't the only artificial sweetener either.  Others, like saccharin and cyclamate have been considered carcinogenic in the past as well, but also aren't.

[Pugnate]

Ok cool man. Thanks.

[Quemaqua]

Though there are still plenty of studies that indicate it does a lot of bad things.  I was reading something not long ago about aspartame being linked to causing seizures, and it was a pretty convincing study.  Can't remember where I read it, though.

[Cobra951]

When aspartame, aka nutrasweet, first came out, it was marketed as "all natural".  From the ads, you'd get the impression that it brought as much goodness as an orange off a tree.  I had diet soda with it for a short while, then began noticing alarming side effects.  I felt pressure in my head, some wooziness, and was generally out of it.  I stopped the diet shit completely, and it went away.  Later, some friends who worked as tech at General Foods told us that the whole "natural" thing was bullshit.  This stuff was chemicals mixed in a vat.

Who knows whether it causes cancer or not.  The fact is that it's not good for you at all, and its marketing was a lie.  I want no part of it.

Beware of splenda too.

[WindAndConfusion]

Though there are still plenty of studies that indicate it does a lot of bad things.  I was reading something not long ago about aspartame being linked to causing seizures, and it was a pretty convincing study.  Can't remember where I read it, though.

The study I linked to was a systematic review of fifteen years' or so worth of evidence. There are no reputable studies that suggest that aspartame presents more than an almost negligible risk, if any risk at all.

The seizure thing went like this: Aspartame is a dipeptide containing two amino acids, phenylalanine and aspartic acid (aspartate). Aspartate can cross the blood-brain barrier, and it can be converted to a neurotransmitter (N-methyl-D-aspartate, NMDA), and it's absorbed faster than amino acids normally are from proteins, so there was concern that it could spike blood plasma concentrations of aspartate enough to elevate the concentration of NMDA in the synapses of the brain enough to induce a seizure. Sure enough, giving very large doses of aspartate to monkeys with epilepsy induced a few extra seizures as compared to control monkeys (that also had epilepsy, of course). (I may be getting some minor details wrong, but if that's the case then it was because the authors of the study made a methodological mistake.)

Severe seizures lasting more than 10-15 minutes may carry a small risk of brain damage from excitotoxicity. This especially becomes a concern for seizures lasting 20-30 minutes or longer, or for patients in status epilepticus (many seizures over a short period of time, so that the brain cannot fully recover between episodes). I don't think the study actually managed to cause any brain damage, so it was only able to suggest that aspartame might theoretically be an excitotoxin under certain circumstances for certain at-risk patients, but only at extremely high dosages.

[WindAndConfusion]

Who knows whether it causes cancer or not.

It doesn't cause cancer at a statistically detectable rate, as the authors of the study quite convincingly lay out. If it presents any risk at all, it must have been too small for many powerful studies to find it.

[WindAndConfusion]

I already posted about this.  It's not carcinogenic.  It contains the amino acid phenylalanine, which can be harmful if you have phenylketonuria, which is the body's inability to convert phenylalanine to taurine I believe.

Tyrosine. Taurine is the stuff they put in those energy drinks that taste like battery acid smells.

~

5³-1th post!

[WindAndConfusion]

Last of all, a European Commission study on the subject (PDF). (Copyright-free, as a work of a government agency.)

Another study employing a controlled environment, which was also a randomised double-blind placebo-controlled cross-over trial, concluded that aspartame was no more likely than placebo to trigger headaches (Schiffman et al., 1987).  This study consisted of 40 subjects who complained of aspartame-related headaches.  Subjects received aspartame challenges on days three or five at a total dose of 30 mg/kg bw (for a 70 kg person); subjects received placebo on the other days.  While 35% of subjects developed headaches while on aspartame, 45% developed headaches while on placebo.  In addition, no treatment related effects were detected in blood pressure, or plasma concentrations of cortisol, insulin, glucagon, histamine, epinephrine or norepinephrine.  The subjects who had headaches had lower plasma concentrations of norepinephrine and epinephrine just before the development of headache.  This study has been criticised for using tightly controlled experimental conditions which did not mimic normal life (Edmeads, 1988), but Schiffman et al. (1987) argued that the nature of the study and the primary focus of the questions raised by CDC dictated that they use carefully controlled conditions at a hospital setting.

Start of page 11. The section on epilepsy is immediately below that.

[Quemaqua]

I suppose I'd give more credence to studies if they weren't so often overturned by later evidence.  Wish I could find a link to that other thing I read because none of these are really refuting what it purported.  Either way, I suppose I'm really not qualified to have an opinion anyway.  Most of this is Greek to me.  Case in point, I know a lot of really crazy people who are addicted to diet soda, and all of them are certifiably nuts.  As far as I'm concerned, the stuff is the demesne of fucked-up people, and even if it doesn't cause people to go crazy, it draws them like flies.

And we're forgetting the most important thing in all this: that it tastes only marginally better than vomit.

[WindAndConfusion]

I suppose I'd give more credence to studies if they weren't so often overturned by later evidence. 

That happens to perhaps one study in a thousand. The great thing about empirical science is, even if your theory is complete and utter bollocks, so long as you get the method right your data will always be good.

There are only two types of studies that actually get overturned with any regularity. The first is the study that gets reported directly to the media, before being replicated, often before being published, often without peer-review and often without ever being published. The second type is the fake controversy study, in which unobjectionable results are first misrepresented and then heavily criticized by the media - these studies will often be "overturned" several times each before finally becoming accepted by journalists.

[Xessive]

Yep, taurine is the primary ingredient (well, primary attraction) of Red Bull! Actually I think it's the reason they called it "Red Bull."

[Quemaqua]

I'm just saying I rarely trust when there seems to be evidence of something funny with a chemical or something and it's proven to be perfectly safe... because half the time they later discover something they didn't notice which then proves that yes, it actually does do something bad.  It happens to any study when they realize, "Oh, whoops.  All our data was 100% correct, we just didn't realize that this one tiny thing set off a chain reaction somewhere else that actually makes you blow your intestines out your ass."  Human error happens all the time.  People miss things.

[WindAndConfusion]

"Oh, whoops.  All our data was 100% correct, we just didn't realize that this one tiny thing set off a chain reaction somewhere else that actually makes you blow your intestines out your ass."  Human error happens all the time.  People miss things.

There's nothing to miss with a controlled experiment. They treat the human body as a black box, and instead compare two groups of people who are virtually identical except for the experiment variable. Furthermore, they specifically monitor everything from depression and insomnia to digestive complaints and the incidence of colds. Presumably a post-rectal intestinal inversion would be a very serious digestive complaint, and if it occurred in more than a tiny fraction of the population the study would almost certainly have picked it up. Large-scale meta-reviews (like the ones in the studies I posted) are reliably sensitive to symptoms as rare as several cases per million people. They also reference longitudinal studies that have been ongoing for 15-20 years, so any symptoms that are "hiding" must have either an incredibly low incidence or an incredibly long onset time.

[Quemaqua]

Okiedoke.  All hail infallible man, etc.

[poomcgoo]

Beware of splenda too.

Splenda, or sucralose, is also very safe.  It's newer than the others, and was demonized when it came out I remember, but it's been proven safe like the others.

The big scare started when it was found that one of the artificial sweeteners (saccharin (sweet n low) I think) was found to be carcinogenic in rats.  It ended up having to do with the way rats store urine, which differs from humans.  I forget exact details, but that's what caused the tumors, and that's what caused the notion that it was harmful to humans as well.  It's since been disproven.

If you're finding a negative reaction to aspartame or sweeteners like it, you either have PKU or a placebo effect.  It's really that simple.

[Antares]

There's nothing to miss with a controlled experiment. They treat the human body as a black box, and instead compare two groups of people who are virtually identical except for the experiment variable. Furthermore, they specifically monitor everything from depression and insomnia to digestive complaints and the incidence of colds. Presumably a post-rectal intestinal inversion would be a very serious digestive complaint, and if it occurred in more than a tiny fraction of the population the study would almost certainly have picked it up. Large-scale meta-reviews (like the ones in the studies I posted) are reliably sensitive to symptoms as rare as several cases per million people. They also reference longitudinal studies that have been ongoing for 15-20 years, so any symptoms that are "hiding" must have either an incredibly low incidence or an incredibly long onset time.

Wow... talk about a dangerous amount of hubris.


Part of good science is realizing the limitations of the scientific method and being careful not to make wild sweeping generalizations that are obviously outside the scope of studies like this.  I guaranee you'd never see any of the scientists who participated in this study making black and white statements like that.  Even if it has nothing to do with human error, the very nature of a study doing evertything in it's power to isolate everything but one variable by definition excludes many other outside elements simply because the inclusion of which would render the study useless.

How old are you wind?  It seems to me that I remember learing all about the superiority of science in high school, and learned all about its limitations in college.....

[WindAndConfusion]

Part of good science is realizing the limitations of the scientific method and being careful not to make wild sweeping generalizations that are obviously outside the scope of studies like this.  I guaranee you'd never see any of the scientists who participated in this study making black and white statements like that.

I didn't make sweeping statements. I made extremely precise statements about what the rate of incidence of aspartame-induced cancer must be in order to be undetectable to such a large number of controlled studies. Given that the sample populations they looked out included tens of millions of aspartame users and non-users, I feel confident saying that aspartame must cause cancer in only a few cases per million, or less.

[WindAndConfusion]

The big scare started when it was found that one of the artificial sweeteners (saccharin (sweet n low) I think) was found to be carcinogenic in rats.  It ended up having to do with the way rats store urine, which differs from humans.  I forget exact details [...]

Saccharin is the first sweetener they discuss in the results section of the first study I posted.

[Antares]

There's nothing to miss with a controlled experiment.

Sounds pretty sweeping to me.

I'm not taking issue with your stance on aspartame, I happen to agree.  I'm taking issue with your apparent blind faith in the scientific method to get the right answer to every problem all of the time.

[WindAndConfusion]

Then perhaps you should consider context. I'll admit that was probably a misleading phrase, but I followed it by explaining what I meant.

The point of a controlled experiment is that "missing things" doesn't matter. Either people who consume aspartame get more cancers, or they don't. The evidence strongly suggests they don't.

[Quemaqua]

It should again be noted that at no point was I ever talking about cancer.  Just in case somebody missed that.

[WindAndConfusion]

Fine, Que was talking about post-rectal intestinal inversions. The data also support the hypothesis that aspartame users don't have those with a greater frequency than the general public, either.

[Quemaqua]

No, I was talking about seizures.

[WindAndConfusion]

Oh. You're going way back into the thread, then.

The second study I posted (by the EU Scientific Committee on Food) addresses that one in the section on epilepsy, page 11.

[Quemaqua]

Though what I read didn't have anything to do with epilepsy (and I've continued to look but still can't find it -- was in a science journal, not online).  But that's neither here nor there.

[WindAndConfusion]

In practical terms, "epilepsy" just means "an abnormal tendency towards seizures." Anyway, the study I mentioned describes the experiment you seem to be interested in:

The AFSSA (2002) report noted that

Among the possible adverse effects of aspartame, researchers have paid particular attention to seizures. Several studies have suggested a relationship between the consumption of large amounts of aspartame and the triggering of epileptic seizures. In an old study (1972), on new-born monkeys (2-3 animals per group) treated with doses of aspartame of 1, 3 and 4g/kg bw/day for 52 weeks, epileptic seizures were recorded at the highest doses, after 218 days of treatment. Thereafter, sporadic convulsions were observed during handling of the animals. These symptoms were identical with those observed in young monkeys treated with phenylalanine.
In contrast, in a similar study also conducted on young monkeys, no effect was observed at doses of aspartame of 2 and 2.7 g/kg bw/day. The different results observed in the two studies could be explained by differences in the exposure conditions, the food and the state of health of the animals (JECFA, 1980).

I already discussed this in Reply #7.

[Quemaqua]

I dated a woman with epilepsy, so yes, I'm aware of what it is.  And the study that I read about wasn't done on animals, it was done on non-phenylketonurics.

[Xessive]

I dated a woman with epilepsy, so yes, I'm aware of what it is.

Same here. She hadn't had a seizure or any epileptic reactions in years though. Man, I miss her a lot.

[Xessive]

Haha Dr. Cox just said something hilariously relevant on Scrubs tonight

"Why don't you go get me a big cup of coffee with so much damn fake sugar in it the coffee itself gets cancer!"