Thursday, September 20, 2007

The Nutrasweet haters

On my FOOD & HEALTH SKEPTIC blog recently, I made some comments about what I regarded as very poorly substantiated criticisms of aspartame (NutraSweet). I gather together below the original post plus the discussion that ensued

The campaign against Nutrasweet (aspartame)

Coming as I do from a big sugar-producing area (Far North Queensland), I always read carefully the little sachets that one gets with one's coffee in coffee lounges. I make sure that I am putting real sugar in my coffee and not some substitute junk. So I should be in sympathy with the campaign against aspartame, right? Wrong! As far as I can see, the campaign is founded on little more than the usual self-glorifying belief that if something is popular it must be bad.

There is a list here of 13 recent anti-aspartame studies and, unless I have missed something, there is not one study of the type that would be decisive: A double-blind study in humans. There are plenty of in vitro ("test tube") and in vivo (rats and mice) studies but that's about it.

And even some of the studies listed there admit that some of the potentially bad byproducts of aspartame metabolism can be broken down rapidly by other food components or metabolites. So showing that rats on a rat diet cannot handle aspartame well tells us nothing about humans. What is needed are studies of humans on a human diet as it seems probable that the human metabolism CAN safely break down aspartame. One has to look at the bottom line, not intermediate processes in isolation.

Since a double blind study in humans should not pose any great difficulty, I think it is the absence of such a study which is most telling.

The attention-seeking studies have however had an effect. There are now various bans on aspartame, particularly in Europe and the UK. Seeing how crazy such places also are about "obesity", it is strange indeed that something which could help combat obesity is restricted on such flimsy grounds. It reinforces the impression that the attack on obesity is insincere too. It adds to the evidence that the anti-obesity campaign is really an expression of middle-class contempt for the working class, who are indeed fatter on the whole: Good old class-prejudice again. The more things change ....

The amusing thing is that all the food and health rhetoric goes right over the heads of most working class people. They very wisely just don't listen. They just eat what they like and damn the consequences. I do too. But my father was, after all, a lumberjack. Heh!


Aspartame revisited

It looks like I poked a beehive when I criticized the anti-aspartame campaign yesterday. I got several accusatory emails, including one from the chief anti-aspartame evangelist herself, Dr. Betty Martini, D.Hum. I have never heard of a D.Hum before. Maybe you get them out of cornflakes packets. I reproduce below part of my correspondence with the D.Hum one:

I initially reiterated my point about the lack of human double-blind studies. She replied:

Dr. Walton's study was double blind. Who do you work for?

I was rather amused by the implicit suggestion of bad faith so I replied:

I work for BIG PHARMA, of course. No honest person could question your beliefs, could they? You can see more about my evil affiliations here:

With the lack of any sense of humour that one expects of fanatics, she did not apparently detect the sarcasm at all. She replied:

I figured as much. I'm not surprised. If you had read Dr. Walton's report you would have seen the link and the fact that it was double blind. Here is the link.

And what a link it is! She had to go all the way back to 1993 to find something and then it concerned ill-effects among a non-random sample of 13 clinical depressives who were fed doses of aspartame seven times a day in pill form, rather than in food.

Quite aside from the ridiculous "sampling", the fact that they got the stuff in pill form quite vitiates the study. Aspartame is supplied IN FOOD and unless you study it in food, you are pissing into the wind. As I have previously pointed out, the potentially bad metabolites of it have been shown to be susceptible to breaking down by other food components or their metabolites so it is the actual bottom line after that happens that we have to look at, not intermediary processes in isolation. And NOBODY seems to have shown any adverse effects from normal use of aspartame in a double-blind study.

I am sure the anti-aspartame evangelists will be sticking pins into a voodoo doll of me by now.


More amusing correspondence from the Aspartame (Nutrasweet) foes

Further to my post of yesterday, I received or had copied to me the following:

We are not in any way associated with Betty Martini whose rants embarrass us all. She is what one of my colleagues called "a self-appointed general"

There is a list on Yahoo, The Aspartame Victim's Support Group that at all times, for the last 10 years has had 1,000 people who list and share their experiences with aspartame.

I replied:

Testimonials are the stock in trade of the quack. They are of no worth in determining cause. Give me double blind studies.

Then the following was copied to me:

Mary... do you know what he's talking about...

A more sophisticated person replied, also copying to me:

He's saying all you're giving him are 'anecdotal' accounts - not double blind human tests with a large number of subjects made up of a 'control' group and an 'aspartame' group. Walton's was too small by scientific standards.

You get mired down in debating this guy, it could go on forever and you won't win because he is there to prove his predetermined point and to make you look bad. Like Martini, he will out-argue you and drag you down. We don't have to prove anything to this character. Those who believe will survive. Those who don't won't. Don't waste valuable time arguing with him. He isn't worth it.

These are obviously sincere people who have themselves had bad experiences that they attribute to aspartame -- but they are badly lacking in scientific understanding. The fact that some academic researchers will hop onto any bandwagon that will give them publications is a serious disservice to them.

Because of their lack of scientific background, they fail to understand that I am asking only for normal scientific caution and so interpret my comments as evilly motivated in some way. I noted at the beginning that I myself do not use ANY artificial sweeteners that I know of so my personal inclination would be to agree with them. I just ask for a conventional standard of proof before I do so.


The aspartame saga continues

I have received the following article from Dr. Joe Schwarcz, Director, McGill University Office for Science and Society. It originally appeared in The Montreal Gazette

We are up to our ears in scientific publications. Over 9000 peer-reviewed journals bombard us with thousands of new research findings every day. They deal with all aspects of science, ranging from highly theoretical quantum mechanical calculations to studies of what goes into our mouths or comes out of our nose. It's a real challenge for our brain to make sense of this tsunami of information! For most of us, the studies that arouse the greatest interest are the ones that have a potential impact on our daily lives, especially on our health. There's certainly no lack of these. Virtually every day we hear of some study that urges us to eat more of a certain food or avoid another. There are studies that warn us about risks of specific chemicals in our environment and others that offer hope for the treatment of disease. To confuse matters, and people, studies are often at odds with each other!

There are several points to remember in the face of this publication onslaught. Science aims for a consensus opinion arrived at by examining all the available information. Rarely are single studies compelling enough to cause a major shift in thinking. Results that are reproduced by different researchers merit more attention. Negative studies are less likely to be reported than positive ones, leading to "publication bias," and research that is funded by vested interests can raise questions about reliability. Keep in mind also that not all peer-reviewed journals are equally demanding in the quality of papers they accept for publication, and that scientists are not immune to human foibles.

When it comes to health-related issues, the fundamental question raised by any new study is whether it is persuasive enough to change any recommendations that are currently in effect. Recently an Italian study on aspartame, the most widely used artificial sweetener in the world, aroused a great deal of interest. This isn't surprising, given the title of the paper: "Lifespan Exposure to Low Doses of Aspartame Beginning During Prenatal Life Increases Cancer Effects in Rats." If such a common product increases our risk of cancer, changes in recommendations about its use would certainly be warranted. But what does this rat study mean for humans?

The current "Acceptable Daily Intake" (ADI) for aspartame in North America is 50 milligrams per kilogram body weight, while in Europe it is 40 mg/kg. Based on numerous laboratory, animal and human studies, adverse effects below these levels are unlikely. Using the lower European value, the ADI for an average adult weighing sixty kilograms is then 2400 mgs, which is the amount of aspartame found in roughly four liters of diet drink. Average consumption of course is way below this, but unfortunately there are people who drink abusive amounts. Perhaps they will re-evaluate their habit after hearing about what researchers at the European Ramazzini Foundation found.

Dr. Morando Soffritti and colleagues fed pregnant rats aspartame-laced food, and then did the same to their offspring throughout their natural lives. The rats were then autopsied and all signs of cancer recorded. One group of rats was fed aspartame at a dose of 100 mg per kilogram of bodyweight, another group at 20 mg/kg, and a third group, given no aspartame, served as a control.

Soffritti was following up on similar research he had published in 2005 which had concluded that aspartame was a carcinogen. That study was criticized by a group of toxicologists assembled by the European Union as having poor methodology and coming to an unwarranted conclusion. Soffritti was understandably angered by the criticism and undoubtedly vowed to "show them." And apparently he has. The current results do show that animals fed at 100 mg/kg per day developed more tumours than those fed no aspartame. This is the amount of aspartame found in ten liters of diet drink. However, when it comes to the 20 mg/kg dose, the incidence of tumours found was essentially the same as in the rats given no aspartame. Based on these results, Soffritti and colleagues correctly conclude that their study showed aspartame to be a carcinogen, and that the effect is dose related.

What do we make of this? It is surprising that a carcinogenic effect was found, given that a large number of other studies have failed to find a link between aspartame and cancer. But the important finding here is the dose-response relationship. As the dose is decreased, so is the risk of tumour formation. At the equivalent of two liters of diet drink a day, the percent of animals bearing tumours is the same as in the control group. So, are these results convincing enough to alter the Acceptable Daily Intake? Before taking such an action, at the very least, we need to see if the experiment can be reproduced by another lab.

The Ramazzini Foundation study [by Soffritti] comes on the heels of a paper recently published in the Annals of Oncology, in which researchers from Italy and France examined the potential association between the risk of cancer and the consumption of artificial sweeteners. They evaluated the rates of consumption of saccharin, aspartame, and other sweeteners in approximately 7,000 individuals with various types of cancers and compared these with a similar number of people who did not have the disease. No link between artificial sweeteners and cancers of the esophagus, colon, rectum, larynx, breast, ovaries, prostate, kidney or mouth was found. And this was a human, not a rat study. Let's remember also that the amount of aspartame found in a couple of diet drinks and artificially sweetened yogurts is way less than the 20 mg/kg per day dose that was shown to cause no increase in tumours in the Ramazzini study. In any case, there is no reason for anyone to be consuming more artificially sweetened products than these.

For now, there seems to be no reason to change recommendations about consuming moderate amounts of aspartame, but rest assured that it won't be long before some new study comes along that either accuses or exonerates aspartame of some nutritional crime. Many scientists will be ready to evaluate that study and change their views if warranted (myself included). That's the way of science.


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