Saturday, September 15, 2007

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.

Cellphones: No evidence will ever be enough

Mobile phones do not pose a health risk, according to one of the biggest studies into their dangers. But this is only in the short term; long-term damage cannot be ruled out. Six years of research by 28 teams, at a cost of £8.8 million, have failed to substantiate any of the health claims made about mobile phones or the masts that broadcast their signals.

But the fears could not be entirely laid to rest, said Professor Lawrie Challis, chairman of the Mobile Telecommunications and Health Research programme, which oversaw the study. This was because cancer had a long latency period, and mobile phones had not been in use long enough to rule out risk. A second study, for which 6 million pounds has been earmarked, would follow mobile-users over a long period to see if intensity of use has any link with the frequency of cancers.

Professor Challis said that the results so far were “reassuring” – there was no evidence of immediate or short-term damage and no association between use and cancer. He said that experiments on tissue had produced no effects, and the committee responsible for the programme believes that there is no need for further work in this area.

The researchers tested people who complained that they were hypersensitive to electromag-netic fields and found that they were able to tell whether the fields were turned on or off. Their symptoms must have some other cause, he said.

Professor Challis emphasised that although the mobile phone industry had jointly funded the research with the Government, the committee had been protected from any undue influence. He said that the best researchers had been sought and their work published in peer-reviewed journals. Of the 28 projects funded, 23 were now complete and resulted in 23 published papers. Yesterday’s report summarises the conclusions.

Professor Challis said: “We cannot rule out the possibility that cancer could appear in a few years’ time, both because the epidemiological evidence we have is not strong enough to rule it out and, secondly, because most cancers cannot be detected until ten years after whatever caused them.” The research must continue, he added. “We can’t reassure people about the long-term use.”

The only worrying sign was a “very slight hint” of increased incidences of brain tumours among longer-term users, he said, but this was at the borderline of statistical significance and needed further investigation. Evan Harris, the Liberal Democrats’ science spokesman, said: “This report is good news for the public, phone users and the industry. There is no basis on health grounds for any further tightening of regulations or advice on mobile phone masts or the use of handsets.”

A cohort study involving 200,000 people will take place in Denmark, Sweden, Finland and Britain, in which mobile users will be identified and followed for a prolonged period. Any symptoms they suffer will be recorded and compared with their use of mobile phones, using billing records. A senior doctor whose research contributed to the development of a vaccine against cervical cancer is to be the next chief executive of the Medical Research Council (MRC).

Professor Sir Leszek Borysiewicz, who has a strong background in clinical science, will succeed Professor Colin Blakemore at the end of the month. His appointment may help to allay fears that the Government is pressing a heavy business agenda on the body, which distributes 460 million pounds in public funds to biomedical research. Ministers are pushing the MRC to support more science with commercial applications, in line with a review of funding arrangements by Sir David Cooksey, a venture capitalist.


A modest proposal from Australia: Government-funded health "Trainers" for all

The Fascist writer below recognizes that people mostly ignore "health" messages so "make people behave" is the proposed solution. That people have any right to eat what they want is not recognized. Nor is it recognized that "health" wisdom often goes into reverse.

THE idea that taxpayers should subsidise weight loss programs sparked an outcry this week, but it is the first solid policy proposal we have seen to stem a health problem that is costing Australia billions. It comes on the back of calls for cartoon characters to be banned from food packaging, for a tax to be placed on high sugar breakfast cereals and as some hospitals ban surgery on obese people and smokers. Unlike a weight loss program, none of these proposals does anything to change behaviour. That's why both sides of politics say they are seriously considering the weight loss subsidy.

Sixty per cent of our population is overweight. The problem - in defiance of government advertising campaigns to eat more fruit and vegetables and do more exercise - is, like Australians, only getting bigger.

A study in the Medical Journal of Australia has found these public health messages are being absorbed by the public. But it also found this knowledge does not readily translate into behavioural changes. We know what's good for us - but we won't do it.

Every year our public hospitals treat 500,000 people for preventable illnesses. Every year over 50,000 people die from illnesses caused by their poor lifestyle. It's time we asked whether scarce public health dollars should be spent fixing up health problems that are caused by our own unhealthy habits. We're making the unemployed take some responsibility for the public funding they get by working for the dole. In Aboriginal communities bureaucrats have taken control of welfare payments so they can't be spent on alcohol and drugs. The health system is the next area ripe for the new responsibility agenda.

Why should taxpayers fund repeated heart by-pass operations unless the patient receiving them signs a contract agreeing to give up smoking, do 30 minutes of exercise a day and lose weight? What's the point of the public subsidising diabetes or cholesterol tablets if the patient won't exercise and continues eating fatty foods?

A National Heart Foundation study estimates that seven lifestyle factors - obesity, low fruit and vegetable consumption, tobacco use, alcohol consumption, low physical activity, high cholesterol and high blood pressure - cause 52,738 deaths in Australia every year - 39 per cent of all deaths. If we don't start heeding these public health messages (and it doesn't seem likely we will) that number is bound to get even worse.....

The answers aren't necessarily expensive or difficult. We all know what we've got to do to address these health problems: eat healthier food, eat less food overall, quit smoking, take up regular exercise, and control our alcohol intake. But knowing isn't doing. That's why we need to consider a more interventionist approach to preventive health.

The health fund Australian Health Management, which runs an intensive diet and exercise preventive health program, has found spending $600 a year on a personalised health management program for its chronically ill members saves the fund $1800 a year per person. This health fund has found a much more intensive personalised coaching approach to preventive health does pay off.

Instead of spending millions kitting out our ambulances, hospitals and morgues with beds and stretchers that can cope with the morbidly obese, perhaps we should be spending the money on personal coaches that help the chronically ill reinvent their lifestyles. This health fund shows why a subsidy for weight loss programs is worth a trial. The doctors group proposing the plan wants to keep its costs down to $27 million by restricting it to obese people at risk of a chronic illness . But the extra expense of extending it to all overweight Australians could save us much more than it costs.

Telling people what's good for them hasn't worked. If we want cheaper health insurance and lower taxes, it's time to make people take that 30 minute walk and cut down on their calorie intake.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.


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