Aspartame is one of the most feared and maligned food additives in history.
But the European Food Safety Authority has just published research that concludes that consuming the artificial sweetener, which has been used extensively for more than three decades, is perfectly safe for the vast majority of people. The EFSA said that the acceptable daily limit for aspartame is 40 milligrams per kilogram of body weight. Considering that a can of Diet Coke contains about 180 mg of aspartame, and the average adult weighs about 70 kilograms (or 154 pounds), a quick mathematical calculation will reveal that you can drink about 16 cans per day without worry.
Moreover, the EFSA said that aspartame becomes toxic only once you consume 4,000 mg/kg of body weight – or about 1,600 cans of Diet Coke a day.
(The exception is people suffering from a rare medical condition phenylketonuria, or PKU, who must strictly adhere to a diet low in phenylalanine, one of the constituents of aspartame. They should avoid the artificial sweetener altogether.)
This is not to suggest you should guzzle diet drinks at an obscene rate.
But the report provides a welcome reminder that calorie-free diet pop is preferable to sugar-laden regular pop, although that is a bit of a false equation because, truth be told, water is better still, as every dietician (and probably your Mom) will tell you.
Yet, the reality is that many people opt for flavoured and fizzy drinks for a variety of reasons – chief among them taste and habit.
At a time of the year when many people make weight-loss resolutions, it is worth remembering that one of the most effective ways to remove calories from a diet is to eschew sugary drinks. Replace four cans of Pepsi with four cans of diet Pepsi, for example, and you drop 600 calories.
Calories aside, excessive consumption of sugar causes far more health problems than aspartame.
So where does aspartame's bad reputation come from?
Largely from a lack of understanding (and sometimes wilful misrepresentation) of chemistry.
First and foremost, there is the naturalistic fallacy, the common belief that what is "natural" is inherently good, and that anything man-made is inherently bad. Practically, that leads us to think that "natural" substances like sugar are always better than "chemicals" like aspartame.
We tend to forget that all foodstuffs have chemical components, whether they are fruits or artificial sweeteners.
Aspartame, which can also be identified as E951 on food labels, has three constituent parts: phenylalanine, methanol and aspartic acid. Aside from sounding unappetizing, they can all be toxic at high doses.
This has led some so-called natural health practitioners such as Dr. Joseph Mercola, the high priest of quackery, to describe aspartame as "by far the most dangerous substance added to most food today." According to Dr. Mercola and his ilk, the food additive causes a dizzying array of health problems, including brain tumours, epilepsy, Alzheimer's disease and birth defects, none of which is demonstrated in credible research.
Anti-aspartame crusaders point principally to methanol, which is essentially wood alcohol – both poisonous and a carcinogen at high doses. But dosage is what really matters. Aspartame contains tiny amounts of these chemicals, as do many other foods. In fact, there is more "poisonous" methanol in a banana than in a can of Diet Coke, and neither will do any real harm, in the short or long-term.
The scare-mongering about aspartame has no real scientific basis. The overheated rhetoric serves first and foremost as a means of flogging "alternative" products.
If anything, misplaced concerns about toxicity distracts from much more real and practical problems.
For, while aspartame is not toxic, there is no question it can mess with your head.
Research has shown that drinking diet pop can actually increase the likelihood a person will overeat and gain weight, and can increase your risk of developing diabetes.
How can that be if these drinks contain no calories?
The principal problem is that people who opt for diet drinks (and other low-calorie foods that contain aspartame such as yogurt, sweeteners, flavoured water and gum) often engage in what scientists describe as "cognitive distortion" – meaning that they compensate for calorie-free foods by splurging elsewhere. The classic example of this what researchers call the Big Mac and Diet Coke phenomenon.
Sweeteners like aspartame – which is about 200 times sweeter than sugar – can also confuse the body's responses. When you consume sweets, the body expects calories to follow; but sweeteners don't deliver the payoff.
That can actually lead to people seeking out more sweets. Many big diet-drink consumers describe themselves as having an insatiable sweet tooth and that is borne out in observational studies.
So, what are we to take from all this?
Basically, that aspartame is not a dangerous chemical. But nor is it a panacea for what ails our sugar-obsessed society.
Follow me on Twitter: @picardonhealth
André Picard