Is aspartame dangerous? The answer you receive depends upon who you ask. However, do varying answers prove an actual controversy surrounding the safety of aspartame and artificial sweeteners in general? Or could it be that something else is informing the debate between two sides who both believe that the weight of science rests squarely on their side?
Aspartame was discovered by accident in 1965 by James Schlatter as he was working on developing a drug to treat gastric ulcers, called N-L-aaspartyl-L-phenylalanine-l-methyl ester (APM). After spilling some on his hand and licking his finger to help pick up a piece of paper, he realized the intensely sweet flavor of the APM. The drug company G.D. Searle developed the product and was granted a patent which eventually expired in 1992. The stories begin to diverge here. Scientists and governments from all over the world have declared aspartame, which has been heavily investigated and tested, to be generally recognized as safe in the sort of quantities that people would ordinarily use when consuming this sweetener, save for people with phenylketonuria (PKU), a disorder where the body can’t deal with phenylalanine, a component of aspartame which is also found in other common high protein foods. On the other hand, others claim that the FDA only granted its approval because influential government and corporate interests suppressed important evidence of adverse health effects, which cause or mimic such nasties as lupus, chronic fatigue, fibromyalgia, multiple sclerosis, and attention deficit disorder.
What does the evidence say? Again, it depends upon who you ask, and what their standards for evidence are. Documented investigations have revealed a tenuous link to brain cancer in a few animal experiments, but these results do not seem to appear in humans. Another legitimate effect seems to be behavioral, in that people who consume artificially sweetened beverages feel virtuous enough to afterwards overindulge in other high-calorie foods, increasing an overall pattern of obesity. This isn’t the fault of the companies who make artificially sweetened foods, however, and perhaps the best medicine here is to follow the ancient Greek advice to “know thyself.” It’s also worthwhile for consumers of artificial sweeteners to look at their overall diet and consider the role of foods that are considered “non-nutritive” and if there are better choices that could be made that have a better chance of providing the nutrition their bodies need. That’s a choice for each person to make, though, and part of the cost of a free society is dealing with the various things other people do with their freedom.
So, why the attack on aspartame and the people who like it?
One reason is that science has given itself kind of a black eye lately, in regard to public opinion. Studies come out regularly that appear to contradict each other over time. Remember how margarine used to be the healthy alternative to evil, heart-clogging butter, and now natural butter is the winner over trans-fatty margarine. Likewise, smoking was healthy, right up until it wasn’t. It’s not inconceivable for the layman to expect no better from the alt-sweetener industry. Scientists have to be paid by somebody unless they have labs of their own and a lucrative yet unrelated day job to pay for it all, and some of them are going to be paid by the makers of artificial food-like substances. In a perfect world, they’d still do the right thing and report the facts, even if the facts are adverse and it means losing their jobs. But this isn’t a perfect world, and some people who call themselves scientists do their best to whip up controversy if it gives their employers an advantage. Sadly, this makes people more likely to distrust reputable science when they come across it.
Another reason is that, like politics and religion, food and diet are a major part of a person’s identity and those who are heavily invested in a belief may have a lot to lose if they are perceived as being wrong. Ideally, people would change their minds to adapt to new and better data, but humans are funny critters and often find this hard to do. They may lose friends and social support networks in the process. This may not mean as much as it used to when we relied on the same tribe for help, shelter, food, and protection and would have been lost without them, but it is still psychologically and economically important to maintain many of our personal networks, sometimes at the cost of truth.
Finally, as Jonathan Haidt explains in this TED talk, many people view purity as an essential part of their morality. This presentation is about moral psychology and politics but also can be extrapolated to many other parts of life, including why anyone can become righteous over such things as aspartame. Just like we’re wired to be tribal, we’re also apt to fret over what we, and others, eat or put in their bodies. Diet choices can serve as a kind of tribal indicator, because people who eat the same things may identify with your in-group, while people who eat that other, more yucky stuff may seem barely even human. This is true whether the concern is based in science, or on seemingly irrational moral revulsion over consumption of foods that are artificial, not kosher, or foreign.
All of this is to say that if you have decided that aspartame is safe for you to consume, yet your cousin freaks out over your diet soda obsession (or vice versa!), it may take more than presenting scientific studies in order to bridge that moral gap. People are not (usually) robots, and there’s more at play in our squishy grey matter than pure rationality. We are a product of our heritage; there are very real reasons why introducing truth (or your version of truth) to an opponent is unlikely to be immediately convincing. Yet somehow we muddle through, and mostly manage not to hit each other with sticks. That may be a bigger miracle than being able to drink several liters of soda a day with no ill effects.