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What Are Artificial Sweeteners Really Doing to Our Bodies?

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They're what stimulate your sweet tooth without adding girth to your waistline; they give diet colas and sugar-free snacks a saccharine kick without the consequences. At least that's the idea. But these sweeteners have been the subject of hoaxes and misinformation for years, slowly discrediting their wondrous health claims. Can you really, as Dr. Susan Swithers of Purdue University quips, "have your fake cake and eat it, too?"

First, what exactly are artificial sweeteners?

Artificial sweeteners are technically known as non-caloric artificial sweeteners (NAS). Non-caloric in that they contain just a fraction of the calories a nutritive sweetener like sugar does, and often no calories at all.


Currently, the FDA allows the use of six sweeteners: acesulfame-K, aspartame, advantame (which was approved just this May and is 20,000 times sweeter than sugar), saccharin, sucralose and stevia.

Saccharin and aspartame are the two most widely used, though often in conjunction others as they tend to mask each other's unpleasant aftertastes—Diet Coke and Coke Zero both use a mix of aspartame and acesulfame-K.


A quick primer:

  • Saccharin: found in Sweet & Low, Trident Sugar-Free Gum. Sugar's exclusive reign over sweetness came to an end in 1878 when Constantin Fahlberg, a chemist working at Johns Hopkins University licked his hand after a long day of handling coal tar derivatives (which in hindsight was probably not the best of ideas) and unwittingly discovered Saccharin. It's been commercially available since the late Victorian Era and is still widely used in, well, jeez just about everything that has "Diet" on the label.
  • This artificial sweetener, as it's classified by the FDA, is 300 times sweeter than sucrose (table sugar) but provides zero nutritional energy, though researchers still aren't entirely positive on how that's possible. "Evidence for this comes from the fact that if the shape is modified slightly, say by changing the H on the nitrogen to a methyl, the new molecule no longer tastes sweet," states the Elmhurst College virtual chembook. The molecule's shape could also explain the slight metallic aftertaste that saccharine imparts.
  • Aspartame: found in Coke Zero, Pepsi Max, Orbit Gum. Aspartame first hit the market in the late 80s during a widespread public backlash against saccharin after a series of lab studies potentially linked it to bladder cancer in mice. It's not as potent as saccharin, only 200 times sweeter than sugar, and actually produces 4 kCal of energy per gram. But since the amount required to sweeten a can of soda is so minute, it still qualifies as an NAS. It's also considered the closest match to sucrose in terms of its taste profile.
  • Acesulfame-K: an almost exclusively used as a secondary sweetener and paired with either saccharin or aspartame though you can find it under the brand name Sunett.
  • Advantame: a brand new sweetener that hasn't actually hit market yet.
  • Sucralose: commonly known as Splenda.
  • Stevia: a naturally sweet leaf found in NOW Slender Sticks and until recently, Vitamin Water.

All six sweeteners have passed rigorous FDA safety testing—more than 100 studies were done on each one, covering a broad spectrum of potential diseases and maladies. Yet despite this, artificial sweeteners have long been the subject of health scares.

"Since the 1980s people have had concerns that artificial sweeteners could have negative effects," Swithers explained to Science News. "You couldn't have your fake cake and eat it, too." As always, the fact that the study results often depended largely on who funded them—at times NAS manufacturers or the sugar industry—didn't help the uncertainty.


The good news: They probably don't cause cancer

Saccharin (think: "diet" products) has been banned, nearly banned, reexamined, and reinstated multiple times since its inception. Fun fact: It even cost the head chemist of the Department of Agriculture his his job and his career when he attempted to convince President Theodore Roosevelt to ban the substance in 1908. The president reportedly rebuffed Dr. Wiley's arguments with, "Anyone who says saccharin is injurious to health is an idiot. Dr. Rixey gives it to me every day." And you don't tell Teddy Roosevelt that Teddy Roosevelt is wrong.


But the biggest health scare involving saccharin came in the 70s when a series of lab studies linked the sweetener's ingestion with increased rates of bladder cancer within mice. When this study was first published, the American public just about lost its shit in knee-jerk hysteria—as the American public is wont to do—which resulted in Congress not only mandating further study but also an interim labeling measure that required the packaging of all food containing saccharin to contain the message: "Use of this product may be hazardous to your health."

Further studies confirmed that regular high doses of saccharin do lead to higher rates of bladder cancer in mice. But only in mice. Not people. In light of these findings the FDA removed saccharin from its official list of carcinogens in 2000.


Aspartame (think: Coke Zero) has also been suspected of causing cancer, despite having passed FDA inspection in 1981. In 1996, an NIH study suggested that the rise in brain tumor rates between 1975 and 1992 could have something to do with using aspartame, which began around the same time. But subsequent examinations of available statistics from the NCI revealed that the rising trend of nervous system cancers began two years earlier—and nearly a decade before aspartame hit the market.

What's more, the age group most likely to be affected by this increased cancer risk were those 70 and older, many of whom had limited exposure to the chemical. Overall, the FDA describes aspartame as "one of the most thoroughly tested and studied food additives the agency has ever approved" with a "clear cut" safety record.


The bad news: They're probably causing a bunch of other health issues

But just because they won't kill you outright, consuming these sweeteners may have other unintended and unwanted consequences for your health. A new study published in the September issue of Nature has found that high levels of sucralose (Splenda) adversely affect the microcosm of bacteria in the gut, and could lead to obesity and raise the risk of diabetes—the very things skipping sugar is meant to avoid.


A similar study from Duke University and published in Journal of Toxicology and Environmental Health also found that very high levels of Splenda adversely affected the microbiome of bacteria in rodent guts. And NAS use has been linked to increased metabolic risks in young adults per a 2012 study and even higher rates of obesity, according to a 2008 paper published in the journal Obesity.

That's not to say this is smoking gun evidence against artificial sweeteners. A 2010 study concluded that consuming stevia or aspartame immediately before meals resulted in lowered food consumption compared to those who consumed regular sugar beforehand. And running counter to the 2008 Obesity study, a 2012 report from the New England Journal of Medicine found that kids who drank sugary drinks gained more weight over the 18 month trial than those who drank only NAS beverages.


The scientific literature is crowded with these sorts of contravening studies, some finding NAS to be inert and purely beneficial, others finding links between their consumption and some of humanity's most terrifying diseases. Suffice to say, a lot more research is needed before we can say for certain that artificial sweeteners are as safe as we currently think they are. Maybe just stick with the Mexican Coke (the stuff with cane sugar) for now just in case. [ Science News - Saccharin - ChemHerithage - The Economist - Elmhurst College - Time - NCI - Wiki 1, 2]

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