Artificial Sweeteners: How Harmful Are They?

By Steve Edwards, with Denis Faye

This is the question on a lot of people's minds in light of recent studies that link artificial sweeteners to everything from weight gain to Alzheimer's. Fake sugar has been around for a long time but, until recently, has been able to stray from the crosshairs of legal scrutiny. There's always been scuttlebutt surrounding its safety but, for the most part, it's been dismissed as shoddy research and hippie science, which has allowed the sugar substitute industry to nearly triple over the last decade. Let's take a deeper look into the history of artificial sweeteners, the latest scientific warnings, and some realistic alternatives to playing the part of a human lab rat.

What happened to "calories in, calories out?"
As it turns out, calories may not be the be-all-end-all of nutrition when it comes to obesity. It's already well established that it's the types of calories that you eat, not simply the amounts, that matter when it comes to general health or athletic performance. But common diet lore has been that your weight is purely a function of a number assigned to the energy in your food that's deemed a calorie—a simple and convenient wrapping that's allowed the "no cal" industry to flourish.

The latest research strongly hints that maybe everything we eat, not just calories, is responsible for not only our health but our weight. Before we analyze the latest evidence, let's take a brief look at the history of sweeteners and how these odd combinations of chemicals became an integral part of our diets in the first place.

A brief history of fake sugar
In 1879, a Johns Hopkins University researcher accidentally spilled a synthetic chemical on his hand. For some reason, he took a lick, discovered it was sweet, and saccharin was born. Nearly a century later, it was found that it could cause cancer in lab rats. The Food and Drug Administration (FDA) immediately tried to ban it, only to meet with overwhelming opposition from dieters and, surprise, the diet food industry. Congress settled the matter by requiring a warning label on any products containing saccharin. With a veritable wrist slap as a deterrent to disclaim a risk of cancer, the race for the perfect artificial sweetener was officially on.

Despite a slew of lawsuits, weird science, and other anecdotal evidence against it, the artificial sweetener business has chugged along with increasing effectiveness. Since 1987, the number of Americans who consume artificially sweetened products has more than tripled to nearly 200 million. During this same period, obesity rates have risen from 15 percent to over 30 percent. Here's a quick rundown of seven of the major players.

Saccharin (aka Sweet 'N Low). The oldest and most scrutinized chemical sweetener has been under fire pretty much ever since, well, foods could actually be under fire in the mainstream media. In the 1990s, it was discovered that rats and humans were physiologically different, so the mechanism that caused cancer in the rats didn't apply to us. The above-mentioned warning labels were scrapped, but then, in 2003, the National Cancer Institute released another study saying something along the lines of, "Oops, maybe it does cause bladder cancer after all." But, so far, no word on digging up those labels again; however, below you'll see that saccharin may have bigger fish to fry soon if it's going to stay on the market at all.

Stevia (aka Sweet Leaf or Honey Leaf). An herbal sweetener from South America, stevia is the only sweetener on this list that hasn't received FDA approval. In fact, due to studies on rats and hamsters showing that large doses of stevioside, the active ingredient in stevia, caused low sperm counts and abnormally small offspring, you'll probably never see it approved from the FDA or Health Canada, the European Union, or the World Health Organization. The upside is that it's been used by indigenous cultures for thousands of years, some of which don't seem abnormally small. Because it's natural and time-tested, it's become trendy with the whole-foods sect and can be found at most new age markets, sold as a supplement.

Sucralose (aka Splenda). Take sugar and chemically combine it with chlorine, and voilà! You have a product the human body can't process, so it passes right through. Sucralose has been animal tested and FDA approved. However, there are a few researchers who claim sucralose shrinks the thymus gland and enlarges the liver and kidneys. They also point out that this sweetener was discovered in 1976 and, therefore, hasn't been around long enough to show any long-term effects. Time will tell, but this is currently, despite the warnings, the fastest-rising sweetener on the market.

Aspartame (aka NutraSweet and Equal). This synthetic derivative of a combo of aspartic acid (an amino acid) and phenylalanine is a popular favorite for diet soda drinkers. The only people who absolutely shouldn't consume aspartame are people suffering from phenylketonuria because excess levels of phenylalanine in their blood can cause neurological, behavioral, and dermatological problems. Other research indicates that people can be aspartame-sensitive, receiving headaches from consuming it. Also, there are dozens of theories floating around pinning aspartame with brain tumors, chronic fatigue syndrome, Alzheimer's disease, and so on. Although no study has ever proven any of this, whether or not this compound is truly safe remains to be seen. Lately, negative research related to diet soda has been piling up, which is aspartame's monetary wheelhouse.


Acesulfame (aka Sunett). A sumptuous blend of carbon, nitrogen, oxygen, hydrogen, sulphur, and potassium whipped up by the Germans in the 1960s, acesulfame isn't metabolized by the human body. Numerous studies suggest that acesulfame causes tumors in rats and mice, but the FDA has thrown out these studies for various reasons. Regardless, it's hard not to question the safety of this sweetener until more solid positive evidence is presented.


Sugar alcohols (aka isomalt, hydrogenated starch hydrolysates, or anything on an ingredients list ending in "-itol"). Not really sugar or alcohol, these are sugars fused with hydrogen. The body has a hard time digesting this combination—it usually does so in the intestines, meaning fewer calories absorbed per gram than other carbohydrates (usually about one or two). So you still get calories, only fewer. With no major side effects or even anecdotal bad news, this stuff could be a dieter's dream. Unfortunately, it's associated with regular minor problems, mainly intestinal upset. Common side effects of sugar alcohol are gas, bloating, and diarrhea.

D-Tagatose (aka Naturlose). A "natural" sweetener derived from dairy products, tagatose is similar to sugar alcohols in that it does have some caloric impact—1.5 calories per gram to be exact. The reason for this low number is that the enzymes in the intestines can't process the stuff, so most of it passes through undigested. The downsides of this can be bloating, nausea, and other more audible signs of gastric stress.

The entire history of sweeteners has been controversial but, until recently, not much of the evidence against them has struck a chord with the public. Not surprisingly, the only two that have seen anything affect their market share are the oldest, saccharin and sweet leaf. And, oddly enough, the only one of these that's been "permanently" removed from the FDA's approved list is the only natural one, sweet leaf, which incidentally is also the only one not produced chemically by a large corporation (generally synonymous with having the weakest legal team).

Some new studies could be changing the sweetener world as we've known it. While yet to be declared in any definitive way, each successive study has thrown fuel onto the anti-sweetener fire without a bit of evidence that's been able to slow the blaze. Given that most sweeteners on the market (even with FDA approval) haven't been around long enough for definitive long-term studies to be conclusive, that is a pretty strong indictment that we may want to use at least a little caution in regards to how much we consume.

Some sweet science
While stories have been appearing regularly in the news over the last year, one of the most interesting tidbits of information is a hot-off-the-press study that showed that rats on diets containing saccharin gained more weight than rats given sugary food. The study was published in the journal Behavioral Neuroscience and found that the calorie-free artificial sweetener appeared to break the physiological connection between sweet tastes and calories, driving the rats to overeat. This information could be damaging to the entire industry because the link may have more to do with the calorie-free stimulus of artificial sweetener, which means it could be an effect associated with any of the artificial sweeteners on the market. Furthermore, it enhances the credibility of a large-scale study that linked diet soda drinking with obesity. We'll get to that in a minute, but let's take a brief look at the rat study.

In the experiment, funded by the National Institutes of Health and Purdue University, nine rats received yogurt sweetened with saccharin and eight rats received yogurt sweetened with glucose (sugar). After receiving their yogurt snack, the animals were given their usual food. At the end of five weeks, rats that had been fed sugar-free yogurt gained an average of 88 grams, compared with 72 grams for rats that ate glucose-sweetened yogurt, a difference of about 20 percent. Rats fed sugar-free yogurt were consuming more calories and had 5 percent more body fat.

Since this required further explanation, more research was done. In another experiment, two groups of rats were fed sugary and artificially sweetened drinks to measure changes in their body temperatures. Body temperatures typically rise after a meal because it takes energy to digest food. This effect, known as thermogenesis, is the desired effect of most "fat burning" supplements.

The rats in the saccharin group experienced a smaller average temperature increase, a sign that regular consumption of artificial sweeteners had blunted their bodies' responses to sweet foods, making it harder for the animals to burn off extra calories. Normally, sweet tastes signal the body that it is about to receive a lot of calories and the digestive system prepares to react. When sweet tastes aren't followed by lots of calories, as in the case of artificial sweeteners, the body becomes conditioned against a strong response. The most interesting irony here is that the study suggests that most "diet" foods will likely counteract the beneficial effects of most "diet" supplements.

This becomes more provocative when we look at the next study, which featured real people. In this one, scientists gathered dietary information on more than 9,500 men and women ages 45 to 64 and tracked their health for nine years to record general health trends as they related to lifestyle.

Overall, a Western dietary pattern, which includes high intakes of refined grains, fried foods, and red meat, was associated with an 18 percent increased risk for metabolic syndrome, while a "prudent" diet dominated by fruits, vegetables, fish, and poultry correlated with neither an increased nor a decreased risk. Metabolic syndrome doubles a person's risk of developing heart disease, diabetes, or stroke, according to Dr. Ramachandran Vasan of Boston University School of Medicine.

While this was nothing to be surprised about, the researchers then stumbled on a more puzzling statistic—that the risk of developing metabolic syndrome was 34 percent higher among those who drank one can of diet soda a day compared with those who drank none.

Lyn M. Steffen, an associate professor of epidemiology at the University of Minnesota and a coauthor of the study, which was posted online in Circulation on January 22, 2008, stated that they weren't sure if the increased risk was due to some kind of chemical in the diet soda, or something about the behavior of diet soda drinkers. Then, in reference to the Purdue study, she was reported by the Los Angeles Times last week as saying that it offered a possible explanation.

Another study published last year cited the effects of soda drinkers versus non-soda drinkers. In this one, approximately 6,000 middle-aged men and women were observed over four years. The results showed that those who drank one or more soft drinks a day had a 31 percent greater risk of becoming obese, a 30 percent increased risk of developing increased waist circumference, a 25 percent increased risk of developing high blood triglycerides as well as high blood sugar, and a 32 percent higher risk of having low high-density lipoprotein or "good" cholesterol levels.

Again, the news was not exactly shocking. Then the researchers analyzed a smaller sample of participants on whom data on regular and diet soft drink consumption was available. Those who drank one or more diet or regular sodas per day had a 50 to 60 percent increased risk for developing metabolic syndrome. Clearly, something is rotten in the state of Denmark or, you know, something like that.

The American Heart Association, which publishes Circulation, made a statement that people should understand that the study in their publication did not prove that diet sodas cause heart disease, and it may still be better to have a diet drink than a full-calorie soda. Regardless of this backpedal, it's not difficult to see that some bad things are happening to people who drink diet soda regularly.

The alternative: sugar
This begs the question: why do we need to take all this fake sugar anyway, especially if it's a risk? The answer is because we like sugar. We like it a lot. We now, as a society, get more nutrients from sugar than anything else. In fact, sugary soda is the single largest source of calories we consume, accounting for around 13 percent of calories consumed worldwide. And excessive sugar in your diet, as you've probably heard, can cause a lot of problems (refer to "Sugar vs. Fat: Which Is Worse?" in Related Articles below).

There's no doubt that sugar, especially a lot of sugar, is something we should avoid if staying healthy is our goal. But at least we understand sugar. We know how it works and, whether we want to or not, we can easily understand how to make it a healthy, or at least an acceptable, part of our diets. The same can't be said for any artificial sweetener on the market. All we know is that they lack calories, and now we're not even sure if that will keep us from getting fat.

So since sugar, in moderation, is fine and artificial sweeteners are, at best, an unknown, rational thought should lead us to choose real sugar when we crave something sweet. Our big problem is that too often we've been conditioned to want things to be too sweet. So here are five ways to limit your sugar consumption because, if you can minimize your sweet tooth, you'll have no reason to gamble with artificial sweeteners at all.

Portion control. Not unlike Rome in its final throes, we have become a society that craves excess. A sign in a Denny's window states, "Remember, an apple a day." It offers a perfect metaphor of our obesity epidemic: an apple surrounded by about 2,000 calories of sugar and fat. Our society has gone crazy for "bigger is better." After dinner, your body is not hungry. You don't need 2,000 extra calories. You don't need 200. If you savor a square of chocolate or a tablespoon of Ben & Jerry's slowly, it will curb your cravings without a noticeable effect on your diet.


Don't snack on artificial sweeteners. Gum is probably the worst snack because it creates a stimulus-response reaction that causes you to crave sweet stuff constantly. Sugary gum is bad for your teeth, but at least it runs out of flavor quickly. Artificially sweetened gum turns you into one of the rats in the above-mentioned experiment. When you feel as though you need something sweet, go ahead and have a little sugar. Then brush your teeth. You'll find this satiates your cravings without putting your body into a constant stimulus-response mode.


Add some fruit to your sugar. Fruit is sweet, healthy, and filling. The problem is that fiber can dull its sweetness enough to keep you from choosing it first. But you can dress up fruit with a very small amount of "real" dessert and make it pretty darn decadent, offering you a nutritious and filling dessert that you can still burn off.


Make sure you have some complex carbs in your diet. This may sound boring, but complex carbs, like whole grains, sweet potatoes, rice, and beans n' stuff, all slowly break down into blood sugar. If your blood sugar is steady, you won't crave sugar. You might still habitually crave it, but that's a lot easier to deal with than a sugar-crash craving, which usually leads to bingeing.

Try the protein powder trick. Most protein powders have a small amount of sugar and a touch of artificial sweetener, and are 90 percent protein. If you can find one you like you might be able to curb your cravings with a high-protein snack (try Whey Protein Powder packed with 18 grams of protein per serving). Chalene Johnson, the creator of Turbo Jam®, uses chocolate protein powder as a base for pudding, and Beachbody Advice Staff Denis Faye sprinkles it on cereal. Get creative and you'll get the added benefit of ensuring you have enough protein in your diet to fully recover from your workouts. And this, in turn, also helps reduce sugar cravings.