Sugar Substitutes—What’s Safe and What’s Not

Artificial Sweetener

Story at-a-glance

  • Sugar substitutes can be divided into four general categories: artificial sweetener, sugar alcohols, natural sweeteners, and dietary supplements such as Stevia and Lo Han
  • Artificial sweeteners can actually be far worse for you than sugar and fructose, and scientific evidence backs up that conclusion
  • Furthermore, numerous studies show they increase weight gain and worsen insulin sensitivity to a greater degree than sugar
  • Natural sweeteners such as honey and agave may seem like a healthier choice, but not only are they loaded with fructose, many are also highly processed
  • In moderation, some sugar alcohols can be a better choice than highly refined sugar, fructose or artificial sweeteners. Of the various sugar alcohols, xylitol is one of the best. When it is pure, the potential side effects are minimal
  • Three of the best sugar substitutes are all-natural Stevia from the whole plant, Lo Han Guo, and dextrose (pure glucose). Contrary to fructose, glucose can be used directly by every cell in your body and as such is a far safer sugar alternative


This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.

By Dr. Mercola

With all the dire health effects associated with refined sugar and high fructose corn syrup (HFCS), many wonder what, if anything, is actually safe to use to sweeten your foods and beverages.

It's certainly a good question. You do have to be cautious when choosing an alternative, as many sweeteners that are widely regarded as "healthy" are, in reality, anything but. A previous National Geographic article1 set out to compare eight different sugar substitutes, which fall into four general categories:

  • Artificial sweeteners
  • Sugar alcohols
  • Natural sweeteners
  • Dietary supplements

Sadly lacking from their review are any notations about adverse health effects of many of the sugar substitutes tested.

Despite copious scientific evidence of harm, artificial sweeteners, for example, are promoted in the featured article, and by "experts" in general, as safe because they "pass through your body undigested." Needless to say, safety concerns will be front and center in this article.

The Case Against Artificial Sweeteners

Sweetener lesson 101: Avoid artificial sweeteners like the plague. While the mechanisms of harm may differ, they're all harmful in one way or another. This includes aspartame (NutraSweet, Equal), sucralose (Splenda), saccharin (Sweet'N Low), acesulfame potassium, neotame, and others.

Twenty years ago I wasn't sure, but now there's little doubt in my mind  that artificial sweeteners can be far worse for you than sugar and fructose, and there is plenty of scientific evidence to back up that conclusion. In fact, there's enough evidence showing the dangers of consuming artificial sweeteners to fill an entire book -- which is exactly why I wrote Sweet Deception.

Aspartame is perhaps the most dangerous of the bunch. At least it's one of the most widely used and has the most reports of adverse effects. There are also hundreds of scientific studies demonstrating its harmful effects.

This is why it's so frustrating to see big companies like Coca-Cola Company purposely deceive you on this issue, which is exactly what they're currently doing with their "public service" announcement-type ads, in which they "affirm" aspartame's safety and benefits.

Center for Science in the Public Interest's (CSPI) Executive Director Michael F. Jacobson issued the following statement in response to Coca-Cola's new ad:2

"Aspartame has been found to cause cancer3leukemia, lymphoma, and other tumors—in laboratory animals, and it shouldn't be in the food supply. We certainly want Coca-Cola to shift its product mix toward lower- and no-calorie drinks, but aspartame's reputation isn't worth rehabilitating with this propaganda campaign.

The company would be better off phasing out its use of aspartame and accelerating its research into safer, natural sweeteners such as those extracted from the stevia plant."

Don't Fall for Coca-Cola's Deceptive "Public Announcement" Ads

Besides pulling the wool over your eyes with regards to the lack of overall safety of aspartame, I think the FTC would be warranted to sue Coke and the other diet soda manufacturers for fraudulent advertising, seeing how:

  1. There's no scientific evidence showing that the use of diet sodas actually lead to weight loss.
  2. On the contrary, studies have repeatedly shown that artificial sweeteners cause greater weight gain than regular sugar.4 Studies have also repeatedly linked artificial sweeteners with increased hunger. For example, one study published in the journal Physiology & Behavior in 19885 found that intense (no- or low-calorie) sweeteners can produce significant changes in appetite. Of the three sweeteners tested, aspartame produced the most pronounced effects.

  3. Scientific evidence shows that aspartame actually worsens insulin sensitivity to a greater degree than sugar.
  4. This is quite the blow for diabetics who obediently follow the recommendation to switch to diet sodas to manage their condition. Unfortunately, in large part due to misleading and deceptive advertising, many doctors and registered nutritionists are still under the illusion that artificial sweeteners are a safe and effective alternative for their diabetic patients.

Artificial sweeteners also appear to cause many of the same health effects associated with high sugar consumption.  Most recently, a report published in the journal Trends in Endocrinology & Metabolism6 highlighted the fact that diet soda drinkers suffer the same exact health problems as those who opt for regular soda, including excessive weight gain, type 2 diabetes, cardiovascular disease and stroke.7, 8 According to the authors:

"This paper... considers the hypothesis that consuming sweet-tasting but noncaloric or reduced-calorie food and beverages interferes with learned responses that normally contribute to glucose and energy homeostasis. Because of this interference, frequent consumption of high-intensity sweeteners may have the counterintuitive effect of inducing metabolic derangements."

So the very reason anyone would consider using diet instead of sugared sweeteners has no basis in fact. Anyone using them would get the same problems as using regular sugar and expose themselves to the well documented risks of artificial sweeteners.

Be Critical of "All Natural" Sweetener Claims

With artificial sweeteners are out of the picture, let's look at some all-natural sweeteners. Natural sweeteners such as honey and agave may seem like a healthier choice, but not only are they loaded with fructose, many are also highly processed. In that regard, you're not gaining a thing. The health effects will be the same, since it's the fructose that causes the harm.

Agave syrup can even be considered worse than HFCS because it has a higher fructose content than any commercial sweetener, ranging from 70 to 97 percent depending on the brand. HFCS, in comparison, averages 55 percent fructose. What's worse, most agave "nectar" or agave "syrup" is nothing more than a laboratory-generated super-condensed fructose syrup, devoid of virtually all nutrient value.

Honey is also high in fructose, averaging around 53 percent, but contrary to agave it is completely natural in its raw form, and has many health benefits when used in moderation. Keep in mind you're not likely to find high quality raw honey in your local grocery store. Most of the commercial Grade A honey is highly processed and of poor quality. All in all, it's important to realize that regardless of the source (be it HFCS, honey or agave), refined fructose:

  • Tricks your body into gaining weight by fooling your metabolism, as it turns off your body's appetite-control system. Fructose does not appropriately stimulate insulin, which in turn does not suppress ghrelin (the "hunger hormone") and doesn't stimulate leptin (the "satiety hormone"), which together result in your eating more and developing insulin resistance.
  • Activates a key enzyme that causes cells to store fat; this is the so-called "fat switch" revealed in Dr. Richard Johnson's book by the same name.
  • Rapidly leads to weight gain and abdominal obesity ("beer belly"), decreased HDL, increased LDL, elevated triglycerides, elevated blood sugar, and high blood pressure—i.e., classic metabolic syndrome.
  • Is broken down in your liver just like alcohol, and produces many of the side effects of chronic alcohol use, including non-alcoholic fatty liver disease (NAFLD). Interestingly enough, research has shown that soft drinks increase your risk of NAFLD independently of metabolic syndrome9.
  • Over time leads to insulin resistance, which is not only an underlying factor of type 2 diabetes and heart disease, but also many cancers.

What About Sugar Alcohols?

Sugar alcohols can be identified by the commonality of "ol" at the end of their name, such as xylitol glucitol, sorbitol, maltitol, mannitol, glycerol, and lactitol. They're not as sweet as sugar, and they do contain fewer calories, but they're not calorie-free. So don't get confused by the "sugar-free" label on foods containing these sweeteners. As with all foods, you need to carefully read the food labels for calorie and carbohydrate content, regardless of any claims that the food is sugar-free or low-sugar.

One reason that sugar alcohols provide fewer calories than sugar is because they're not completely absorbed into your body. Because of this, eating too many foods containing sugar alcohols can lead to abdominal gas and diarrhea. It's also worth noting that maltitol, a commonly used sugar alcohol, spikes blood sugar almost as much as a starchy new potato. Xylitol, in comparison, does not have a great effect on your blood sugar, so from that perspective may be a better choice.

So, in moderation, some sugar alcohols can be a better choice than highly refined sugar, fructose or artificial sweeteners. Of the various sugar alcohols, xylitol is one of the best. When it is pure, the potential side effects are minimal, and it actually comes with some benefits such as fighting tooth decay. All in all, I would say that xylitol is reasonably safe, and potentially even a mildly beneficial sweetener. (As a side note, xylitol is toxic to dogs and some other animals, so be sure to keep it out of reach of your family pets.)

Three of the Safest Sugar-Alternatives

Two of the best sugar substitutes are from the plant kingdom: Stevia and Luo Han Guo (also spelled Luo Han Kuo). Stevia, a highly sweet herb derived from the leaf of the South American stevia plant, is sold as a supplement. It's completely safe in its natural form and can be used to sweeten most dishes and drinks.

Keep in mind that the same cannot be said for the sugar substitute Truvia, which makes use of only certain active ingredients and not the entire plant. Rebaudioside A is the agent that provides most of the sweet taste of the plant. Usually it's the synergistic effect of all the agents in the plant that provide the overall health effect, which oftentimes includes "built-in protection" against potentially damaging effects, but what the FDA has approved as GRAS (generally recognized as safe) are just a couple of the active ingredients, including rebaudioside A used in Truvia.

In one toxicology review,10 the researchers point out that stevioside compounds and rebaudioside A are metabolized at different rates, making it impossible to assess the risk of rebaudioside A from toxicity assessments of stevioside (which has been used as food and medicine in Japan and South America for decades or longer). Additionally, in a human metabolism study, stevioside and rebaudioside A had different pharmacokinetic results. In layman's terms, that means that your body reacts differently to the two compounds; each compound is metabolized differently and remains in your body for different lengths of time.

Truvia may turn out to be a very good substitute to sugar, but I'd have to see more details before giving it an enthusiastic thumbs-up – for the same reason the FDA uses as the basis for their refusal to consider Stevia GRAS: there's just not enough evidence to prove its safety. Lo Han Kuo is another natural sweetener similar to Stevia, but it's a bit more expensive and harder to find. In China, the Lo Han fruit has been used as a sweetener for centuries, and it's about 200 times sweeter than sugar. It received FDA GRAS status in 2009.

A third alternative is to use pure glucose. You can buy pure glucose (dextrose) for about $5-7 per pound. It is only 70 percent as sweet as sucrose, so you'll end up using a bit more of it for the same amount of sweetness, making it slightly more expensive than regular sugar—but still well worth it for your health as it does not contain any fructose whatsoever. Contrary to fructose, glucose can be used directly by every cell in your body and as such is a far safer sugar alternative.

Consider Dampening Your Sweet-Tooth...

Keep in mind though that if you have insulin issues, high blood pressure, high cholesterol, diabetes, or if you're overweight, you'd be best to avoid all sweeteners, including Stevia, Lo Han and dextrose, since any sweetener can decrease your insulin sensitivity. (Most important of all, remember that this goes for artificial sweeteners too!) If you're having trouble weaning yourself off sweet foods and beverages, try Turbo Tapping. It's a clever use of the Emotional Freedom Techniques (EFT), specifically designed to resolve many aspects of an addiction in a concentrated period of time.

Tell Coke They're a Joke!

Obesity and related metabolic diseases are serious public health problems in the United States, and you are being sorely misled by companies pretending to have a solution that, in reality, only worsen the problem. I strongly urge you to let the Coca-Cola Company know how you feel by telling them to stop their deceptive marketing of soda products. Especially their fake "public announcement" ads for aspartame.

Join me in taking a stand against false advertising and let your voice be heard. If you're on twitter, send a tweet to #CokeCEO to let the Coca-Cola Company know you are not happy with their deceptive advertising. If you're on Facebook, please share your thoughts with them on their Facebook Page. Please also email the Coca-Cola Company to let them know how you feel!

Tell Coke They're a Joke via FacebookTell Coke They're a Joke via Email


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