Weight regulation is not a simple matter of "calories in, calories out". Sugar causes obesity disproportionate to its calories, and (surprisingly) no-calorie sweeteners actually cause weight gain. How can you gain weight from something with no calories? The body learns to associate the taste of a food with how much energy it gives. When sweet taste becomes associated with zero calories: (1) people’s metabolisms slow, (2) they eat more – and since their metabolisms are slowed, they gain more from what they eat.
That’s bad enough, but no-calorie sweeteners – even stevia – may contain other serious health risks. This article cuts through the complacency and hyperbole to give you the facts.
FDA-Approved No-Calorie Sweeteners
The Food and Drug Administration (FDA) has approved six no-calorie sweeteners as food additives – i.e., they are "generally recognized as safe" (GRAS) when usage is limited to the FDA-specified "acceptable daily intake" (ADI). The approved no-calorie sweeteners are:
- Acesulfame Potassium (Sunnett, Sweet One)
- Aspartame (Equal, NutraSweet)
- Saccharine (SugarTwin, Sweet ‘N Low)
- Stevia extracts Rebaudioside A and Stevioside (Truvia, PureVia, SweetLeaf Stevia)
- Sucralose (Splenda)
FDA approval does not mean zero risk; it just means that the risk was deemed acceptably low. However, mistakes can and do happen. For example, DES had FDA approval for decades and was given to millions of pregnant women before it was found to cause birth defects and approval was withdrawn.
The four no-calorie sweeteners in widespread use in the US today are aspartame, saccharine, sucralose, and stevia extracts, so these are the ones I’ll focus on. Some of the information comes from the Natural Health Sherpa, which has a series of well-referenced articles. They have a point of view, but the articles are thoroughly documented so you can check facts and draw your own conclusions. Other sources are referenced throughout.
I’ll start by debunking a myth: It’s not true that artificial sweeteners trigger an insulin response, and cause weight gain for that reason. They do cause weight gain, but for a different reason.
Aspartame is an artificial sweetener – a chemical. A scientist at the pharmaceutical company G.D. Searle discovered it by accident while working on a new ulcer drug. It’s used in many diet sodas, and sold separately under the brand names Equal and NutraSweet. Aspartame breaks down over time and under high temperatures, conditions that can occur during storage. At minimum this causes it to lose sweetness. Some say the breakdown products are toxic, even carcinogenic. One in particular, phenylalanine, is dangerous to people with the rare genetic condition Phenylketonuria (PKU).
One of aspartame’s main ingredients is an excitotoxin, which can cause headaches, dizziness, anxiety, and depression. No one disputes this. Aspartame also may cause more serious problems, notably brain tumors. This is unclear because testing was inadequate, data was hidden and altered, and the FDA approval process was flawed.
Searle first applied for approval of NutraSweet, their aspartame product, in 1973. It was approved for about a week in 1974, but the approval was quickly frozen when problems surfaced. Scientists from the FDA and an FDA-appointed Public Board of Inquiry blocked approval of aspartame for the next seven years. Donald Rumsfeld, a former member of Congress and Gerald Ford’s Chief of Staff, became president of Searle in 1977. The day after Ronald Reagan’s inauguration in January 1981, Searle reapplied for approval of aspartame. In April 1981, Reagan replaced the previous FDA Commissioner with Arthur Hull Hayes, Jr. Hayes set up a panel of five scientists to review the Public Board of Inquiry’s unanimous ruling against aspartame. On May 18, 1981, three of the five scientists wrote a letter stating they could not approve aspartame because the brain tumor data was "worrisome", and data in a key study appeared to have been altered. Hayes responded by adding a toxicologist to the team so the vote became 3-3. The panel lawyer pressured the panel to quickly come to a positive decision, even circulating an approval recommendation, but the scientists against approval would not budge. On July 18, 1981, Hayes overruled the Public Board of Inquiry himself, and approved aspartame for use in dry goods. Two years later, aspartame also was approved for use in carbonated drinks, and the ADI was increased by nearly 50%. Two weeks after that, Hayes resigned under a cloud, accused of accepting gratuities from FDA-regulated companies.
Saccharine, sold under the brand names Sugar Twin and Sweet ‘N Low, was discovered over 100 years ago by a chemist experimenting with coal tar derivatives. It, too, is an artificial sweetener – a chemical never intended for ingestion – and people have been arguing over its safety since it was discovered. Being that it’s made from coal tar combined with chlorine and ammonia, it wouldn’t seem safe on the face of it, and studies have shown that it causes a variety of cancers. Products containing saccharine had to contain a warning label from 1972-2000 because it caused an aggressive bladder cancer in rats. The warning was removed when it was found that rat urine is different from human urine and interacts with saccharine in unique ways, so the bladder cancer might not occur in people. But then again maybe it does. Also, saccharine can cause other types of cancers, as well as allergic reactions.
In 1997, in response to the National Toxicology Program (NTP) plan to delist saccharin as a carcinogen, the Center for Science in the Public Interest issued a report saying: "It would be highly imprudent for the NTP to delist saccharin. Doing so would give the public a false sense of security, remove any incentive for further testing, and result in greater exposure to this probable carcinogen in tens of millions of people, including children (indeed, fetuses). If saccharin is even a weak carcinogen, this unnecessary additive would pose an intolerable risk to the public. Thus, we urge the NTP on the basis of currently available data to conclude that saccharin is ‘reasonably anticipated to be a human carcinogen’ because there is ‘sufficient’ evidence of carcinogenicity in animals (multiple sites in rats and mice) and ‘limited’ or ‘sufficient’ evidence of carcinogenicity in humans (bladder cancer) and not to delist saccharin, at least until a great deal of further research is conducted." But they delisted it anyway.
Stevia was available only as a dietary supplement from 1995 until December 2008, when the FDA finally determined that a highly refined extract of stevia called rebaudioside A is safe for use as a food additive (GRAS). Whole leaf stevia and crude extracts of stevia are still deemed unsafe as additives.
The FDA has approved five sweeteners containing Rebaudioside A. At least two are sweetener blends where Rebaudioside A is not the only ingredient, and may not even be the main ingredient. The Cargill product, called Truvia, is sold by Coca-Cola. It also contains significant amounts of a sugar alcohol called erythritol, and the ever-mysterious "natural flavors". The Merisant subsidiary Whole Earth Sweetener manufactures PureVia for PepsiCo. It also contains dextrose (aka d-glucose, a caloric sweetener), cellulose powder, and "natural flavors".
Shortly after Truvia and PureVia received GRAS approval, Wisdom Natural Brands requested and received GRAS approval for its Sweetleaf Stevia product [PDF], which contains both Rebaudioside A, the sweetest part of stevia, and Stevioside. Stevioside also is sweet, but not as sweet as Rebaudioside A, and can have a bitter aftertaste.
Stevia is viewed as the "good" no-calorie sweetener because it’s derived from a plant and thus "natural". But "natural" is not synonymous with "good for your health". There are plenty of plant-based poisons, plus the label has no legal meaning. Consider this description of a "natural" food from the FDA:
From a food science perspective, it is difficult to define a food product that is ‘natural’ because the food has probably been processed and is no longer the product of the earth. That said, FDA has not developed a definition for use of the term natural or its derivatives. However, the agency has not objected to the use of the term if the food does not contain added color, artificial flavors, or synthetic substances.
By this definition, high-fructose corn syrup is "natural", though it’s too highly processed to be recognizable as corn, and is very bad for your health – essentially because it’s so highly processed. Stevia-based sweeteners are just as highly processed and unrecognizable as the original plant.
Misleading as it is, the "natural" label has major selling power. Truvia was the second best-selling sweetener in 2011, behind sucralose-based Splenda. Now soft drinks with stevia-based sweeteners are becoming available. That doesn’t make them good for you. As with any other no-calorie sweetener, regular use will slow your metabolism and increase your appetite so you’ll tend to gain weight.
Last but not least, don’t use whole leaf stevia or crude extracts of stevia for significant sweetening on a regular basis. Although this is stevia at its most natural, studies show it may be dangerous. The FDA says, "Among these concerns are control of blood sugar and effects on the reproductive, cardiovascular, and renal systems." The plant world contains many natural toxins.
Sucralose is an artificial sweetener – a chemical – discovered accidentally while creating an insecticide. It’s sold under the brand name Splenda. Sucralose is so intensely sweet – 600 times sweeter than sugar – that Splenda is cut with dextrose (aka d-glucose, a sweetener with calories) so it has some bulk. A cup of Splenda has 96 calories; a serving of one packet has 4 calories. Since 4 calories is "less than 5 calories", it meets the FDA’s standard for "no calorie food".
Sucralose is made by replacing two of the sugar molecules with chlorine, a toxin. Some people experience side effects with sucralose, notably severe headaches and worsened migraines.
Some rats given sucralose showed toxicity, but they were huge amounts, way beyond what a person would eat. Moderate amounts over the short-term seem safe, but there have been virtually no long-term studies. In fact, there are relatively few studies of any kind, and that is the main problem with sucralose. It has been insufficiently studied, so we really don’t know whether it’s safe.
Splenda is by far the number one no-calorie sweetener, with a dominating 42.8% market share in 2011.
Artificial Sweeteners Contaminate Drinking Water
Even if you don’t want to use artificial sweeteners, to some extent you don’t have a choice. Certain artificial sweeteners are widespread in our drinking water.
Wastewater has been found to contain acesulfame, saccharin, sucralose, and cyclamates (cyclamates are still legal in Europe). The body can’t break them down, so they go right through you into the toilet. Wastewater treatment methods sometimes can’t break them down, either. The treatment process removes some saccharin and cyclamate, but no acesulfame and very little sucralose (12%). Studies show that both acesulfame and sucralose are widespread contaminants of groundwater and tap water:
"Acesulfame was consistently detected in untreated and treated wastewater (12−46 μg/L), in most surface waters, in 65% of the investigated groundwater samples, and even in several tap water samples (up to 2.6 μg/L) from Switzerland."
"…water samples from 19 United States (U.S.) drinking water treatment plants (DWTPs) serving more than 28 million people were analyzed… Sucralose was found to be present in source water of 15 out of 19 DWTPs (47–2900 ng/L), finished water of 13 out of 17 DWTPs (49–2400 ng/L) and distribution system water of 8 out of the 12 DWTPs (48–2400 ng/L) tested."
You may think someone should tell the EPA that artificial sweeteners are contaminating our lakes, streams, and drinking water. Sadly, the EPA already knows and is delighted. They love that people drink so much diet soda that wastewater concentrations of artificial sweeteners are higher than for prescription medicines, and never break down. This means that artificial sweeteners can serve as "wastewater tracers", allowing scientists to follow the movement of water from sewage treatment plants into the environment. That lets them detect leaks and possible contamination.
There have been no studies on whether artificial sweeteners harm plants or aquatic life. Sucralose is toxic to dogs, however, and makes humans fat, so hopefully it won’t build up too much in tap water. The water filters on the market today do not remove artificial sweeteners.
Thoughts? Comments? I’d love to hear them.