• The non-nutritive sweeteners or so-called zero-calorie sweeteners that are commonly used in the United States include aspartame, saccharin, sucralose, neotame and, the latest, stevia.
• There is no definitive evidence that artificial sweeteners cause cancer according to the National Cancer Institute.
• Artificial sweeteners, precisely because they are sweet, may encourage sugar craving and sugar dependence and may not be that helpful with weight loss.

The American Diabetes Association, National Academy of Sciences and the National Cancer Institute all hold the position that FDA-approved non-nutritive sweeteners may be safely used by consumers.  Using non-nutritive sweeteners does not appear to affect increase blood sugar or lipids and for adults with diabetes it may improve blood sugar levels when foods with sugar, starch, and fat are also reduced. Despite some help improving blood sugar non-nutritive sweeteners may not be as good when it comes to weight control. This may seem paradoxical however a growing number of studies find that the regular use of artificial sweeteners may actually promote weight gain.

Food reward and weight control

The research suggests that artificial sweeteners do not activate the brain’s “food reward” pathways in the same fashion as natural sweeteners. The “food reward pathways” tell our brain after a meal “you are no longer hungry and may stop eating now.” After a meal that contains artificial sweeteners there is only a partial but not complete activation of the food reward response pathways and as a result may lead to increased appetite and may contribute to obesity. In light of these findings some suggest that we need to un-sweeten the world’s diet as the best approach to stem the tide on the obesity epidemic.

Dr. David Ludwig, an obesity and weight-loss specialist at Boston Children’s Hospital has put forth a number of concerns about non-nutritive sweeteners that are enlightening. Many who use artificial sweeteners actually may replace the lost calories through other sources, possibly offsetting any possible weight loss or health benefits. There is also evidence that frequent use of non-nutrive sweeteners may alter taste perception due to overstimulation of sugar receptors. These sweeteners have a hyper-intense degree of sweetness that can range from 200-to-13,00 times more sweet than table sugar (sucrose) and this may limit taste preference in favor of  artificially flavored sweeter foods. Unfortunately, many artificially sweetened foods are those of lesser nutritional value compared to those foods with more complex taste and higher nutritious value. Importantly, non-nutrient sweeteners are believed to have an addictive property -at least based on animal research.

The bottom line: sweet craving for more sweets over nutritious food may be associated with weight gain. Drinking diet soda may not be the best replacement for drinking sugary soda but with moderation artificial sweeteners do offer a rational approach that we endorse. Remember zero calorie sweeteners are marketed as “natural” but just because they are called natural does not necessarily imply safety.

Further information on common non-nutritive sweeteners

• Aspartame (Equal^®, NutraSweet^®) is one of the most common artificial sweeteners. Approved by the FDA in 1981, it is about 200 times sweeter than sugar. Consumption of aspartame-containing beverages raised some concerns about a possible cancer link in 1996 but the National Cancer Institute has not found any connection with the development of lymphoma, leukemia, or brain cancer (Lim U, et al. Cancer Epidemiology, Biomarkers and Prevention 2006; 15(9):1654–1659.). Aspartame contains the amino acid phenylalanine so for people with a rare genetic disorder called phenylketonuria (PKU) must restrict foods containing this essential amino acid and avoid using products with aspartame. About one in every 15,000 infants born in the United States has PKU -a genetic disease in which the body can’t break down phenylalanine due to an inactive form of the liver enzyme called phenylalanine hydroxylase. Aspartame and any product that contains aspartame has the warning label “Phenylketonurics: contains phenylalanine” and must be avoided.
• Acesulfame-K (Sunett^®, Sweet One^®) 200 times sweeter than sugar
• Saccharin (Sweet’N Low^®, Necta Sweet^®) 300 times sweeter than sugar. Saccharin was first made in 1879 and has been the center of several controversies regarding potential toxic effects. The finding of cancer of the urinary bladder in rodents fed high doses led to the FDA’s call to restrict the use of saccharin; however, an intense public response against the restriction led to Congressional repeal of the requirement for a warning label. Saccharin is now widely used, often in combination with other sweeteners and further studies provide more evidence of safety.
• Sucralose (Splenda^®) 600 times sweeter than sugar.
• Neotame (no brand names) at 7,000 to 13,000 times sweeter than sugar it is the most potent non-nutritive sweetener. Neotame is made with the same amino acids as aspartame  (L-aspartic acid and L-phenylalanine) but is metabolized differently and unlike Aspartame is a negligible source of phenylalanine and people with PKU can use neotame safely.
• Stevia comes from a South American herb (Stevia rebaudiana Bertoni) where it has been used for hundreds of years to sweeten foods and treat burns and stomach discomfort. The stevia plant is part of the Asteraceae family, related to the daisy and ragweed. Stevia is about 200 times sweeter than sugar and is marketed as Truvía® a non-nutritive sweetener that contains erythritol -a sugar alcohol.

Sugar alcohols

There is another category of sugar substitutes with less calories than sugar called sugar alcohols (also called polyols). Sugar alcohols however, do not contain ethanol (alcohol) and are considered nutritive sweeteners, providing an average of 2 calories per gram because of their incomplete digestion and absorption (table sugar has 4 calories per gram). Foods labeled “sugar free” may contain sugar alcohols, non-nutritive sweeteners, or both. Among the more common sugar alcohols are: erythritol, xylitol, sorbitol, and maltitol. These compounds provide the sweet taste close to that of table sugar but are only partially digested and absorbed from the intestines and as a result there is a common “GI side-effect”  with some experiencing diarrhea. This laxative-like effect is more common with increased use.  Compared to sugar, sorbitol has an  approximate “sweetness” about 50-70% less and xylitol is about on par.

Cyclamates banned

When traveling abroad you may come into contact with cylamates — the sugar substitute  that has been banned by the FDA ever since 1969. The original studies in the 1960’s suggested that cyclamates (and saccharine) might increase the risk of bladder cancer in rodents. However, in 1982 the Cancer Assessment Committee of the FDA reviewed the scientific evidence and concluded that cyclamates were not cancer causing (carcinogenic). This was again reaffirmed by the National Academy of Sciences in 1985 and yet to this day a food additive petition filed with the FDA has not been acted upon or approved. Cyclamates are 30 times sweeter than table sugar and are now used in more than 100 countries throughout Europe, Canada and Australia.

Learn more:

What are Added Sugars and How Much is Too Much?

The Sweet Truth

The New Nutrition Label

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Shwide-Slavin, C et al., Nonnutritive Sweeteners: Where Are We Today? Diabetes Spectrum May 2012 vol. 25 no. 2 104-110

Popkin BM, Nielsen SJ. The sweetening of the world’s diet. Obes Res. 2003; 11: 1325–1332.