Sugar Substitutes - Are They Safe?
Cooperative Extension, College of Agriculture & Life Sciences,
The University of Arizona

written by
Scottie Misner
, Ph.D., R.D. Associate Nutrition Specialist

Controversy over the safety of sugar substitutes is anything but sweet. A recent national survey found that over 144 million American adults consume sugar-free products regularly.

Supporters of no-calorie sugar substitutes, like aspartame and saccharin maintain the sweeteners are safe in moderation. Critics, however, question their safety. One of the most vocal critics has been Michael Jacobson, Ph.D., executive director of the Washington-based consumer group, Center for Science in the Public Interest (CSPI). He likens the consumption of sugar substitutes to playing the lottery.

Is there really cause for concern? Here’s a roundup of the controversies surrounding sugar substitutes:

Approved Sweeteners

Acesulfame-K (Sunett)

First approved by the Food and Drug Administration (FDA) in 1988, the sweetener was approved for use in soft drinks. Acesulfame -K is even sweeter when used in combination with Aspartame. You’ll find the combo in Pepsi One, a newer one-calorie drink.

According to Nutrinova, the make of Sunett, cancer experts initially opposed the sweetener based on incomplete data, but when two of the scientists were later presented with more data, they reversed their opinions. One of the experts, Emmanual Farber, M.D., Ph.D., of Jefferson Medical College in Philadelphia, who is “suspicious” of sugar substitutes in general, says, “based on the data so far, acesulfame-K has not been shown to be carcinogenic. It is reasonably safe.”

Aspartame (NutraSweet, Equal, NatraTaste)

Aspartame is found in over 1,500 products in the U.S. Major health groups and agencies in over 90 countries, including the World Health Organization and American Medical Association have said it’s safe. The one exception is for people diagnosed with phenylketonuria (PKU), a rare genetic condition in which the body cannot properly metabolize the amino acid phenylalanine (a component of aspartame). Most experts have dismissed speculation that aspartame might increase the risk of brain tumors.

Although complaints of adverse reactions, such as headaches, allergic reactions, seizures and behavioral changes have been reported, scientific studies have not been able to prove a clear connection to the sweetener. Still, the Centers for Disease Control and Prevention leave open the possibility that small groups of people are especially sensitive to aspartame.

Saccharin (Sweet’N Low, Sugar Twin)

Despite its use in over 100 countries, the safety of this century-old sweetener is fraught with controversy. In the 1970’s, high doses of saccharin were shown to cause bladder cancer in male rats, prompting an attempt to ban the sweetener. The move was thwarted by Congress to appease consumers.

Some experts argue that the doses of saccharin used in the studies were unrealistically high. Moreover, they say, the way the cancer developed is unique to a rat’s urinary system and therefore not even relevant to humans. Opponents contend that despite no proof saccharin causes cancer in humans, population studies show an association between heavy users of artificial sweeteners (mostly saccharin at the time) and bladder cancer, and should not be ignored.

Sucralose (Splenda)

Sucralose is the only non-caloric sweetener made from real sugar. To produce sucralose, scientists alter the structure of the sugar molecule, making it much sweeter than sugar. Yet it doesn’t promote tooth decay nor affect blood sugar levels, so it is suitable for use with people who have diabetes.

In reviewing over 100 studies over 20 years, the FDA concluded sucralose does not pose cancer, reproductive or neurologic risk to humans. Sucralose poses no safety problems because it is made from sugar. Splenda can also be used by people with phenylketonuria. It may be safely used by pregnant women and nursing mothers.
Sucralose is currently being used to sweeten beverages like Diet RC cola, and Diet Veryfine juice products.

Sweeteners on the Sidelines

Alitame (Aclame)

Alitame, made by Pfizer, Inc., has been under review by the FDA for over 10 years. Safety studies so far have not found it to cause cancer.


Banned in 1970 because a saccharin-cyclamate combination caused cancer in mice, the FDA and National Academy of Sciences have since reviewed the evidence and concluded that cyclamate, by itself, does not cause cancer. However, other health concerns have been raised, such as testicular atrophy and high blood pressure. A petition to reapprove its use has been under review by the FDA for 17 years.


Developed by Monsanto, the maker of NutraSweet, this no-calorie sweetener (40 times sweeter than NutraSweet) is under FDA review.


A natural Alternative sweetener, Stevia rebaudiana is an herb that is much sweeter than sugar, yet is calorie-free. Though it hasn’t gone through the FDA approval process for use as a sweetener, it is sold as a dietary supplement. It is available in powered extract or liquid form. Look for it in the herbal section of health food stores. Avoid the alcohol-based forms.

Take on Sugar Subs

No artificial sweetener should play a major role in a healthful diet. Even if all of these sweeteners were given the green light for safety tomorrow, they would still fall short when it comes to good nutrition. Like sugar, sugar substitutes, and many of the foods that contain them contribute little or nothing in the way of nutrients, and also take the place of more nutritious foods in the diet.
Stevia or sucralose seem to have the fewest safety concerns. For most people, aspartame is safe in moderation. Limit yourself to a couple of servings a day.

Acesulfame-K is still an unknown. It may be safest when combined with another sweetener, so less of each can be used. And an occasional packet or two of Sweet n’ Low isn’t likely to be harmful.

Questions of safety aside, can sugar substitutes help you lose weight? Rising obesity rates would suggest not. Though there is some evidence aspartame can be helpful, most experts agree that sugar substitutes in general are neither the cause nor the cure for obesity.

Consider these points when deciding about using sugar substitutes:

  • Read labels; sugar substitutes are now found in hundreds of products.
  • Vary your choices or use products containing more than one sweetener. Because some sweeteners enhance each other’s sweetness, blends often use less of each, reducing your exposure to any one sweetener.
  • Don’t rely on no-calorie sweeteners to make pounds disappear. If you use sugar substitutes to help manage your weight, make them part of a sensible plan that includes healthful eating, exercise and lifestyle changes.

Resources and References

“Sweet Facts”. July, 1998.
International Food Information Council

“Low-Calorie Sweeteners: Adding Reduced-Calorie Delights to a Healthful Diet”.
Food Insight, January/February, 1998.

“Sugar Substitutes: Americans Opt for Sweetness and Lite”.
John Henkel, FDA Administration November/December, 1999.

Use of Nutritive and Nonnutritive Sweeteners, Position of the American Dietetic Association, J Am Diet Assoc, 1998; 98:580-587.

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Document located
May 2001
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