Aspartame is a low-calorie sweetener used in foods and beverages in more than 90 countries around the world. It is about 200 times sweeter than sugar. The calories in foods can be substantially reduced, and in many products be almost eliminated, by using aspartame in place of sugar. It enhances citrus and other fruit flavors, saves calories and does not contribute to tooth decay.

Aspartame was approved by the U.S. Food and Drug Administration (FDA) in 1981 for use in powdered mixes and as a tabletop sweetener. In 1996, it was approved for use in all foods and beverages, including products such as syrups, salad dressings and certain snack foods where prior approval had not yet been obtained. Prior to its approval, aspartame underwent one of the most thorough scientific reviews ever conducted. Regulators consider it one of the most widely tested ingredients in the food supply. The safety of aspartame has been affirmed by the FDA and leading independent health groups such as the American Medical Association.

The rapid growth and widespread use of aspartame in foods has led to much publicity, and with it, a variety of questions about this ingredient. Here are some of the most frequently asked questions about aspartame.

What is aspartame made of?
Aspartame is made by joining two protein components, aspartic acid and phenylalanine, and a small amount of methanol. Aspartic acid and phenylalanine are building blocks of protein and are found naturally in all protein-containing foods, including meats, grains and dairy products. Methanol is found naturally in the body and in many foods such as fruit and vegetable juices.

How is aspartame handled by the body?
Aspartame is digested just like any other protein. Upon digestion, aspartame breaks down into its basic components and is absorbed into the blood. Neither aspartame nor its components accumulate in the body over time.

What types of products contain aspartame?
Aspartame is used to sweeten many prepared foods, as a tabletop sweetener, and in simple recipes that do not require lengthy heating.

Can aspartame be used in cooking or baking?
Aspartame's components separate when heated over time, resulting in a loss of sweetness. Therefore, aspartame is not recommended for use in recipes requiring lengthy heating or baking. It may, however, be added at the end of the cooking cycle in some recipes. If a food containing aspartame is inadvertently heated, it would still be safe, but would simply not provide the desired sweetness.

Is aspartame safe?
As a governmental agency charged with safeguarding the American food supply, the FDA has concluded that aspartame is safe for the general public, including diabetics, pregnant and nursing women, and children. Persons with a rare hereditary disease known as phenylketonuria (PKU) must control their phenylalanine intake from all sources, including aspartame. These persons are diagnosed at birth by a blood test performed on all babies. Products sweetened with aspartame carry a statement on the label that they contain phenylalanine.

How much aspartame may people consume?
The FDA uses the concept of an Acceptable Daily Intake (ADI) for many food additives, including aspartame. The ADI represents an intake level that if maintained each day throughout a person's lifetime would be considered very safe. The ADI for aspartame has been set at 50 milligrams per kilogram (mg/kg) of body weight. The most frequent consumers of aspartame among adults are consuming only 4 percent to 7 percent of the ADI. The most frequent consumers of aspartame among children have been found to consume from 4 percent to 16 percent of the ADI.

How was aspartame tested before it was approved for use in foods?
Aspartame is one of the most thoroughly studied ingredients in the food supply. It was tested in more than 100 scientific studies prior to its approval by the FDA in 1981. These tests were conducted in animals and humans, including normal adults and children, lactating women and persons with diabetes, obesity and special genetic conditions. Aspartame was tested in amounts many times higher than individuals could consume in the diet. Today scientists continue to conduct new studies on this sweetener as they do many other ingredients used in the food supply. The FDA also monitors and evaluates all research on this and other food ingredients.

Have other regulatory bodies reviewed aspartame's safety?
Aspartame has been approved for use by more than 90 nations worldwide. It is used widely in major industrialized countries such as the United Kingdom, Germany and Japan. Aspartame has been reviewed and found safe by the Joint Expert Committee on Food Additives (JECFA) of the United Nations Food and Agricultural Organization and World Health Organization. It also has been reviewed and approved for use by the Scientific Committee for Food of the European Community.

Can pregnant women consume aspartame?
A task force of the American Academy of Pediatrics' Committee on Nutrition concluded that aspartame is safe for both the mother and developing baby. Of course, it is important for all pregnant women to consult with their doctors regarding nutritional needs during pregnancy.

Can persons with diabetes consume aspartame?
The American Diabetes Association has stated that aspartame is acceptable as a sugar substitute and can be included in a diabetic meal plan.

Is aspartame safe for people with epilepsy?
The Epilepsy Institute, an organization devoted to people suffering from seizure-related problems, has concluded that aspartame is not related to seizures among epileptic patients.

Is there any relationship between aspartame and cancer or tumor formation?
It is physiologically impossible for aspartame to be a carcinogen. Aspartame is broken down in the gastrointestinal tract to small amounts of common dietary components including the amino acids, aspartic acid and phenylalanine. We consume these same components in much greater amounts in common foods, such as milk, meat, fruits and vegetables. The body handles these amino acids in the same way it handles them from other food sources. Aspartame itself never enters the bloodstream. In addition, tests of abuse doses of aspartame in rats and mice showed no evidence of brain tumors or any kind of tumors.

Do some people have adverse reactions to aspartame?
There is no scientific evidence that aspartame is linked to adverse reactions in people. The FDA has investigated all complaints since 1980, and has stated that there has been a gradual decrease in reports of adverse reactions to aspartame received over time. The trend for reports of adverse reactions to aspartame has declined from the 1985 peak. Individuals who have concerns about possible adverse reactions to aspartame should contact their physicians.

Does aspartame cause allergic reactions?
Studies investigating aspartame as a potential allergen have found no association between aspartame and allergic reactions. In double-blind placebo-controlled studies with people who believed they developed allergic reactions after consuming aspartame, researchers found aspartame was no more likely than placebo to cause allergic reactions.

EFSA assesses new aspartame study and reconfirms its safety PDF