Aspartame, one of the most common artificial sweeteners used today, is sold as NutraSweet^® and Equal^®. It is used in many foods and beverages instead of sugar because it is about 200 times sweeter than sugar, has fewer calories than sugar, and it does not cause tooth decay. Aspartame is made up of three chemicals that are all naturally found in foods and can be found in the body.

How Are People Exposed to Aspartame?

People are exposed to aspartame through the foods they eat. Aspartame is commonly used as a tabletop sweetener, as a sweetener in prepared foods and beverages, and in simple recipes that do not require too much heating (since heat breaks down aspartame).

FDA Approval

In 1981, after careful review, the Food and Drug Administration (FDA) approved the use of aspartame. It was then used in many foods, such as cold breakfast cereals, chewing gum, dry drink mixes, instant tea and coffee, gelatins, puddings, fillings, non-dairy toppings, and as a tabletop sweetener. It was approved in 1983 for use in carbonated beverages and carbonated beverage syrups. Today it is found in even more food products.

How Much Aspartame is Safe?

Who Decides Safe Levels?

Two units of the United Nations, the World Health Organization (WHO) and the Food and Agriculture Organization (FAO), through their Joint Expert Committee on Food Additives (JECFA), recommend Acceptable Daily Intake (ADI) levels for many food additives. The ADI is the amount of an additive that, if eaten every day for the rest of a person's life, would be considered safe. In the US, the FDA sets ADI guidelines.

How Much is Safe?

Animal studies in the 1970s found that rats could eat 4 grams of aspartame per kilogram of body weight without showing health problems. To be safe, the JECFA divided this dose by 100, and set the Acceptable Daily Intake of aspartame for humans at 40 milligrams per kilogram of body weight.

The FDA, now has stated that the acceptable daily intake of aspartame for humans is 50 milligrams per kilogram of body weight.

This is equivalent to 3500 milligrams per day for a typical 70-kilogram (about 150 pounds) adult, far more than most adults take in daily. For comparison, a can of diet soft drink contains about 180 milligrams of aspartame . So a typical adult could drink 19 cans of diet soft drink each day before going over the recommended level. A 30-kilogram (66 pounds) child would have to drink more than 8 cans of diet soda daily to reach the ADI for aspartame.

Does Aspartame Cause Cancer?

Soon after aspartame was introduced to the market, its safety was questioned. Its role in cancer risk has been widely debated over the last few decades. Concerns still exist today and studies continue to look at the safety of aspartame and other artificial sweeteners.

As recently as April 2007, the FDA released this statement: "Considering results from the large number of studies on aspartame's safety, including five previously conducted negative chronic carcinogenicity studies, a recently reported large epidemiology study with negative associations between the use of aspartame and the occurrence of tumors, and negative findings from a series of three transgenic mouse assays, FDA finds no reason to alter its previous conclusion that aspartame is safe as a general purpose sweetener in food."

What Do the Experts Say?

Aspartame has been approved for use as a sweetener by the FDA and by the Joint Expert Committee on Food Additives of the United Nations Food and Agricultural Organization, and the World Health Organization. They have concluded that aspartame does not cause cancer or other adverse health effects in the general population. Though research into a possible link between aspartame and cancer continues, no study to date has had results that change this conclusion.

Does Aspartame Cause Any Other Health Problems?

Phenylketonuria (PKU)

People born with a rare genetic disorder called phenylketonuria or PKU cannot break down (metabolize) the amino acid phenylalanine. This amino acid occurs naturally and is found in aspartame. PKU is usually detected in babies by a routine blood test at birth. People with the disorder are placed on a phenylalanine-restricted diet and must avoid aspartame.

Other Complaints

The FDA received hundreds of complaints of various symptoms after aspartame was introduced. The most common symptoms were headache, dizziness, stomach (gastrointestinal) symptoms, and change in mood. Less often, seizures were reported. The symptoms did not follow any particular pattern and most were minor. The Centers for Disease Control and Prevention (CDC) concluded that "although it may be that certain individuals have an unusual sensitivity to the product, these data do not provide evidence for the existence of serious, widespread, adverse health consequences attendant to the use of aspartame."

Claims are still made that aspartame is related to numerous health effects including: Alzheimer disease, birth defects, cancer, diabetes, Gulf War syndrome, attention deficit disorders, lupus, multiple sclerosis, and seizures. However, there is very little scientific evidence to support these claims. Human exposure studies done to date, in which volunteers eat known quantities of aspartame, have not shown any evidence of harm.

Methanol, one of the breakdown products of aspartame, is toxic to humans when large doses are eaten and could possibly cause blindness and even death. However, the amount of methanol produced when aspartame is broken down is minimal and well below the level that is a risk to human health.

What Should I Do If I’ve Been Exposed to Aspartame?

You should be able to see if you have taken in aspartame by reading food and drink labels. If you have eaten food that contains aspartame and you are concerned about the possible health effects that may occur, talk with your health care provider.

If you want to avoid aspartame, check all food labels before you buy or eat food or drink.

What's the Bottom Line?

Research on artificial sweeteners, including aspartame, continues today. Current evidence does not demonstrate any link between aspartame and an increased risk of cancer.

Aspartame has not been linked with other health problems except among people with the genetic disorder, phenylketonuria. People with this disorder should avoid aspartame in their diet.

What Other National Organizations Look at Aspartame?

United States Food and Drug Administration
Internet Address: http://www.fda.gov

Two pages at the FDA site are especially informative: http://www.fda.gov/fdac/features/1999/699_sugar.html and http://www.fda.gov/bbs/topics/ANSWERS/ANS00772.html.

National Cancer Institute
Internet Address: http://www.cancer.gov/
An especially informative page is http://www.cancer.gov/cancertopics/factsheet/AspartameQandA.

National Institutes of Health
Internet Address: http://www.nih.gov
An especially informative page is http://cancernet.nci.nih.gov/clinpdq/risk/Artificial_Sweeteners.html.

References

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Revised: 06/30/2007