Aspartame, Equal, Little Blue Packet, the stuff in diet soda. Whatever name you use, chances are you have an opinion about this sweetener. But, do you really have all the facts? Between teaching nutritional sciences at the University of Toronto and consulting with food and beverage companies on regulatory affairs, I’ve examined just about every study on aspartame. Here are questions I often encounter on aspartame along with the answers I give friends, family, students and others: 

Is aspartame safe to use?

Yes. Aspartame has been approved for use by all major food authorities. This includes the World Health Organization’s Joint Expert Committee on Food Additives (JECFA), the U.S. Food and Drug Administration (FDA), Health Canada, the European Food Safety Authority (EFSA), the Food Standards Australia New Zealand and many others.

In fact, it always makes me sad when this question comes from people who need to control their blood sugar and need to reduce their weight to improve their health. Aspartame does not affect blood sugar and switching to low- or no-calorie food and drinks has been shown to help with weight management.

What is aspartame anyway?
Put simply, aspartame is made of the same building blocks we find in foods we eat every day.
And it is digested the same way we digest foods. The digestion products include two amino acids and a small amount of methanol. Remember that amino acids are the building blocks of all proteins, and are found in protein-containing foods. Methanol also comes from many foods we eat, including fruits and vegetables. Once your digestive system splits apart aspartame, the digestion products are identical to those you obtain when you eat yogurt, chicken breasts, orange juice, tomatoes, green beans etc. So what enters your body, is the same building blocks, whether they come from food or aspartame.

Why is there a warning label about phenylalanine? Is it harmful?
Phenylalanine is one of the amino acids found in aspartame, and in many foods. It is not harmful. The warning is for those individuals with a rare genetic disease that cannot properly metabolize this amino acid, and need to watch their intake. This genetic disease is detected at birth and those individuals receive extensive diet counseling as they must also carefully control protein intakes.

Is methanol a problem?
The small amount you obtain when you consume fruits and vegetables or aspartame-sweetened products is not a problem. In fact, you get less methanol from a serving of aspartame-sweetened soda than you do from a serving of tomato juice.

What studies have been done on the safety of aspartame?
Hundreds. It’s likely that more studies have been done on aspartame than on any other food ingredient. That includes lifetime studies in animals and clinical studies in humans. Each time regulatory authorities, health associations and experts are called on to vet reports of an alleged danger of aspartame, they find them flawed and unreliable. Over and over, the safety of consuming aspartame-containing foods has been reassessed, and confirmed.

Why did the European Food Safety Authority review the safety of aspartame? What did they find? 
There is a great deal of misinformation on aspartame causing public concern. To ensure all points of view were considered, EFSA issued an open public call for all data and comments or concerns on aspartame, and compiled an independent group of experts to carefully review all the information provided.

The panel confirmed the safety of aspartame. The panel specifically stated that aspartame does not cause cancer and does not cause any problems during pregnancy and development.  The panel also assessed how much people are eating, and confirmed that intakes of aspartame are below the Acceptable Daily Intake, even for those people that are the highest users of low-calorie products.  So all consumers can confidently enjoy food and beverage products containing aspartame. 

Do you advocate wider use of aspartame?
I advocate maintaining optimal body weight and, if you are diabetic or pre-diabetic, controlling levels of blood sugar. If beverages and foods with aspartame, or any other approved low-calorie sweetener can help you achieve these goals, then use them without hesitation or concern for their safety. This applies to pregnant women and children as well. Don’t make your dietary choices based on fears of aspartame that are unfounded.

Dr. Bernadene Magnuson

Dr. Bernadene Magnuson is president of BMagnuson Consulting in Mississauga, Canada. She works with the food ingredient, feed, food and beverage industries, including Coca-Cola, to develop global strategies, resolve toxicology issues and facilitate regulatory approvals. She also teaches undergraduate and graduate classes as an Associate Professor in the Dept of Nutritional Sciences in the Faculty of Medicine of the University of Toronto.