This page was reviewed under our medical and editorial policy by
Carolyn Lammersfeld, MBA, MS, RD, CSO, LD, Vice President of Integrative Care Services.
This page was reviewed on January 29, 2022.
Aspartame is one of many non-nutritive sweeteners (meaning it has few calories or nutrients) used for sweetness without sugar’s carbohydrates and calories. Even though aspartame has been popular for as long as it’s been around, questions have remained about whether such a calorie bargain is really good for you. The U.S. Food and Drug Administration (FDA) says most research supports the overall safety of aspartame.
Aspartame is a chemical compound derived from two amino acids, which are the building blocks of proteins. Like other sugar substitutes such as saccharin and sucralose, aspartame has a much more concentrated sweetness than sugar itself, with a negligible amount of calories. For this reason, aspartame is popular among people who want to limit their sugar intake.
It’s used as a sweetener in a variety of other sugar-free or low-carbohydrate foods and drinks, including iced tea, lemonade, coffee creamer, cereal, gelatins, pudding, chewing gum and even some medicines.
Research shows no consistent connection between consuming aspartame and the cause of any kind of cancer. Aspartame is considered safe based on the results of more than 100 studies and has been approved for use by the FDA in the amounts people normally eat or drink it. Aspartame isn’t included in the lists of known or likely carcinogens by the federal or international agencies who compile them, since any concerns have been related to animal studies.
One study conducted in Italy in the early 2000s suggested a connection between high doses of aspartame and lymphoma and leukemia in rats. However, the FDA ultimately decided not to change its guidance on aspartame, citing shortcomings in the research. Public health studies in humans have also served to reinforce the safety of aspartame, and are referenced by the National Cancer Institute (NCI). They note a 2006 study of the diets of 500,000 retirees, which found no connection between increased aspartame and lymphoma, leukemia or brain cancer. The NCI also points to an extensive review of studies conducted in 2013: it yielded no associations between several other types of cancer and aspartame. Still, research into aspartame and its effects continues. It may help to reduce the consumption of sugary drinks, which may help with short-term weight loss, since carrying excess weight is a risk factor for many cancers.
The only group for whom aspartame is considered unsafe to eat or drink is people with a rare hereditary disease known as phenylketonuria (PKU). That’s because aspartame contains phenylalanine, which people with PKU have trouble metabolizing.
The FDA regulates aspartame and other food and drink additives in the United States. Other countries and territories have their own regulatory agencies responsible for making sure aspartame and other substances are safe, such as the European Food Safety Authority (EFSA).
The FDA requires that producers of foods or drinks containing aspartame follow certain guidelines. For example, a product containing aspartame needs to have a warning label about phenylalanine so that people with PKU may avoid it. Another requirement is that baked goods or ready-to-bake mixes not contain more than 0.5 percent of their weight in aspartame.
The FDA also offers recommendations for an acceptable daily intake of aspartame for individual consumers. That limit exceeds what most people would consume on a typical day based on weight. According to the FDA’s recommendations, a person who weighs 150 pounds would have to consume up to 17 cans of a typical diet soda or 92 packets of an aspartame-based table sugar substitute to reach that daily limit. EFSA’s daily intake limit is slightly less than that.
If you regularly consume aspartame and are worried about your health, check with a registered dietitian or your care team for guidance. If you’ve been diagnosed with cancer, it’s a good idea to work with your care team on maintaining a healthy diet.
With respect to cancer and diet, researchers continue to monitor the effects of a wide range of substances, including artificial sweeteners such as aspartame.