Medical Edge Newspaper Column

Is Aspartame Safe To Consume?

November 4, 2007
Dear Mayo Clinic:
What is the truth on aspartame? There has been negative press about aspartame for quite a few years now. Frankly, I don't know what to believe.

Answer:
Aspartame (NutraSweet, Equal) is a popular artificial sweetener and an ingredient often found in diet sodas and other food products. The Food and Drug Administration approved its use in the United States in 1981.

Since its approval, there have been claims that aspartame can cause a variety of illnesses and diseases, including brain tumors, breast cancer, leukemia, lymphoma and lupus. Numerous studies have been done in response to these claims, including research conducted by the National Cancer Institute. There's no good or consistent scientific evidence that aspartame causes these health problems.

Aspartame can be a problem for some people, though. Because it contains the essential amino acid phenylalanine, found in all proteins, aspartame may be a concern if you have a rare birth defect called phenylketonuria (PKU). People who have PKU are missing an enzyme needed to process phenylalanine, which can then build up in the body. For infants and children who have this disorder, consuming phenylalanine is dangerous because excess levels in the blood can lead to serious health issues, including mental retardation.

In a few susceptible people, aspartame may trigger headaches, including migraine headaches with or without aura (temporary flashes of light, shimmering spots, and/or partial loss of vision). Also, it's not clear what effect, if any, aspartame and other artificial sweeteners, such as saccharin, have on a developing fetus. So, if you're pregnant, it is best to avoid them.

Overall, the best approach is to use aspartame and other artificial sweeteners sensibly and in moderate amounts. For example, it's fine to substitute diet soda for regular soda. But, diet soda shouldn't be the only beverage you drink. Keep in mind, too, that replacing sugar with aspartame may make foods lower in calories, but it doesn't make them more nutritious. To help your body run the way it should, make sure your diet contains plenty of healthy foods, such as vegetables, fruits and whole grains, and water.

— Donald Hensrud, M.D., Endocrinology, Mayo Clinic, Rochester, Minn.