The FDA Side Effects of Aspartame

A simple Internet search for aspartame turns up many wild theories about the dangers of this common non-nutritive sweetener. It is everywhere: in soda, gelatins and chewing gum. While there are claims that it causes side effects and disease, including cancer, lupus and multiple sclerosis, research studies do not support the accusations. The FDA declares it safe, as aspartame studies prove time and again that it is.

A laboratory technician reviews samples of aspartame.
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Side Effects Study

In 1983, FDA, approved aspartame as a non-nutritive sweetener. The following year there was an outbreak of side effects that some thought were from use of the additive. Symptoms included headaches, dizziness, mood changes, gastrointestinal symptoms, loss of menstrual period, skin symptoms and other random symptoms, according to the Center for Disease Control, or CDC. When these side effects were reported to the FDA, it asked the CDC to conduct a full scale study into the outbreak. The CDC determined that these symptoms may indicate individual sensitivities, but there was no evidence of the existence of serious, widespread, adverse health consequences resulting from the use of aspartame. As of 2011, all evidence indicates that aspartame is safe for consumption in normal amounts.


One of the most common myths about aspartame is that it causes cancer, mostly brain tumors. However, researchers disagree, including the FDA. The FDA has found no link between aspartame and cancer based on five large studies that have shown negative results, according to the American Cancer Society. The studies linking brain tumors to aspartame were found flawed as the tumors started well before aspartame was approved as a food additive. The American Cancer Society states there are no health risks to aspartame.


Aspartame does present a possible health risk to those with the rare genetic disorder phenylketonuria, which occurs in 1 in 15,000 births in this country, according to the University of Maryland Extension. When aspartame is broken down by the body, it releases phenylalanine. Those who have this disorder are unable to process this chemical, and it builds up in their bodies. Phenylalanine is not dangerous to a healthy person without this genetic mutation. Your body can process it like any other nutrient if you do not have phenylketonuria. This genetic disease is usually detected at birth.

Consumption Levels

The FDA has determined an upper limit for aspartame daily intake. This is called Acceptable Daily Intake, or ADI, and it is 50 mg per kilogram of body weight, according to the University of Maryland Extension. You can get your weight in kilograms by dividing your weight by 2.2. An average adult would have to drink 20 cans of diet soda a day to reach this mark or use 97 packets of sugar substitute. Even then, if you go over the ADI, there is still a safety threshold because the FDA sets the safety limit conservatively. You would have to consume much more to approach dangerous levels, and those higher levels still do not indicate side effects.

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