We’ve all heard that too much sugar isn’t good for us.

That’s one reason sugar substitutes like aspartame have become so popular. But when it comes to aspartame, many people — and science — wonder whether the replacement is actually any better.

If you’ve noticed aspartame showing up in more of your favorite sugar-free foods and drinks, here’s what you should know before deciding whether it deserves a place in your own diet.

What is aspartame? 

It’s popular in diet sodas, zero-calorie sports drinks, low-calorie desserts, and even sugar-free gum, but what exactly is aspartame?

Aspartame was accidentally discovered in 1965 by James M. Schlatter, as he worked to develop anti-ulcer medication. Since then, its popularity has grown.

Today, it is often added to sugar-free options by brands to compensate for taste and can be purchased under the brand names of NutraSweet, Equal, and Sugar Twin. Aspartame is around 200 times sweeter than table sugar.

“Aspartame is found in over 6,000 products,” said Danielle Hendrix, registered dietitian at Health Loft in Tucson, Arizona. “Many chewable or flavored medications and supplements may have aspartame added to compensate for the medication’s bitter taste.”

Is aspartame bad for you?

Hendrix said that, in moderation, aspartame can be a safe alternative for those wanting a low-glycemic sugar option, especially since it doesn’t spike blood sugar and can be helpful for consumers trying to manage their type 2 diabetes.

But those with certain health conditions should be mindful of phenylalanine.

“For individuals with phenylketonuria (PKU), a rare genetic disorder, aspartame is dangerous for consumption as these individuals cannot properly metabolize phenylalanine,” said Hendrix. “Thankfully, any product containing aspartame is legally required to carry a warning label to protect this group.”

What science says

The U.S. Food and Drug Administration has identified that aspartame is safe for consumption at acceptable daily limits. While the World Health Organization has previously classified aspartame as “possibly carcinogenic to humans,” evidence to support that classification is limited.

“The Joint FAO/WHO Expert Committee on Food Additives reviewed the same data and confirmed that aspartame is safe for consumption within the established daily limits,” Hendrix explained. “Acceptable Daily Intake (ADI) of aspartame is 40-50 mg per kilogram of body weight. To put this into perspective, an average adult would need to consume 9-14 cans of diet soda every single day to exceed acceptable limits.”

But additional research has linked long-term and heavy consumption of aspartame to metabolic syndrome, insulin resistance, and negative changes to gut bacteria. Hendrix said you can use alternative options like stevia, monk fruit, and allulose instead of aspartame.

As with most nutrition choices, the key is focusing on an overall balanced diet rather than relying too heavily on any one ingredient.