Are Artificial Sweeteners Actually Bad For You?

There are few foods that have a more controversial reputation than sugar, and you've likely heard sweet treats are bad for your health and should be limited. Instead, a laundry list of better-for-you sugar alternatives promise to deliver the same sweetness without the added carbs and calories. That said, there have been mixed guidelines around the long-term consumption of artificial sweeteners, linking it to increased risk of type 2 diabetes, cardiovascular disease, and even overall mortality in adults.

So what's the real deal when it comes to artificial sweeteners? Does the average person need to be concerned? Artificial sweeteners are generally recognized as safe by the US Food and Drug Administration, so the risk of serious health problems is fairly low, says Stephanie Wells, MS, RD, a registered dietitian and the founder of Thyme to Go Vegan Nutrition Services. In the cancer study, for instance, people would need to consume radical amounts of aspartame to be at risk. A 150-pound person could get away with drinking dozens of cans of diet soda without harm, The New York Times reports.

To learn more about the pros and cons of artificial sweeteners, PS talked with registered dietitians to learn more the health risks, whether they're actually bad for you, and what you really need to do to protect your health.

Stephanie Wells, MS, RD, is a registered dietitian and the founder of Thyme to Go Vegan Nutrition Services.

Jenn Baswick, RD, is a registered dietitian and the founder of The Intuitive Nutritionist.

"Artificial sweeteners are sugar substitutes that are used to provide a sweet taste to foods and beverages with little to no calories," says Jenn Baswick, RD, a registered dietitian and the founder of The Intuitive Nutritionist. "They are typically quite sweet, so a small amount of artificial sweeteners can replace quite a large amount of sugar."

You may be familiar with those little packets of artificial sweetener at restaurants and coffee shops, but these sugar alternatives are more common than you may think. "Artificial sweeteners are often found in diet sodas and foods marketed as having 'no added sugar' or being 'keto friendly,'" Wells says. They are also typically found in baked goods, frosting, pudding, chewing gum, ice cream, yogurt, bottled fruit juice, bread, fat-free salad dressing, and condiments like ketchup, she adds.

Side effects from eating artificial sweeteners aren't common. However, some people may be more sensitive to the ingredient and experience headaches or worsened mood after consuming aspartame, in particular, Wells says. Others report digestive upset like gas, constipation, and bloating after consuming foods with certain artificial sweeteners, but it's inconclusive on whether these side effects are actually caused by the artificial sweeteners themselves, Baswick adds.

Now, when it comes to potential health risks, the findings are preliminary, and a lot more research is needed. Some studies have suggested potential links between certain artificial sweeteners and conditions like metabolic disorders, cancer risk, or altered gut microbiota, Baswick says. Specifically, saccharin and sucralose intake were associated with higher blood-glucose responses and altered gut microbiome function in adults, she explains.

Another study found that high consumption of artificial sweeteners, in general, was associated with an increased risk of cancer. That said, the research did not clearly show a cause-and-effect relationship, Baswick explains. "The overall research base currently lacks conclusive evidence of significant health risks in moderate consumption of artificial sweeteners," she says. And, again, the WHO report is talking about a much higher-than-average intake of aspartame.

There may also be a link between artificial sweeteners and inflammation in the gut, according to a 2021 study. Here, too, more research is needed — but if true, artificial sweeteners could exacerbate symptoms of digestive conditions like Crohn's disease or inflammatory bowel disease, Wells explains.

The bottom line is that more analysis is needed to make any conclusive claims about the impact of artificial sweeteners on long-term health risks. "It's quite difficult to be absolutely certain about nutrition findings in research, and these findings are not necessarily showing cause and effect," Baswick says.

(One consideration: if you're pregnant or have preexisting health conditions like phenylketonuria, you may want to talk to your doctor about which artificial sweeteners are safe for you.)

The main difference between artificial sweeteners and sugar lies in their composition, calorie content, and sweetness level, Baswick explains. "Artificial sweeteners are chemically modified compounds made to be low- or zero-calorie substitutes for sugar that provide sweetness," she explains. In other words, artificial sweeteners are created in labs, while sugar is more naturally found in plants like sugarcane, corn, and beets, Wells says.

It's also crucial to remember that sugar is not evil or inherently bad. "Sugar contains calories and contributes to an individual's total energy intake," Baswick says. "It may seem appealing to many that artificial sweeteners offer a way to reduce calorie intake, but it's important to remember that sugar provides a source of energy and can be part of a balanced diet."

So, is sugar better than artificial sweeteners? It's hard to say. "Small amounts of sugar or artificial sweeteners in an overall well-balanced diet are probably not going to be problematic, but relying too heavily on these ultraprocessed foods may crowd out more nutrient-dense foods known to reduce the risk of chronic diseases," Wells says. In the WHO findings about avoiding artificial sweeteners for weight loss, the agency "clarified that the evidence for their new recommendation is weak, so the true impact of artificial sweeteners on our health remains to be seen."

If you want to keep an eye out for artificial sweeteners in your foods, Baswick and Wells say the following are most common:

There's no clear answer and it's difficult to say with certainty that something is absolutely "bad for you," Baswick says. But we want to be mindful about anything we consume, including artificial sugar. "I would say that food is not something to be feared, sugar is not evil, and it can be consumed as part of a healthy, well-balanced diet," Baswick tells PS.

"Artificial sweeteners can be very helpful for people with a serious sweet tooth who are trying to eat less sugar and for people with active type 2 diabetes looking to manage their blood sugar," Baswick says. "My main takeaway is that small amounts of artificial sweeteners and sugar in the diet are not likely to cause health issues in the context of a balanced diet containing plenty of minimally processed fruits, vegetables, whole grains, nuts, and legumes." That said, if you're concerned about your intake of artificial sweeteners, it's best to talk to your doctor about your individual risk.

Andi Breitowich is a Chicago-based freelance writer and graduate from Emory University and Northwestern University's Medill School of Journalism. Her work has appeared in PS, Women's Health, Cosmopolitan, and elsewhere.

Mirel Zaman is the wellness director at PS. She has nearly 15 years of experience working in the health and wellness space, writing and editing articles about fitness, general health, mental health, relationships and sex, food and nutrition, astrology, spirituality, family and parenting, culture, and news.