Browse evidence-based analysis of health-related claims and assertions
When rats are given sucralose, a sugar substitute, it sticks around in their fat tissue for at least two weeks after they stop taking it—even though it’s no longer showing up in their pee or poop.
Descriptive
When rats eat sucralose every day for 40 days, their intestines turn it into two new substances that scientists didn’t know existed before—this means it’s not just passing through their bodies unchanged like we thought.
Mechanistic
Artificial sweeteners might be bad for your health in the long run, so we should use them carefully, know what we're eating, have stricter rules, and do more studies to figure out how to stay safe.
Artificial sweeteners might mess up the good bacteria in your gut, which could mean your body makes less of a helpful substance that keeps your blood sugar in check.
Some sugar-free sweeteners like saccharin might mess up your gut bacteria and make your intestines leakier, which could lead to problems like higher blood sugar and trouble with insulin.
Correlational
People who drink diet sodas and other artificially sweetened drinks may be more likely to have a stroke, heart disease, or even die sooner — even if they’re not overweight or don’t smoke.
Eating too many sugar-free sweeteners might be linked to health problems like weight gain, heart disease, diabetes, some cancers, bad pregnancy results, and seizures in sensitive people.
This study used special tools like food containers to help pregnant women remember exactly what sweeteners they ate, making the results more reliable than just asking them to guess.
Women who eat or drink a lot of sugar-free sweeteners while pregnant are more likely to get gestational diabetes than those who eat very little of them.
If a pregnant woman drinks a lot of diet sodas or eats foods with artificial sweeteners, she might be more likely to develop gestational diabetes—even if she was normal weight or overweight before getting pregnant.
Pregnant women who drink a lot of diet soda with saccharin or sucralose are more likely to get gestational diabetes than those who don’t, with saccharin showing the strongest link.
If a pregnant woman drinks a lot of diet sodas or eats lots of foods with artificial sweeteners, she might be more likely to get gestational diabetes, even after accounting for things like her weight and diet.
Several official health groups have looked at lots of science studies over and over, and they all agree that artificial sweeteners won’t hurt you if you eat or drink them in normal amounts.
When your body breaks down aspartame (an artificial sweetener), it turns into three things you already get from foods like meat, beans, and fruit—and your body doesn’t store them up over time.
If you swap sugary foods and drinks for ones with artificial sweeteners, your body might burn more calories than you take in, causing you to lose fat and feel healthier in ways that matter for your heart and metabolism.
Causal
When people eat or drink things with low-calorie sweeteners like they normally do, studies show it doesn’t hurt their health.
Scientists test artificial sweeteners on animals using way more than humans would ever eat, then say it’s safe for people by dividing that huge dose by 100—but that doesn’t match how much people actually consume.
Even if you have existing health issues like diabetes, studies show that drinking diet soda or eating foods with artificial sweeteners doesn’t seem to make your health worse.
Just watching what people eat and seeing how healthy they are doesn't prove that the food is causing the health results — you need to test it by changing what people eat on purpose.
People who already have health issues like obesity or diabetes often switch to artificial sweeteners to help manage their condition—so when studies see that sweetener users have worse health, it might not be because the sweeteners caused the problem, but because people with the problem chose the sweeteners.
People who drink diet sodas or use artificial sweeteners often have health problems, but it might not be because the sweeteners cause the problems — maybe people who are already unhealthy are just more likely to use them.
Sugar alcohols give you some calories when you eat them, like regular sugar, but fake sweeteners like stevia or aspartame give you almost no calories at all.
A type of immune cell that calms down inflammation (Tregs) doesn’t help kill the Pneumocystis fungus, but it does stop the lungs from getting too damaged — like a brake on the immune system’s overreaction.
Surprisingly, blocking a signaling molecule called IL-9 helps mice clear the Pneumocystis fungus better — it seems IL-9 normally puts the brakes on a helpful immune response.