Health Claims

When mice and rats eat artificial sweeteners like aspartame and sucralose for a long time, their gut bacteria get out of balance, lose variety, and start acting more inflammatory—which might explain why these sweeteners could make the body more prone to inflammation.

Mechanistic

When rats and mice are given saccharin (an artificial sweetener), sometimes their liver gets more inflamed, sometimes their gut gets less inflamed, and sometimes nothing changes—so the effect depends on how much they get, how long they get it, and what health condition they have.

Descriptive

When rats and mice are given a lot of acesulfame potassium (an artificial sweetener), their guts and livers show more signs of inflammation, but if they get only a little or are in a different setup, no inflammation shows up—suggesting there’s a limit to when it causes problems.

Mechanistic

When rats and mice eat sucralose, a common artificial sweetener, their guts get more inflamed, their intestinal lining gets weaker, and the good and bad bacteria in their intestines change — all of which might cause body-wide inflammation.

Mechanistic

If rodents eat aspartame over a long time, their bodies seem to show more signs of inflammation in the blood, brain, liver, and fat tissue, and some internal alarm systems that trigger inflammation get turned on.

Mechanistic

Some studies say eating aspartame doesn’t mess up your metabolism, but the studies aren’t very strong or many — they just watched people instead of testing them in controlled experiments.

Descriptive

Eating or drinking things with aspartame might raise the amount of methanol in your blood, but we don’t yet know if that’s actually harmful or just a harmless blip.

Correlational

Eating or drinking things with aspartame doesn’t seem to raise or lower blood sugar, insulin, or fat levels in people with diabetes, according to some small studies.

Correlational

When people eat or drink things with aspartame (like diet soda), their blood phenylalanine goes up — and this happens more if they haven’t eaten recently, even if they don’t have the genetic condition PKU.

Correlational

What you eat overall—like veggies, meat, or carbs—is probably what’s really changing your gut bacteria, not the sugar-free sweeteners in your diet.

Causal

The changes in gut bacteria seen in mice fed lots of saccharin happen only when they get way more than humans ever eat, so they don’t really tell us what happens when people use it.

Descriptive

Eating sugar substitutes like Splenda or Sweet'N Low doesn't seem to hurt your health, based on what we know now—even though some mouse studies saw gut changes when they gave way too much.

Correlational

When you eat something with aspartame (a sugar substitute), your body uses the phenylalanine in it to build proteins, either as-is or after turning it into another substance called tyrosine.

Mechanistic

When you eat aspartame, the part called aspartic acid gets broken down in your body and mostly turns into carbon dioxide, which you breathe out.

Mechanistic

When you eat or drink something with aspartame, your body breaks it down into smaller pieces, including methanol (which turns into carbon dioxide), and two amino acids—aspatic acid and phenylalanine—that your body absorbs.

Mechanistic

Using sugar substitutes like stevia or aspartame doesn’t make you more likely to have bad health effects than eating sugar, drinking water, or taking a fake pill—so they’re probably safe if you’re trying to lose weight.

Causal

When you use sugar-free sweeteners instead of sugar, the more sugar you replace, the more weight you tend to lose—this suggests that cutting calories by swapping sugar is why you lose weight.

Mechanistic

If you swallow sugar-free sweeteners in a pill without tasting them, your weight doesn’t change consistently—so it’s not the sweet taste that affects weight, but rather whether you eat fewer calories overall.

Mechanistic

If you drink diet soda instead of water or nothing, it won’t help you lose weight or eat less — but if you swap it for sugary drinks, then it might help.

Descriptive

If you swap sugary foods and drinks for ones with artificial sweeteners, you might lose about 1 kg and eat fewer calories—especially if you cut out a lot of sugar. But this only works if you’re replacing sugar, not just adding sweeteners on top.

Causal

Eating or being exposed to the artificial sweetener Acesulfame Potassium might cause the body to release more inflammatory signals in animals, which could affect the uterus in a way that leads to inflammation.

Correlational

Studies on animals suggest that if they’re given a lot of Acesulfame Potassium over a long time, their uteruses contract more strongly and the proteins that control those contractions change in some way.

Mechanistic

If pregnant women eat or drink more of the artificial sweetener Acesulfame Potassium, they might be more likely to have their baby too early.

Correlational

After your body breaks down artificial sweetener sucralose, it makes two modified versions that stick to fat more easily — and that’s why they might hang around in your fat tissue longer than the original sweetener.

Mechanistic