Can artificial sweeteners in diet drinks increase your risk of clogged arteries?

What's actually in it

Artificial sweeteners like aspartame, sucralose, saccharin, and acesulfame potassium are in diet sodas, sugar-free snacks, flavored water, protein shakes, and many "light" or "zero sugar" packaged foods. They replace sugar to cut calories, but they still interact with your body in ways scientists are just beginning to understand.

Most people assume these sweeteners pass through the body without doing anything. That's not quite true.

What the research says

A 2026 study in Eur Heart J found that long-term artificial sweetener exposure increased the risk of atherosclerosis, the condition where fatty plaque builds up inside artery walls and eventually blocks blood flow.

The study showed that sweeteners altered gut bacteria in ways that increased the production of trimethylamine N-oxide (TMAO), a compound known to promote plaque formation. Higher TMAO levels drove more cholesterol deposits into artery walls and triggered inflammation in the blood vessel lining.

The effects appeared after months of regular use, not from an occasional diet soda. People who consumed artificial sweeteners daily showed measurably more arterial plaque than those who drank water or unsweetened beverages.

This doesn't mean sugar is the safer choice. Too much sugar also damages arteries. But swapping one for the other may not protect your heart the way you'd expect. Plain water, sparkling water with fruit, or unsweetened tea are the safest options for daily hydration.