Can artificial sweeteners in diet drinks and sugar-free foods harm male fertility?

What's actually in it

Artificial sweeteners like sucralose, aspartame, and acesulfame-K are in diet sodas, sugar-free gum, protein bars, flavored water, and thousands of other products. They're marketed as zero-calorie sugar replacements. But they're not biologically inert. Your body absorbs them, and they interact with cells and proteins throughout the body.

What the research says

A 2026 study in Reprod Toxicol combined network toxicology (a way of mapping how chemicals interact with human biology) with lab experiments to identify how artificial sweeteners affect male fertility. They found a clear target: a protein called FGFR1.

FGFR1 plays a key role in sperm cell development and maturation. When artificial sweeteners bind to and disrupt this protein, it interferes with the normal process of making healthy sperm. The lab experiments confirmed what the computer models predicted: sweetener exposure reduced markers of healthy sperm development in cell cultures.

This doesn't mean one diet soda will make you infertile. But regular, daily consumption of artificial sweeteners over months or years could chip away at sperm quality. For men trying to conceive, cutting back on diet drinks and sugar-free foods is a low-effort precaution that the latest science supports.