Quote from Harvard medicine magazine:

> findings in models show inflammation, cell death, lung and liver effects, changes in the gut microbiome, and altered lipid and hormone metabolism.

Microplastics aren't anywhere near as well understood as sugar or alcohol. There's a growing body of research associating them with negative health outcones, inluding observing them causing harm on a cell level (i.e. not just correlational studies).

It's definitely not true that there isn't evidence of harm. There's a lot. It's more that this is a new field of research and not yet fully understood.

https://magazine.hms.harvard.edu/articles/microplastics-ever...