The first study[1] I could find that included analysis of vegan vs non-vegan diets' correlation with blood PFAS levels suggest that vegan diets are negatively correlated with some classes of PFAS (and neutral with the other classes analyzed): "The strongest correlations with food groups, derived from a food frequency questionnaire, were observed between levels of PFOA and water consumption (in case of the total study population, n = 72), and between levels of PFOS as well as PFNA and the consumption of ‘meat and meat products’".

I'm not proposing that a single study is proof, but I'm default-skeptical of dietary claims without strong evidence, especially ones that comport with other aspects of worldview or preference.

[1] https://www.sciencedirect.com/science/article/pii/S143846392...

Plant deFense mechAniSm