Part of the reason there’s not more evidence and it’s hard to prove a causal link is because it’s next to impossible to find enough participants for a control group because of how prevalent microplastics have become in our food and subsequently our bodies. You can’t exactly run peer review observational, experimental and double blind studies on only one half (more like one third, as a causal study would need to induce change from a->b) of the required test groups. t- and p-tests also are much less valuable if the sample size is too small.
Part of the reason there’s not more evidence and it’s hard to prove a causal link is because it’s next to impossible to find enough participants for a control group because of how prevalent microplastics have become in our food and subsequently our bodies. You can’t exactly run peer review observational, experimental and double blind studies on only one half (more like one third, as a causal study would need to induce change from a->b) of the required test groups. t- and p-tests also are much less valuable if the sample size is too small.