It is not clear that you’ve actually read these articles, or what has been written in the original article here thoroughly. Dialysis causes chronic inflammation, and so the brazil nuts were used to treat the inflammation caused by dialysis, not as a substitute for dialysis. So those who received brazil nuts in the article were successfully treated as monitored by markers for inflammation. No one is suggesting brazil nuts should replace dialysis, it should complement that treatment as a form of integrative medicine.

The study showing that brazil nuts raise selenium levels in the blood definitely had both positive and negative controls (see figure 1, marked as “selenomethionine” and “placebo” respectively).

The brazil nut-colorectal cancer study contains no placebo/negative control group, so your critique is justified in this study alone.

Concerning the HIV study, selenium supplementation in HIV patients and have made similar observations since then with better statistical analysis (n=913 in 2008 and n=300 in 2015, a concise summary can also be found here).

As stated multiple times, brazil nuts were not tested in some of the diseases referred to in the initial article here, and controlled trials would prove what is being proposed. However the literature in the research field of selenium supplementation is robust, but there is no need to inundate readers for the sake of lauding references. As such please inform your critique.