Although there is some extrapolation in the article, brazil nuts were proven effective in the direct treatment of dialysis patients and at-risk colorectal cancer subjects. Since the article is on the potential of brazil nuts, it may not be surprising that there is some extrapolation. Especially since brazil nuts are more efficient than supplements at delivering selenium to the bloodstream, the mechanism that allows selenium supplements to treat HIV, improve gut microbe health etc. Regardless, people should definitely see a professional who knows what they are doing.