You don’t have to. They don’t make claims of their own. They just report on research.
“They just report on research” requires me actually looking through multiple papers and ensuring that
(1) their interpretation of each piece of research is correct
(2) that the research that they have chosen isn’t cherry-picked to fit a particular point of view.
There are going to be huge numbers of research papers on chemo therapy, some will have better research methodologies than others, some may talk about particular forms of cancer and different forms of chemotherapy. “Doing your own research” involves close-reading and expertise. That’s why I prefer sources that I can trust to have that expertise. I don’t know that about nutrition facts, which appears to be the passion project of an MD who is passionate about nutrition, but who doesn’t appear to have a background in oncology.