Science in the &quot;nutrition community&quot; is really not very good (this isn&#x27;t surprising... it&#x27;s hard to control what people eat (even willing study participants), and even harder to blind anyone involved). Nutrition research is almost entirely based on cohort studies, which are certainly valuable in helping our understanding, but are not great at rigorously proving anything. This isn&#x27;t a slight on the field of nutrition research, it&#x27;s just a really hard problem to solve. Much harder than many people tend to think...<p>I think it&#x27;s overstating it a bit so say those things are &quot;well-known&quot;. There are some indications that those things may result in slight increases of risk for certain types of cancer.