Who is doing that?
And what do they eat and drink?
Ok then.
Fluoride in water for example to increase tooth health safely and sufficiently, according to World Health Organization and FDI World Dental Federation. LOL, for "dental health".
But there have been over 34 human studies and 100 animal studies linking fluoride to brain damage,3 including lower IQ in children, and studies have shown that fluoride toxicity can lead to a wide variety of health problems, including: increased lead absorption, disrupts synthesis of collagen, hyperactivity and/or lethargy, muscle disorders, thyroid disease, arthritis, dementia, bone fractures, lowered thyroid function, bone cancer (osteosarcoma), disrupted immune system, damaged sperm and increased infertility.
Our foods have been treated with many types of chemicals so that they will last longer in the fridge, kill any kind of germs and to increase flavor/looks/protein levels. Those chemicals most of the time are labelled on the food pack. The effects are pretty much the same as with fluoride above.
So you also asked what "do they" eat? The people who own the health organizations? People like the pope? People like the queen of england? Well they definitely do not consume the shit you buy from your local store, they get their food shipped to them from clean sources for damn sure, lol.