I cannot add anything authoritative to this, but I do find this very interesting as I know several people who came out of the Vietnam War who exhibit poor health like this. One in particular was one of the first units in. He now lives literally across from the Air Force Academy and is being treated for Agent Orange exposure. All of these symptoms of Parkinsons, dementia, other neurodegenerative diseases as the article states, stomach, etc, are ravaging him. Really sad. He is really suffering. He is fairly certain it is a result of exposure to Agent Orange during Vietnam.
Seeing it up close and personal makes it a bit more real than a 20 second report on network news.