"It [dementia] causes a gradual deterioration of not only the mind but the body as well," Mitchell said. "The body gets weaker and weaker. Just like in cancer or AIDS, for example, people may ultimately have a pneumonia at the end."

I think this is often true based on the passing of my dad.  Ultimately, he stopped eating and then his body stopped functioning.  We were lucky to have hospice care available, but until hospice stepped into the picture, the medical system kept wanting to "fix" my dad even though he was clearly ready to pass on and let go of this life.

His death certificate listed "Failure to Thrive" and "CAD" as his cause of death.  While advanced heart disease was an issue, truly, he forgot to eat, his body forgot how to live.  That is failure to thrive, but really, that's demetia.