The point is communication affects biology, perhaps more than biology affects communication.
Language Skills In Your Twenties May Predict Risk Of Dementia Decades Later:
"'A puzzling feature of Alzheimer's disease is how it affects people differently,' said study author Juan C. Troncoso, MD, with Johns Hopkins University in Baltimore. 'One person who has severe plaques and tangles, the telling signs of Alzheimer's disease in their brains, may show no symptoms affecting their memory. Another person with those same types of plaques and tangles in the same areas of the brain might end up with a full-blown case of Alzheimer's disease. We looked at how language ability might affect the onset of symptoms.'"