Some research shows a link between loss of smell or loss of taste and future dementia such as Alzheimers. Also hoarders can be on their way to dementia because it is a mental disorder usually caused by traumatic distress in their lives. My late husband couldn't smell sour food so I had to be careful with freshness of cottage cheese which he covered with loads of French dressing. If I told him it was not fresh he would eat the bad food just to try to prove me wrong. He was able to smell the broken gas line in the yard, however. I think he had hallucinations as well and then was normal at other times. He never was diagnosed because he also slipped through our fingers on his health problems, living in denial until he was paralyzed. He lied about everything to the week before he died, then was unconscious for a week. I hope I am not upsetting anyone, but our long lives depend upon living in reality. There is help out there for everyone. Dorisena