Should we be worried about a future with alzheimers?

This blog is dedicated to the proposition that an active, healthy lifestyle will work wonders for people who are confronting a real risk of developing alzheimers disease. My father died of alzheimers in 2004 but suffered from the debilitating effects of dementia and an unhealthy lifestyle for many years prior to his passing. His father died in 1962, diagnosed at that time with dementia and arteriosclerosis, hardening of the arteries, they told us. Dad's first 60 years of his 81 were rather "normal" or uneventful as far as lifestyle issues are concerned. Except for the fact that his weight ballooned after he quit smoking at about age 37. Grampa died at age 70 and spent his whole life, as far as I can recall, smoking several packs of cigarettes a day and, after retirement, sitting in his easy chair drinking coffee. He spend the last 8 years of his life in a prison-like old folks home not knowing who he was or why he was there. More on their lifestyles later...but WHAT ABOUT ME? I am now 61 and wondering about my health and my future...