So while this news may be disheartening, a recent Swedish study presents firm evidence that we already possess the tools to reduce the incidence of Alzheimer's Disease within that population and to delay the onset for those who do develop the disease. A combination of a cardiovascular and a strength fitness program, a healthy diet, and activities which stimulate the mind and maintain social interactions provided protection from Alzheimer's disease onset in this peer reviewed study. While it remains to be seen if these results can be duplicated in a more heterogeneous population such as the U.S., this does appear to be a call for action for the population at risk - which is anyone over the age of 50.
This article from Forbes provides more specifics on the study and the compelling results:
Wishing you the best in health and wellness.