There actually is a form of Alzheimer's which is thought by the leading scientists to be a "toxic" form that develops from exposure to toxins. It is the rarest of the three forms they have found so far.
There actually is an identified "Alzheimer gene" called the APOE gene. There are three evolutions of it and, depending on which evolution of the gene you have (2,3,or 4), it may predispose you genetically to the disease.
APOE 4/4 is the most significant combination and makes you 60% more likely to develop it. Only 2% of the population fall into this category. Even people with a 4/3 or 4/2 also have increased risk of the disease genetically wihch is about 25%.
This is the gene which controls fat distribution in the body and how well your body does it. If you have heart disease or high cholesterol in your family, that is the first indication that your body may not be as efficient or as highly evolved as others and you could have a 4 hanging around in your DNA.
Genes are not your destiny and diet is more what will throw the switch even if you are a 4/4. You can get the test if you want it from your doctor or the commercial DNA tests like 23 and Me if you want it. Medicare covers it.
There are definite protocols and diets and supplements available now to prevent or slow it down if you know someone who is starting to have issues or just may be predisposed to it. Dr. Dale Bredesen has written a book called "The End of Alzheimer's" which I highly recommend if you are looking. It's fairly easy to read and straightforward. He also has some talks on youtube which are very informative as well.
Bottom line recommendations from him, very little grains and no sugar or processed food. 4/4 people also should eliminate dairy and any other saturated fat items since their bodies can not process it well. He also recommends intermittent fasting 12-16 hours a day (done overnight so most of those hours you are sleeping) to give your body a chance to move the fat around (up to your brain where it is needed most) and clean the excess up and out (from arteries).
Monounsaturated fats are highly recommended like seafood, nuts and olive oil as well as most vegetables and low sugar fruits like berries. Basically, the Mediterranean Diet without the bread.
Alzheimers is a scary disease but there are preventitive measures and even outside the box treatments which are clinically proven to work now. If it's a disease that affects you or someone in your family, there is hope out there. No magic pill which is why it doesn't grab headlines but definite lifestyle changes and diet can prevent or extend the quality of life. The earlier it's started with prevention, the better off especially for high risk category people.
I am not a doctor but I have really educated myself on this topic over the past several months and want others to know that there are things to try that have worked for those diagnosed with the disease or for those highly susceptible to it.
If you needed someone to point out where to look in dealing with this issue, this post is for you.