If that worries you so much, you could treat your body more riskily to even the odds.

I'd be worried about general rough-lifestyle stuff affecting your brain's health as well. It is ultimately also a physical organ. Also, being unhealthy is not pleasant in general for many people.

Another approach might be to just slowly increase enjoyable risky behavior that's more or less all or nothing in its bad effects: driving fast, base jumping, motorcycle riding, helicopter piloting...

Indeed - my mother is entering the advanced stages of the disease, and it started to be quite noticeable in her late 60s. I don't even plan on having retired by then! Both of her parents had the disease, so I figure I have at least a 50% chance, likely greater. The video mentioned that you would need to start treating the amyloid plaques at least a decade before symptoms start. When the kids are a little older, I plan on entering a longer-term study or drug trial well before I have any signs of the disease, there are several currently going on. Regardless of whether I ultimately would acquire it without any treatment, I have a very keen interest in helping further research on the disease. It is not a pretty thing for the individual or their family to go through, in my mom's case it's been nearly a decade of gradual but steady decline, with my dad in his mid-70s as her primary caretaker. In another 10 years, there will be a huge upsurge of baby boomers in a similar situation.

Alzheimer's is the most common form of dementia, and dementia is on the rise. So the chances are that most people reading this, not just you Diederich, have some form of dementia in their future. Your family history of old age doesn't include or exclude you, particularly. So you're not unusual, and you're not alone :)

What can we do in the face of this horrible onslaught? Not much, but great journeys start with small steps. Donate to dementia research charities. Become an Alzheimer's friend, if you have such a thing. Volunteer in a care home, perhaps. Talk about dementia with your friends. Write to your local politician. Read about your government's policies.

Just don't do nothing.

Incidentally, I recommend reading Atul Gawande's Being Mortal. Not necessarily for answers, perhaps as an exhortation that we can handle things better.

If it helps, your own lifespan is quite weakly correlated with that of your parents (no good citation offhand, but I've read it before..here is one source: https://www.sharecare.com/health/longevity/how-parents-lifes...).

Of course, living into your 80s is not at all uncommon today.