I wouldnt worry too much. My grandfather has dementia symptoms and he's 90. You could have another 30 years.

One advice after watching him is to never quit your hobbies until you abosolutely have to. His mental decline was sharp after giving up hobbies he had for 40 years.

Be careful with the direction of causality here. It may be that giving up his hobbies hastened his dementia, OTOH it could easily be that the onset of his dementia led to him giving up his hobbies.

I don't worry too much. Just try to pay attention to what researchers are saying and controlling what I can with my lifestyle.

I work still and will continue to work till at least 67.

I'm a developer and development manager so I get to challenge my brain routinely at work. I consume nuts, lots of and a variety of tea, a little chocolate and some red wine to help with polyphenols [1]. Oh and Omega 3 fatty acid sources. I am actively getting my weight under control.

I play puzzles, board games and other things to stimulate my brain.

[1] https://www.researchgate.net/publication/308945733_Nutrition...

As a 30 year old I think of the same. I'm trying to not spend the next 30 years being sedentary in a office.

I'm trying to pick of all kinds of outdoor hobbies I can do year around.

I've been sedentary most of my life. That has turned out to be not so good for my health. I do go workout now about 5 times a week. Been doing that for 3+ years.

I think your strategy of finding outside hobbies can be a real benefit.