Even if you know you will develop dementia, there's nothing really you can do to avoid it
Sometimes I think there are all these mental problems because human is not meant to last that long, just science force us to survive that much
GL with your dad
Well, if you talk about average life span, then it's less, but there were people who easily lived for a century, if practiced good simple diet and Yoga. Swami Sivananda is the oldest man in India , at 127 years, quite fit and fine , still practicing yoga daily and performing all rituals independently.
I heard yoga is helpful for much stuff, including stress which is cause of body oxidation hence reducing lifespan
Ya, science still does not understand all of that.