It says: 14.2 out of 100 men of European ethnicity who share Robin Powell’s genotype will develop Alzheimer’s Disease between the ages of 50 and 79.
Apparently, according to 23andMe, the normal incidence in european men in that age range is 7.2%, so it’s “only” twice as likely.
In that case, your current age matters a lot. If you are substantially below that age then there’s a high likelyhood that before you hit that age range we will have some effective treatments for Alzheimer’s (although I think people are generally overly optimistic about a lot of the current treatment suggestions).
I’m 35, and I’m worst-casing this, and as I said Alzheimer’s is, I presume, only one such thing to be worried about.
So your 14% is for a range that overlaps with a 19% range… Might want to investigate your risk a little more carefully, eg. what’s your total lifetime risk with that info compared with the base-rate lifetime risk for people with your life expectancy?