Only thing is the genetics. his dad lived well into the 90s with dementia, they had to hole him up in a basement in a pretend office to keep him from damaging himself and others.

That said Fred jr. died of a heart attack super young. However it required a hefty case of alcoholism. As far as I know trump doesnt drink. You’d think that the food he eats would suffice but he’s almost lived twice as long as his brother with such a bad habit.