This paper
http://www.jneurosci.org/content/36/37/9659
was mentioned in a NY Times article
http://www.nytimes.com/2016/12/31/opini ... ailed&_r=0
with the conclusion:
"Superagers are like Marines: They excel at pushing past the temporary unpleasantness of intense effort. Studies suggest that the result is a more youthful brain that helps maintain a sharper memory and a greater ability to pay attention.
This means that pleasant puzzles like Sudoku are not enough to provide the benefits of superaging. Neither are the popular diversions of various “brain game” websites. You must expend enough effort that you feel some “yuck.” Do it till it hurts, and then a bit more."
I didn't see any mention of APOE4 status among the superagers.