The King of Madison Avenue, Kenneth Roman’s recent biography of legendary adman David Ogilvy, provides this interesting origin of a time-honored bromide about staying healthy.

In the 1920s, Mathers [the precursor of agency giant Ogilvy & Mather] pioneered generic (non-branded) advertising with its “Eat More Fruit” campaign and its enduring slogan “An apple a day keeps the doctor away.”

Who knew?