Relating to
long life, from the Greek roots
macro- 'long' and
bio- '
life', of course, the same roots as the modern
macrobiotic. (Actually macrobiotic dates from the eighteenth century.) The difference seems to be that macrobiotic is that which (specifically food which) promotes long life; while macrobian relates to long-lived people.
Ambrose Bierce in his Devil's Dictionary has an entry for macrobian, which I shan't quote in full, especially not the dull and long verse he signed with the name Venable Strigg. But it begins
One forgotten of the gods and living to a great age. History is abundantly supplied with examples, from Methuselah to Old Parr, but some notable instances of longevity are less well known. A Calabrian peasant named Coloni, born in 1753, lived so long that he had what he considered a glimpse of the dawn of universal peace. Scanavius relates that he knew an archbishop who was so old that he could remember a time when he did not deserve hanging. In 1566 a linen draper of Bristol, England, declared that he had lived five hundred years, and that in all that time he had never told a lie.
I can't recall seeing the word used in proper English apart from Bierce, but
North Korea seems to have found it useful. Let me just quote
an excerpt from one of their fascinating press releases.
PYONGYANG, MARCH 6 (KCNA) -- THE NUMBER OF MACROBIANS IS ON A STEADY RISE IN KOREA. THE LAST DECADE HAS WITNESSED FIVE TIMES AS MANY MACROBIANS ABOVE 90 YEARS OF AGE AS THE PREVIOUS ONE DID. THOSE ABOVE A HUNDRED YEARS OF AGE IN 1993 WERE NEARLY THREE TIMES AS MANY AS IN 1971. THIS IS ATTRIBUTABLE TO THE STATE'S DEEP CARE AND FAVORS FOR THE HEALTH OF OLD PEOPLE.
...
IT ISSUES A MAGAZINE "SENILITY AND HEALTH" AND AN INFORMATION BULLETIN REGULARLY TO DISSEMINATE KOREA'S ACHIEVEMENTS IN JUCHE-BASED RESEARCH INTO MEDICAL SCIENCE TO SCORES OF COUNTRIES OF THE WORLD AND POSITIVELY CONTRIBUTE TO THE DEVELOPMENT OF INTERNATIONAL GERIATRICS. KOREA WILL HAVE A LARGER NUMBER OF "FAMILIES AND VILLAGES OF MACROBIANS."