
  Diet and health: less is more


             The old  expression,  meaner than a junkyard dog, implies
        that chronically underfed animals are hardier souls than their
        pampered, well-fed relatives.   It  is  a matter of scientific
        record that  they  have  fewer illnesses, apprarently  because
        their immune systems are thogher.

             But though   researchers   know   the   effects  of  diet
        restriction, they were in  the  dark  as  to  why  until  this
        summer, when Robert A. Good of the University of South Florida
        in St.  Petersburg and some co-researchers  turned  up  a  few
        interesting clues.

             Reporting in   the  June  issue  of  PROCEEDINGS  OF  THE
        NATIONAL ACADEMY  OF SCIENCES,  they  demonstrated  that  mice
        prone to autoimmune disease naturally manufacture two to seven
        times the normal amount of a type of white blood cell involved
        in the production of auto-antibodies, which attack  the body's
        own substances.

             By consistently  restricting the diets of the autoimmune-
        prone mice to 60% of their normal  food intake, they were able
        to bring  these  potentially  harmful  B-cells   down   to  an
        acceptable level.   This  seems  to  explain  why  chronically
        underfed animals are less vulnerable to immune diseases.

                             The Fasting Worms

             Experimental tests conducted in the 1930's at the Zoology
        Department of the University  of  Chicago  showed  that worms,
        when well-fed, grew old, but by fasting them  they  were  made
        young again.

             In one  experiment worms were fed as much as they usually
        eat, except one worm, which was isolated and alternatively fed
        and fasted.  The isolated worm  was  alive and energetic after
        19 generations  of  its relatives had lived out  their  normal
        lifespans.

        Professor C.M. Childs said:

              "When worms are deprived of food, they do not die of
               starvation in  a  few  days.   They  live for months on
               their own tissues.  At  such  time  they become smaller
               and may  be  reduced  to a fraction of  their  original
               size.  Then  when  fed  after such a fasting, they show
               all the physiological  traits  of  young  animals.  But
               with continued  feeding,  they  again  go  through  the
               process of growth and aging (and die).

               One group of worms was well fed and every three or four
               months passed   through   the   cycle   of   aging  and
               reproducing.  Another  group was given just enough food
               to maintain the worms at a constant size but not enough
               to make them grow.

               These worms remained in good condition without becoming
               appreciably older as long as the experiment continued,
               which was three years."

        The life-span extension of these worms was the equivalent of
        keeping a man alive for 600 to 700 years.

        The big  question,  of course, is - do worms  that  don't  die
        contribute much to the soil?

        END

