V. RELATED RESEARCH
D) Calorie/Dietary Restriction
While not substantially related to the telomeric theory of aging Dietary
Restriction is a possible adjunct to the research. It is one of the few
methods known to have any noticeable impact on the extension of life span.
Several research findings indicate that one possible reason Dietary
Restriction has this effect are related to the telomeres. In several studies
it has been shown that cellular replication is slowed and replicative
potential preserved in mice on calorie restriction. By slowing the
replicative activity in the cells the telomeres are preserved for a longer
period of time and the cells thus enter senescence later in the life cycle.
This strategy of maintaining individual cells for a longer period to delay
the shortening of the telomeres through mitotic division is an interesting
phenomena. In Dietary restricted mice it is apparently caused by a lack of
the "energy" needed to initiate mitosis. It may be possible to obtain
similar results through intervention in the cellular energy transport systems
or even by delaying the cellular signals leading to replication.
Another area where Dietary Restriction overlaps with the telomeric theory is
in it's effects on senescent cells. Dietary Restriction has been shown to
increase the initiation of apoptosis in senescent cells. The mechanism(s)
driving this action have not been identified but the effects are beneficial
to the organism. Beyond the natural effects of eliminating the damage caused
by senescent cells, studies by Dr. L. Effros have shown that elimination of
these cells also allows for their replacement by more functional cells.
Since senescence is the result of shortened telomeric length, Dietary
Restriction may recognize this state as damage. Possibly when both the
energy level is insufficient for replication, as shown above, and the p-53
gene is expressed as a result of telomeric shortening then the cell initiates
apoptosis. This is just a hypothesis but one I feel deserves to be explored.
(Next:Telomeres and Growth Factors)
Thomas Mahoney, Pres.
Lifeline Laboratories, Inc.