Food Restriction

[Guest guest]

<<Has anyone heard of this drug? Any thoughts on eating less (as

long as you get the proper nutrients, of course) to increase one's

natural life? I've heard this is true but the increase in time is

not worth the self-denial. Any comments?>>

I am excited that the life extension conversation finally made its

way toward food restriction. Food restriction is one of the only

known methods of increasing length of life that is supported by most

animal models from worms to rats. What is more interesting is that

food-restriction (30% of ad. lib.), but not energy restriction due to

exercise (same energy intake as ad.lib., but 30% of energy utilized

through exercise), increases the mean life span. Energy restriction

due to exercise acts to flatten out the mortality curve (mortality v.

time) so that the range of age of death is decreased but the age of

death is not extended (shown in rats.)

The mechanism of life extension is still not known. Proposed

mechanisms of life extension include: decreased body temperature,

altered metabolism, increased metabolic efficiency, aberrant gene

expression, changes in neuroendocrine or hormonal regulation, and

decreased DNA damage or increased DNA repair.

Another interesting note about food restriction in rodents is an

increase in voluntary activity. Contrary to intuitive thinking, food

restriction increases the activity of rodents in their cages (15% in

rats, 73% in mice.) Researchers propose that this is a survival

adaptation. In the wild, food is not presented to the rodents every

day in a little cup in the corner of the cage. They have to actively

search for new food sources. An increase in activity might increase

the chance of discovering a new food source.

Trent

Berkeley, CA