effects on health over the long-term.
New data from studies of fruit flies also
suggest that robust circadian rhythms
are one key to a long and healthy life.
Many scientists assume that circa-
dian clocks would give
organisms an evolution-
ary advantage. “Organisms
need a mechanism to pre-
dict changes in the environ-
ment before they occur,”
says Michael Nitabach, a
physiologist and geneti-
cist at Yale School of Medi-
cine. “Any organism that
can predict what’s going
to happen is going to have
a selective advantage over
an organism that can’t.”
Yet somehow reindeer
seem to get along without working clocks,
according to a study published March 23
in Current Biology. And fruit flies that
don’t have functioning circadian clocks
seem to do just as well when raised in a
laboratory as flies with fully functioning
clocks, says Natraj Krishnan, a physiolo-
gist at Oregon State University in Corval-
lis. But in the wild, flies may encounter
stresses that could change the game,
so Krishnan and his col-
leagues decided to expose
lab flies to a mild stress and
see if having a clock made a
The researchers exposed
normal flies and flies lack-
ing the clock gene period
to one day of high oxygen,
which can set off harmful
chemical reactions that
damage DNA and pro-
teins. Neither group of
flies was bothered much
by oxygen stress if the flies
were exposed when young. But middle-
aged flies lacking period did not fare
as well. Compared with normal flies,
when exposed at 35 days old the mutant
flies had a 20 percent shorter life span.
changes in the
occur ... to have
Oxygen-damaged proteins also built up
faster in elderly mutant flies than in control flies, the researchers reported in the
These results indicate that circadian
clocks may help control more than just
daily rhythms of life, Krishnan says. “I’m
pretty sure that anything that messes up
the phase of the clock probably affects
aging and life span,” he says.
So daily clocks might be one of the
important things determining when it’s
“your time.” After all, circadian rhythms
tend to wind down in elderly people and
rodents. Further research may suggest
ways to reset the health and aging clock.
And that, in turn, could underscore yet
again the most important lesson of circadian clocks: that timing is everything.
s R. Silver and J. LeSauter. “Circadian
and homeostatic factors in arousal.”
Annals of the New York Academy of
Sciences. May 2008.
Over 11 Million Victims
of Identity Theft Last Year.
Source: Javelin Strategy & Research. “2010 Identity Fraud Survey Report.” February 2010.
ENROLL TODAY AND GET:
30 DAY RISK-FREE* TRIAL
USE PROMO CODE:
*At the end of the 30-day free period your card will be billed automatically ($10.00
monthly/$110.00 annually) unless you cancel within the 30-day period. You can cancel anytime without penalty by calling 1-800-LifeLock. Offer is for new LifeLock members only.
Help Protect Yourself
Identity theft is one of the fastest growing crimes in the nation. Over 11 million Americans fell victim to the crime in
2009, at a cost of over $54 billion. (Source: Javelin Strategy &
Research. “2010 Identity Fraud Survey Report.” February 2010.)
LifeLock, the leader in identity theft protection, helps
protect your identity – even if your information falls into
the wrong hands. As a LifeLock member, if you become a
victim of identity theft because of a failure in our service,
we’ll help you fix it at our expense, up to $1,000,000.
(Restrictions apply. Call for details. Due to New York State
law restrictions, the LifeLock $1 Million Total Service Guarantee cannot be offered to the residents of New York.)
Call 1-888-591-0194 and use promo code ‘ID’ to try LifeLock risk-free* for 30 days.