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Insight
into why low calorie diet can extend
lifespan -- even if adopted later in life
July 2010--New research is giving
scientists new insight into why a restricted
diet can lead to a longer lifespan and
reduced incidence of age-related diseases
for a wide variety of animals.
Scientists have known for some time that a
restricted diet can extend the lifespan of
certain animals but this work shows how it
affects ageing mechanisms – and
significantly has also shown that the
effects occur even if the restricted diet is
adopted later in life.
The work could help scientists to better
understand, and ultimately, prevent a range
of age-related diseases in humans.
The research is being presented at the
conference of the British Society for
Research on Ageing (BSRA) in Newcastle. It
was conducted by scientists at the BBSRC
Centre for Integrated Systems Biology of
Ageing and Nutrition (CISBAN) at Newcastle
University.
Working with the theory that cell senescence
– the point at which a cell can no longer
replicate - is a major cause of ageing the
researchers set out to investigate what
effect a restricted diet had on this
process. By looking at mice fed a restricted
diet the team found that they had a reduced
accumulation of senescent cells in their
livers and intestines. Both organs are known
to accumulate large numbers of these cells
as animals age.
Alongside this the CISBAN scientists also
found that the telomeres of the chromosomes
of the mice on restricted diets were better
maintained despite their ageing. Telomeres
are the protective 'ends' of chromosomes
that prevent errors, and therefore diseases,
occurring as DNA replicates throughout an
organisms lifetime but they are known to
become 'eroded' over time.
The adult mice were fed a restricted diet
for a short period of time demonstrating
that it may not be necessary to follow a
very low calorie diet for a lifetime to gain
the benefits the scientists found.
Chunfang Wang, the lead researcher on this
project at CISBAN, said: "Many people will
have heard of the theory that eating a very
low calorie diet can help to extend lifespan
and there is a lot of evidence that this is
true.
"However, we need a better understanding of
what is actually happening in an organism on
a restricted diet. Our research, which
looked at parts of the body that easily show
biological signs of ageing, suggests that a
restricted diet can help to reduce the
amount of cell senescence occurring and can
reduce damage to protective telomeres.
"In
turn this prevents the accumulation of
damaging tissue oxidation which would
normally lead to age-related disease."
Professor Thomas von Zglinicki, who oversaw
the research, said: "It's particularly
exciting that our experiments found this
effect on age-related senescent cells and
loss of telomeres, even when food
restriction was applied to animals in later
life. We don't yet know if food restriction
delays ageing in humans, and maybe we
wouldn't want it. But at least we now know
that interventions can work if started
later. This proof of principle encourages us
at CISBAN in our search for interventions
that might in the foreseeable future be used
to combat frailty in old patients."
CISBAN is one of the six BBSRC Centres for
Integrative Systems Biology. The centres
represent a more than £40M investment by the
Biotechnology and Biological Sciences
Research Council (BBSRC) to support the
development of systems biology in the UK.
The centres are also supported by the
Engineering and Physical Sciences Research
Council.
Systems biology uses the study of a whole,
interconnected system – a cell, an organism
or even an ecosystem – with computer
modelling to better make the outputs of
biology more useful to scientists,
policymakers and industry.
Prof Douglas Kell, BBSRC Chief Executive and
keynote speaker at the BSRA Conference,
said: "As lifespan continues to extend in
the developed world we face the challenge of
increasing our 'healthspan', that is the
years of our lives when we can expect to be
healthy and free from serious or chronic
illness. By using a systems biology approach
to investigate the fundamental mechanisms
that underpin the ageing process the CISBAN
scientists are helping to find ways to keep
more people living healthy, independent
lives for longer."
