Mom's genes may affect how fast you age
Eating well, sleeping well and exercising
may help keep people young at heart, but
mutated genes passed down from mothers
may also predetermine aging rates, new
research suggests.
Aging manifests itself in a variety of age-
associated diseases as well as changes
in physical appearance , and occurs at
different rates in different people.
Scientists have previously attributed aging
to cell damage accumulated throughout
life, but have not closely considered how
aging rates might be inherited.
Now, a group of researchers based at the
Karolinska Institute in Sweden and the
Max Planck Institute for Biology of Ageing
in Germany have found that damaged
DNA in the mitochondria also known as
the powerhouse of the cell, because this
is where sugars break down into usable
energy partly control the rate of aging in
experimental mice. [5 Reasons Aging Is
Awesome ]
Mitochondrial DNA contains genes only
from mothers. The researchers report
their findings August 21 in the journal
Nature .
"What we previously had demonstrated
was that the mitochondrial DNA acquired
damage as the animals age," study
researcher Nils-Gran Larsson, a
researcher at Max Planck Institute, told
LiveScience. "But now, we also report that
some of this damage is already present at
birth, and is transmitted from mother to
child."
Mitochondrial DNA differs from the DNA
that resides in the nucleus of cells, which
comes from both parents.
The researchers found that mitochondrial
DNA becomes damaged over time, and the
cell's energy production gradually
becomes disabled and contributes to
aging, Larsson said in a statement.
To determine the effects of mitochondrial
DNA damage on aging, the team bred
laboratory mice with varying degrees of
such DNA damage, and then estimated
their aging rates by measuring aspects of
fitness such as weight, fertility and red
blood cell count.
The team found that increased levels of
damage in the mice correlated with
reduced levels of fitness. Still, the relative
influence of mitochondrial DNA damage
versus environmental stressors in aging
remains unclear.
While the findings may have interesting
implications for aging rates in humans
, they also require additional research,
Larsson said.
"We have used a set of experimental
conditions to establish our results, and we
think they are applicable to humans, but
of course, this has to be proven through
human studies," Larsson told LiveScience.
The team next plans to study the relative
role of damaged mitochondrial DNA in
aging by genetically engineering flies to
have decreasing levels of mutated
mitochondrial DNA from one generation
to the next. They hope their research will
provide the groundwork for other
researchers to study the human
implications of their findings, Larsson
said.
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