A. New Evidence that the Human Maximum Age Span
is Rising
Narrator:
This is Science Today. For more than a century,
the oldest age at death in humans has been slowly
rising. John Wilmoth, a University of California,
Berkeley demographer who based his data on pristine
Swedish death records, says their findings dispel
previous beliefs that the maximum human life span
had a set end-point of 120 years.
Wilmoth:
A
lot of people have been asking me, "well, does this
mean we could all live to be 120"? No, you have
to remember these are extremes. We're talking about
the world record and how the world record is changing
over time.
Narrator:
Currently, the world record is 122 years for women
and 115 years for men.
Wilmoth:
Those records will probably be broken in the future,
but what we show with Sweden is that those kinds
of records are going up at a rate of about one-year
every decade, in recent decades. And before that,
they were going up about one year of age for every
two decades. So what we're showing is that the human
life span is malleable. It's not a fixed biological
constant.
Narrator:
For Science Today, I'm Larissa Branin.
B.
UC Researcher Develops Odor-free Soc
Narrator:
This is Science Today. A University
of California, Davis researcher has developed a
product that will score points in locker rooms and
homes alike - odor-free, cotton socks. Gang Sun,
a professor in the Division of Textiles and Clothing
took non-toxic chlorine molecules and bonded them
to cotton fibers. Unlike some antibacterial products
on the market, Sun says chlorine can kill germs
without generating resistance.
Sun:
It's different from the antibiotics
because the antibiotics kills the germs by a kind
of biological process. This biological process also
can easily generate the resistance from the germs
because most of the antibiotics only target one
enzyme. If the enzyme changes a little bit, the
enzyme survive and the whole germ will survive and
also the whole germ will develop the resistance.
Narrator:
But there's no known resistance to chlorine.
Sun:
Chlorine has been used for almost
exactly a hundred years as a drinking water disinfectant.
No resistance.
Narrator:
For Science Today, I'm Larissa Branin.
C.
A Device that Significantly Decreases Epileptic
Seizures
Narrator:
This is Science Today. A nationwide
team of researchers led by UCLA, has found that
after one year of therapy, an electric, pacemaker-like
device can significantly benefit epileptics who
don't respond to standard drug treatment for their
seizures. Evelyn Tecoma, director of the Epilepsy
Center at the University of California, San Diego,
says the device, called the vagus nerve stimulator,
is implanted in the chest and delivers small pulses
of electricity to the vagus nerve.
Tecoma:
The vagus nerve is a nerve that's
present in the neck. There's one on each side. It's
in the general vicinity of the carotid artery, which
you can feel if you take your pulse in your neck.
Narrator:
This form of therapy, known as
vagus nerve stimulation, or VNS, reduces seizures
by changing blood flow in the brain. Tecoma says
most patients do well with the stimulus coming on
every five to ten minutes.
Tecoma:
It comes on for about thirty seconds and it provides
just a little stimulus of electricity that the patient
can perceive, but it's not painful. It's not uncomfortable
and it produces a little tickling or little tingling
sensation in the neck.
Narrator:
For Science Today, I'm Larissa Branin.
D.
The American Heart Association to Revise Food Guidelines
Narrator:
This is Science Today. The American
Heart Association has just revised its dietary guidelines
to emphasize the use of common sense in choosing
what to eat, rather than just going by fat and nutrient
percentages. Dr. Ronald Krauss, a researcher at
the Lawrence Berkeley National Laboratory, who wrote
the new report, says in the past, there was a strong
focus on dietary fat percentage and cholesterol
intake.
Krauss:
There is a tremendous amount of individual variability
in the way that cholesterol levels respond to this
type of diet across the population. And there's
more and more evidence that this is due to genetic
differences among individuals that help to determine
blood cholesterol profile and blood cholesterol
levels, as well as the response to diet.
Narrator:
So Krauss says the heart association is now
recommending people tailor daily menus to their
risk of heart disease and stroke.
Krauss:
It's more and more appropriate for people to treat
their risk and to work on that basis rather than
assuming that we can prescribe something that would
be effective in reducing heart disease risk in everybody.
That just isn't going to happen.
Narrator:
For Science Today, I'm Larissa Branin.
E.
Serious Birth Defects Prevented by Folic Acid-fortified
Foods
Narrator:
This is Science Today. Three years ago, the Food
and Drug Administration ordered manufacturers to
begin fortifying food with folic acid, a B vitamin,
which prevents serious birth defects in which the
fetal brain and spine are malformed. Dr. Patrick
Romano of the University of California, Davis, found
that folic acid fortification could potentially
save millions of dollars in medical costs. But Romano
admits it would be best to improve the American
diet overall.
Romano:
If we could really change the American diet and
get people eating more fresh vegetables that have
fiber, have folic acid, as well as other vitamins
in them, then we could prevent not just neural tube
defects, but also some cases of breast cancer, some
cases of colon cancer, some cases of heart disease.
So the potential health benefits would be enormous.
Narrator:
But it seems that's easier said than done.
Romano:
People have been telling us for years
that we need to eat more fruits and vegetables.
And yet, we've seen very little change in the American
diet.
Narrator:
For Science Today, I'm Larissa Branin.
