Tomiko
Kadonaga, who turned 100 on Jan. 8, will tell you shes had an easy
life. Others would say differently. Kadonaga, who was born in B.C. to
Japanese-Canadian parents, was placed in an internment camp during the
Second World War, housed with her husband,The feeder is available on
drying miningtruck equipped
with folder only. Saul, in buildings intended for livestock. The stall
where I was had a little blue card outside that said, First Prize Cow,
she says with a wry smile. I thought, At least Im first prize. Her
godmother offered Saul a job on a farm in Port Hope, Ont., and a way
out; leaving all their possessions behind, they moved to the area in
1942, and had a daughter. Saul died of esophageal cancer in 1989.
Today,
Kadonaga, who lives alone in a neatly kept townhouse in Torontos north
end, is the picture of contentment. Her legs bother her a bit, she says
(she gets around with a flowery purple cane), but otherwise shes in good
health. In Canada, average life expectancy is 81, yet more people than
ever are living to be 100. In 2011, we had 5,825 centenarians, according
to Statistics Canada, up from 3,795 10 years before. As life expectancy
continues to rise, it could hit over 17,000 by 2031. Why some people
outlive almost everyone elseand remain in good health, even into very
old ageremains one of the grand questions of science. Researchers have
credited everything from diet and exercise to genetics. A clue to the
secret of Kadonagas longevity, one were only starting to understand,
lies buried deep within her cells: the tiny bits of DNA that cap the
ends of her chromosomes, called telomeres.
Telomeres
shorten as we age, but the telomeres of centenarians are remarkably
long, according to Gil Atzmon at the Albert Einstein College of Medicine
in New Yorkmore like those of people three decades younger, or even
younger than that. Often compared to the plastic ends that keep
shoelaces from fraying, telomeres prevent chromosomes from unravelling
and fusing to each other. Each time a cell divides, some of the telomere
is lost; when it becomes too short, the cell dies. Telomeres are
protected by a powerful anti-aging enzyme, one produced by our own
cells: its called telomerase, which rebuilds telomeres and protects them
from wearing down, a discovery that won scientists Elizabeth Blackburn,
Carol Greider and Jack Szostak the Nobel prize in 2009. Healthy people
with longer telomeres seem to be at lower risk of age-related illness,
such as heart disease, diabetes and cancerthe main diseases that stop us
in our tracks today.
A
growing number of researchers say telomere length is a critically
important indicator of how old we really are, and of how many healthy
years we may have in front of us. A new industry is sprouting up around
the science of longevity, offering telomere testing to the publicand
Nobel laureate Blackburn is a notable part of it. Her company, Telome
Health , is set to launch a telomere test later this year, joining a
handful of others that already do. On May 15, Blackburn will be in
Toronto to give a lecture sponsored by Executive Health Centre, a
private clinic that offers telomere testing in Canada. Like a
cholesterol or blood-pressure test, telomere testing could one day
become standard in doctors offices.
And
maybe in the future, well be able to slow or reverse the effects of
agingthe vision of researchers searching for ways to boost telomerase, a
goal already achieved in lab mice. Some are already marketing so-called
telomerase activators to a public hungry for ways to stop the clock,
although no such drugs have been approved. With so many companies
rushing to come on board, theres a lot of weird stuff going on out
there, cautions Jerry W. Shay of the University of Texas Southwestern
Medical Center, an expert on cell biology and telomere length.
Even
telomere testing isnt without controversy. Greider, Blackburns former
graduate student, insists that public testing is premature. Dr. Peter
Lansdorp, another prominent expert on telomere biology, agrees. Its too
early, and its not supported by scientific data, he contends. But in an
unpublished study presented in late 2012, Blackburn and her colleagues
tracked 100,000 people (their average age was 63), and found that those
with shorter-than-average telomeres had a 25 per cent greater risk of
dying, from any cause, over three years. Telomere shortening is a
dynamic process, and length can go up and down through life; theres
still a lot to learn, but what happens to telomeres really does predict
what happens to you later on, says Blackburn, whos based at the
University of California, San Francisco (UCSF).
For
those whod like a glimpse into their longevitya hint at true biological
agescientists say they can peer at the tiny caps on their chromosomes
and, for better or worse, tell them what they see.
To
scientists who study aging, a persons birth date is increasingly
irrelevant. Theres an idea that we can do nothing about age, says Felipe
Sierra, director of the U.S. National Institute on Agings division of
aging biology, which funds research into everything from stem cells to
telomeres. While that is true of your chronological ageyou have a birth
certificate, and thats ityou can affect the rate of aging. Ultimately,
he says, chronological age is not so important. He calls telomere length
a good biomarker of aging, but wont comment on whether the public
should be seeking out tests.
Scientists
are still figuring out what speeds up telomere shortening. Chronic
stress seems important. With UCSF psychologist Elissa Epel, Blackburn
studied the telomeres of mothers of children with long-term illnesses.
Compared to moms of healthy kids, they had shorter telomeres and less
telomerase. We repeated this with spouses who were caretakers of
Alzheimers patients; it showed the same result. Other studies have
revealed that victims of domestic abuse, or those who suffer from
untreated depression, also have shortened telomeres, putting them at
greater risk of age-related disease. Shorter telomeres have been
associated with cardiovascular disease, some types of cancer, diabetes,
osteoperosis, dementia and other conditions.Compare prices and buy all
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Blackburn
decided to transfer her technology out of the university, to cope with
demand. All sorts of people were wanting to find out about telomere
length, says Blackburn. We had in our minds it would be interesting for
people to know about their health status.
Still,
the million-dollar question, as Telome Health president Calvin Harley
calls it, remains what can be done about short telomeres.Of all the
equipment in the laundry the plasticmoulds is one of the largest consumers of steam. Studies suggest lifestyle interventionsdiet,Learn how an embedded microprocessor in a iccard can
authenticate your computer usage and data. exercise, meditationcould
help slow down telomere shortening or boost telomerase activity, but its
still early days. Harley insists that telomere testing is valuable. He
compares it to a check-engine light, evidence your cellular aging may be
accelerated. A Canadian, he first got his telomeres tested in the late
1980s, when he was a professor of biochemistry at McMaster University.
Hes been charting them on and off since. At times when he was under
stress, not exercising or eating as well as I should have been, he saw a
slight dip in his telomere length, which motivated him to make changes.
Telome
Health will be launching in many countries, including Canada, later
this year; a few others are already offering telomere testing, such as
Life Length, based in Madrid, and SpectraCell Laboratories, in Houston.
(Testing is typically done with a blood sample; Telome Health will use
blood and saliva.)
Telomere
tests are generally ordered by a doctor or health care professional on
behalf of the patient. While Telome Health hasnt announced how much it
will cost, Life Length charges about $590 to physicians,A quality paper
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make your company's presentation stand out. although patients could be
asked to pay more. Executive Health Centre in Toronto offers a telomere
performance program that tests a patients telomere length, then
prescribes interventions (from lifestyle changes to nutritional
supplements or hormone replacement) based on results. For years, Ive
been explaining to people that lifestyle affects aging, longevity and
healthspan, says chief medical officer Dr. Elaine Chin. Now I have a
marker to say, Here you are on a continuum of telomere length.
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