how to forestall heart disease in a group of
middle-aged men with above-normal cholesterol levels. Men with the longest telomeres were half as likely to fall victim to
heart disease as were men with punier telomeres. But the difference in susceptibility
shrank after treatment with a cholesterol-lowering statin, researchers revealed in The
Lancet in 2007, suggesting that the patients
with the shortest telomeres gained the most.
“Short telomeres are as or more predictive
than conventional cardiovascular disease
risk markers” such as cholesterol levels,
Telomere tests also deliver a verdict on
a patient’s lifestyle, Blasco says. A stack of
studies suggests that not only age but also
our habits and actions can affect telomere
length. And unlike a gene
variant that hikes disease
risk, “telomeres are malleable,” Blackburn says.
CREDI TS (LEF T TO RIGH T): KEI TH WELLER/JOHNS HOPKINS MEDICINE; COUR TES Y UCSF NE WS SERVICES
Among the enemies of
our telomeres, these studies indicate, are smoking,
heavy drinking, and obesity. Long-term psychological stress might also take
a toll. In 2004, Blackburn,
UCSF health psychologist
Elissa Epel, and colleagues
reported that telomeres
were shorter in women who
said they were under the
most pressure. More recent
studies have connected
childhood trauma and prolonged depression to truncated telomeres.
By contrast, telomeres
tend to shrink more slowly
with age in people who adopt healthy habits
such as regular exercise. Longer telomeres
are also associated with positive physiological measures like higher blood levels
of omega-3 fatty acids, which are found in
fish and might protect against heart disease.
Epel, Blackburn, and colleagues reported
last year that meditation revs up telomerase,
a cellular enzyme that stretches telomeres.
If tests point to dwindling telomeres, “
people need to assess the probable causes of
telomere shortening” and consider changing their lifestyle, says Epel, who is another
of Telome Health’s co-founders.
Researchers involved with the two com-
panies acknowledge some gaps in the evi-
dence on the health impact of telomere
length. The link between short telomeres
and chronic illnesses rests on association
studies that tease out correlations between
telomere length and disease incidence, not
cause and effect. And the findings of these
studies can be inconsistent, critics say. “At
the moment, there are mixed results in some
of these studies,” says cancer biologist Alan
Meeker of JHU School of Medicine.
Predictive power. Elizabeth
Blackburn (right) says telomere tests might reveal how
well our bodies are aging.
Longtime collaborator Carol
Greider (left) is not so sure.
says: “I think we know too little to suggest
that a person [with short telomeres] is at
The notion that changing how we live
can alter telomere length also relies mainly
on association studies, Epel concedes. So
far, there are no telomere-stretching drugs,
and the placebo-controlled, blinded studies
that could nail down whether lifestyle inter-
ventions work are just getting under way.
For example, Blackburn and colleagues are
collaborating with researchers in the UCSF
urology department to determine whether
they can protect the telomeres of a group of
men who have early prostate cancer and are
therefore under stress. The patients will fol-
low a regimen, designed by diet guru and
UCSF professor Dean Ornish, that includes
regular exercise, a low-fat diet, and activi-
ties such as yoga.
Measuring telomeres is tricky as well,
experts say. Telome Health will use the quantitative polymerase chain reaction, or qPCR,
which is fast and inexpensive, Harley says.
Because most studies on telomere length in
diseases opt for this technique, it should be
easier to interpret patient results, he adds.
But Shay describes qPCR as “marginally
useful” because it provides only the average
telomere length for a group of cells. He says
that two of the telomere-measuring companies asked him to consult for them, but he is
offering his expertise to Life Length because
he feels that it uses superior techniques.
One method, called Q-FISH, involves tagging telomeres with fluorescent labels and
analyzing images of the chromosomes.
Unlike qPCR, he says, Q-FISH can identify
extremely short telomeres
within a cell. These rundown telomeres are the ones
that can nudge the cell into
senescence or suicide. Other
researchers laud a different
version of FISH developed
by Lansdorp and colleagues.
Called Flow-FISH, it relies
on a flow cytometer to measure fluorescence and gauges
average telomere length
within an individual cell.
With all these claims
and counterclaims, pediatrician and telomere biologist
Abraham Aviv of the New
Jersey Medical School in
Newark has proposed that an
perhaps the U.S. National
Institutes of Health, do an
impartial analysis of the
Whether patients will want the new tests
depends in part on how much they cost and
who will pay. Life Length charges €500
(about $700), Blasco says. Telome Health has
yet to set a price for the service, Harley says.
Both scientists agree that the early market
will likely be private clinics and “concierge
physicians,” whose patients can afford to foot
their own medical bills. But if the tests do turn
out to have predictive power, Blasco says she
hopes the Spanish national health system will
cover the costs. U.S. insurance companies
might do the same, Harley says.
But do we really want to know how long
our telomeres are? Shay thinks many people do—but he’s not one of them. “I have no
interest in knowing how long my telomeres
are,” he says. “I’m afraid to ask.”