Extra Weight May Age You Faster
Evidence seen in white blood cells, say researchers
May 25, 2005 -- You probably already know that gaining weight isn't good for
you. Now, a new study shows that extra pounds may literally make you old before
The news, reported in Circulation earlier this month, doesn't
center on gray hair or wrinkles. Instead, it delves down into the blood. White
blood cells show telltale signs of aging when weight gain or insulin resistance
is present, the study shows.
Insulin resistance means that the body's ability to control blood sugar is
faltering. It can be a warning sign of looming health risks including diabetes
and the metabolic syndrome, a group of abnormalities that raises the risk of
The body makes insulin, a hormone, to handle blood sugar. In insulin
resistance, insulin goes unheeded to some degree, so the body works harder to
make more insulin to get the job done.
The results came from the Bogalusa Heart Study, a long-term research project
including black and white adults and children in and around Bogalusa, La. The
researchers included Gerald Berenson, MD, who started the study in 1973 to
track heart disease risk factors.
Back then, many participants were in grade school. Now, Berenson and
colleagues studied them as adults.
The study included 49 black and white young men and women. All had their
height, weight, and blood sugar (glucose) levels recorded at least twice
between 1988 and 2001.
There was one more piece of key data: the length of their white blood cells'
telomeres. Telomeres are part of the cells' chromosomes, which house DNA. Those
telomeres naturally get shorter with age.
Shorter telomeres were associated with weight gain and insulin resistance,
Telomere length and changes can vary between people and run in families,
What made the telomeres shrink faster than normal? The study doesn't settle
that, but cell-damaging free radicals and inflammation might be responsible,
say the researchers.
For instance, they say that obesity is associated with increased
inflammation because fat tissue is a major source of inflammatory chemicals.
"Inflammation promotes an increase in white blood cell turnover, which
would enhance telomere attrition," they write.
In other words, inflammation burns out white blood cells faster, and the
effort of replacing them wears down the telomeres.
Insulin resistance and obesity are also associated with free radical damage,
the study explains. Those damaged cells become "free radicals" that can
hurt DNA in normal cells, laying the groundwork for health problems.
Insulin resistance and weight problems can be addressed. Healthful eating
and adequate exercise help; consult a health care professional for
Those efforts could also lower your risk of heart disease, stroke, diabetes,
and generally boost your health at any age.