|
The study, reported in journal Circulation, 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
heart disease.
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.
Study's Findings
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, say
researchers.
Telomere length and changes can vary between people and run in families, they
note.
Possible Explanation
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.
Anti-Aging Solution
Insulin resistance and weight problems can be addressed. Healthful eating and
adequate exercise help; consult a health care professional for guidance.
Those efforts could also lower your risk of heart disease, stroke, diabetes, and
generally boost your health at any age.
By Miranda Hitti
Reviewed By Kathleen Zelman, MPH, RD, July 25, 2007.
Medically updated July 25, 2007.
SOURCES: Gardner, J. Circulation , May 3, 2005; vol 111:
pp 2171-2177. WebMD Medical Reference from Healthwise: "Metabolic Syndrome -
Topic Overview." WebMD Medical News: "Metabolic Syndrome Rising Among Young
Adults." "Metabolic Syndrome Rising Among Young Adults." WebMD Feature: "How
Antioxidants Work." "How Antioxidants Work." News release, Tulane University
Health Sciences Center.
|