(Dubai Health & News) New research findings show that extra body fat doesn't
just weigh you down. Scientists now have evidence that too many fat cells prompt
ongoing reactions in the body that may increase cancer risk.
If Elizabeth Platz, Sc.D., Assistant Professor of Epidemiology at Johns Hopkins
University, and her colleagues are right, excess fat may alter the body's basic
functioning in ways that raise risk for cancer and other diseases.
Research has already shown that obesity boosts levels of hormones such as
estrogen, for example, which increase risk for breast cancer in post-menopausal
women. Too much body fat, especially in the abdomen, also increases insulin
resistance, priming the body for diabetes.
Now, recent findings by Dr. Platz and her research team suggest that obesity,
especially around the waist, may also influence the body's inflammatory response
so that risk for colon cancer is higher.
Too Much of a Good Thing
Inflammation is the body's first response to infection or injury. It's essential
to healing, but it can go awry. Many scientists suspect that chronic low-level
inflammation of body tissues underlies a lot of disease processes. How does this
happen?
Substances called cytokines are part of the body's inflammation response to help
with fighting infection and healing wounds. Cytokines are made by white blood
cells, but fat cells can make cytokines too.
"In addition to fighting infection, cytokines help with wound repair by
stimulating tissue growth," explains Dr. Platz. "Our research suggests that when
the body has an oversupply of fat cells, those cells release too many cytokines.
This boosts the body's inflammatory response and causes damage to cells and
their DNA."
"Where there is genetic damage plus stimulation for cells to grow, the chance of
cells growing out of control and becoming cancer is increased," she says.
A Link to Diabetes and Cancer
In a previous study, funded in part by American Institute for Cancer Research (AICR),
Dr. Platz and her colleagues showed that people who were obese (with a body mass
index of 30 or higher) had a higher risk of colon cancer. People who were
diabetic or had poor glucose control also had increased risk.
What's more, a follow-up study, also supported in part by AICR, found that
people who had elevated blood levels of a protein called CRP (or C-reactive
protein) also had a higher risk of colon cancer. CRP is a marker for the
presence of low-level inflammation somewhere in the body.
Some cancers are known to be associated with persistent inflammation that's
related to chronic infection. For example, people infected with one of the
viruses that cause hepatitis are more susceptible to liver cancer. Chronic
infection with Helicobacter pylori, a bacterium that lives on the lining of the
stomach, increases risk for stomach cancer. People with inflammatory bowel
disease have above-average rates of colon cancer.
The idea that fat cells could be actively involved in promoting inflammation is
a relatively new one, says Dr. Platz. "There is more to being fat than carrying
around excess weight. People should begin thinking of excess body fat as
actively harmful to their health."
