CRON's Cancer Protection Mechanism?

[Guest guest]

Hi folks:

This may, at least in part, explain how CRON reduces cancer incidence.

" High Blood Sugar Raises Cancer Risk

Tuesday, January 11, 2005

By Salynn Boyles

A study involving more than a million people offers some of the best

evidence of an association between diabetes and an increased risk of

cancer.

Researchers have found having elevated fasting blood sugar levels

increased the risk of dying from cancers of the pancreas and liver,

and several other malignancies.

Obesity has been associated with many negative effects on health,

including some types of cancer.

Because investigators took into account obesity, which is the biggest

risk factor for type 2 diabetes, the findings indicate that having

diabetes or being at risk for it is an independent risk factor for

developing cancers.

The study was conducted in Korea, which has a much lower incidence of

obesity and type 2 diabetes than the U.S. Only about a quarter of the

population is overweight or obese, compared with more than half of

Americans.

The research is reported in the Jan. 12 issue of the Journal of the

American Medical Association.

" What this means is that the public health implications of this

finding would be much greater for the United States than for Korea, "

study author Samet, MD, tells WebMD. " Certainly, obesity

drives blood sugar and obesity is a known risk factor for certain

cancers. So this could be one of the ways in which obesity increases

this risk. "

One in 31 Cancer Deaths

Approximately 150 million people worldwide have diabetes, but that

number is expected to double within the next two decades as the

population ages and becomes more obese and less active. While the

association between diabetes and heart disease (search) is well

established, the role of diabetes in cancer has been less well

understood.

In this study, researchers examined the relationship between fasting

blood sugar levels and diabetes and the risk of specific cancers in

just under 1.3 million Koreans enrolled in a government-run health

insurance plan. During 10 years of follow-up, there were 20,566

cancer deaths among the men in the study and 5,907 cancer deaths

among women.

After controlling for known cancer risk factors such as smoking and

alcohol use, researchers found that the men in the study with the

highest fasting blood sugar levels (those greater than 140 mg/dl)

were 29 percent more likely to die of cancer than men with the lowest

levels (those less than 90 mg/dl). The difference among women with

the highest and lowest blood sugar levels was 23 percent.

The association was strongest for pancreatic cancer (search), with

high blood sugar and diabetes (defined as a fasting blood sugar

greater than 125mg/dl) almost doubling the risk for men and more than

doubling the risk for women. An increased risk with high blood sugar

or diabetes was also found for colorectal cancer (search) and cancers

of the esophagus and liver in men, and cancers of the liver and

cervix in women.

The researchers estimated that 848 of the 26,473 total cancer deaths

reported during the 10-year period could be attributed to diabetes

and high blood sugar levels.

Lowering Risk

The latest population figures suggest that 64 percent of Americans

are overweight or obese, defined as having a body mass index (BMI) of

25 or more. Roughly a third of U.S. adults are obese, defined as

having a BMI of 30 or more. BMI is determined by calculating height

and weight. Being obese is strongly associated with numerous medical

conditions and higher death rates.

According to the National Center for Health Statistics rates of

obesity have increased from 12.8 percent in 1976-1980 to 22.5 percent

in 1988-1994 and 30 percent in 1999-2000.

In an editorial accompanying the study, Kathleen Cooney, MD, and

Gruber, MD, PhD, of the University of Michigan Medical

School, wrote if current trends continue, 40 percent of Americans

will be classified as obese within five years and type 2 diabetes

rates will rise dramatically.

Obesity has long been considered a risk factor for many types of

cancer, including postmenopausal breast cancer and cancers of the

pancreas, colon, endometrium, esophagus, kidney, gallbladder, and

colon.

Cooney and Gruber noted that while the new findings directly

implicate diabetes as a risk factor for many of these cancers, they

don't completely explain the obesity/cancer link.

" Several complex physiological changes also result from obesity,

including alterations in sex steroid levels, " they wrote.

American Cancer Society epidemiologist Carmen , MD, says the

findings strengthen the argument that keeping weight under control is

key to preventing disease.

" This study clearly shows that diabetes increases the risk of certain

cancers, and being overweight is a big risk factor for diabetes, "

tells WebMD. " The message is clear. You can lower your risk

for these cancers by controlling your weight and maintaining a

healthy lifestyle that includes physical activity. "

SOURCES: Jee et al. Journal of the American Medical Association, Jan.

12, 2005; vol. 293: pp 194-202. M. Samet, MD, MS, Department

of Epidemiology, s Hopkins Bloomberg School of Public Health,

Baltimore, Md. Kathleen Cooney, MD, departments of internal medicine

and urology, University of Michigan Medical School, Ann Arbor, Mich.

Carmen , MD, MPH, epidemiologist; and spokeswoman, American

Cancer Society, Atlanta. "