The Fat That Fattens Cancer Risks

Cancer risks in older adults associated with higher levels of visceral adipose

(RxWiki News) Being overweight or obese has been linked to numerous health problems, including cancer. Researchers recently used imaging studies to evaluate the true relationship between fat and cancer.

This new study discovered that the location and type of fat men and women carried held the key to how fat impacted their cancer risks.

The overall amount of fat a woman carried impacted her cancer chances, but not a man’s, while increasing amounts of visceral fat surrounding the organs in the abdomen increased the cancer risks of both genders.

"Make time for exercise in your daily schedule."

For this study, a team of investigators — led by Rachel Murphy, PhD, a researcher at the Laboratory of Epidemiology, and Population Sciences, Intramural Research Program, National Institute on Aging, in Bethesda, Maryland — used various types of radiological imaging to study the types of fat found in older men and women.

In the study’s introduction, the authors noted that a 2008 study involving more than 280,000 cancer cases showed that greater BMI (body mass index) was linked to higher risks for many types of cancer. Adiposity (fat) is strongly related to increased risks for breast, endometrial, esophageal, pancreatic, colorectal, kidney, thyroid and gallbladder cancers.

Dr. Murphy’s team was interested to learn about the associations between fat deposits in different regions of the body (what scientists call adipose depots), cancer risks and obesity-related cancers.

Study participants included 1,179 men and 1,340 women aged 70-79 who did not have cancer. These participants were followed for 13 years.

The researchers evaluated adiposity in these individuals using BMI (body mass index - a measure of fat composition based on weight and height), X-ray and CT (computed tomography). Visceral adipose tissue (VAT), abdominal fat, fat that’s found around the muscles of the thigh and fat that appears just under the skin (subcutaneous fat) were measured.

During the study period, 617 study members were diagnosed with cancer, 224 of which were obesity-related cancers.

The total amount of fat a woman carried and visceral adipose tissue were positively associated with cancer risks among women, but not among men.

The total adipose tissue was positively linked with obesity-related cancers in women.

And total VAT was linked with obesity-related cancer risks among men, regardless of their BMI, the study uncovered.

Compared to men with less VAT, men with the most VAT had nearly three times greater risks of esophagus, pancreas, colon and rectum, kidney, thyroid and gallbladder cancers, the study found.

“These findings provide insight into relationships between specific adipose depots and cancer risk and suggest differential relationships among men and women,” the authors wrote.

Dr. Murphy said in a prepared statement, "I think it's important to realize that BMI is not the only indicator of health to concentrate on.”

These study findings were published December 4 in Applied Physiology, Nutrition, and Metabolism.

This research was supported in part by the Intramural Research Program of the National Institutes of Health, National Institute on Aging.

Review Date: 
December 3, 2013