Is Your Belly Fat Raising Your Cancer Risk?
Most of us tend to think about belly fat in terms of how it looks and what pant size we wish we could fit into. Some of us consider the health implications: an uptick in the risk of insulin resistance, Type 2 diabetes and even heart disease. Very few of us think about cancer.
However, obesity – which affects roughly one-third of American adults – is believed to contribute to 20 percent of all deaths from cancer in the United States. And now, a new study from Michigan State University reveals that, when it comes to fighting fat-related cancer in overweight (and even some normal-weight ) folks, belly fat is enemy No. 1.
Abdominal Fat and Cancer: The Surprising Connection
The fat on your frame is all but the same, and it exists in two distinct layers. The top, pinchable layer, which sits directly above your skin, is called subcutaneous fat. The deeper layer of fat, which takes up residence in and around your organs and makes for a rounder belly, is termed visceral fat, abdominal adiposity or belly fat.
While some subcutaneous and visceral fat is normal, mounting research shows it’s excess visceral fat, rather than subcutaneous fat, that has the biggest impact on health. For example, one review published in the Journal of Cardiovascular Disease Research concluded that abdominal obesity, regardless of body mass index (a ratio of height and weight), is strongly linked to an increased risk of cardiovascular disease. Meanwhile, a 2016 study published in the International Journal of Obesity found that 30 percent of Americans with so-called “healthy” weights actually have poor cardiometabolic health, with symptoms including insulin resistance, excessive inflammation and other conditions long associated with obesity. In other words, slim-looking folks with bellies can be far more unhealthy than people who are bigger all around.
Now, researchers have found that excess belly fat’s risks go beyond heart health. To investigate how belly fat – not just fat in general – affects the risk of cancer, Michigan State University researchers examined mice and found that their visceral fat tissue produced large amounts of a protein, called fibroblast growth factor-2 or FGF2, that can cause a formerly healthy cell to turn cancerous.
“We found that the largest contribution of this protein in the circulation came from the visceral adipose tissue, because when we surgically removed the visceral fat, the blood levels of this protein were almost undetectable,” says lead study author Jamie Bernard, assistant professor of pharmacology and toxicology at Michigan State University.
What’s more, Bernard collected samples of visceral fat tissue samples from women undergoing hysterectomies and evaluated their levels of the cancer-promoting protein. Upon transfer into mice, the samples containing higher levels of FGF2 triggered more cancer tumors, linking the protein, produced from visceral fat, to cancer formation in humans. (For ethical reasons, scientists can’t try to give humans cancer.)
