(Natural Blaze) It’s no secret that obesity is harmful to health, and recent studies have debunked the myth that one can be “fat but fit.”
Also well-established is the link between obesity and increased cancer risk, but how it actually causes cancer has yet to be fully explained.
A recent study offers more details on the association. Researchers at Michigan State University found that a certain protein released from fat in the body can cause a non-cancerous cell to turn into a cancerous one.
The research also found that a lower layer of abdominal fat, when compared to fat just under the skin, is the more likely culprit, releasing even more of this protein and encouraging tumor growth.
It is estimated that at least one-third of the population is obese. Obesity has been linked to several types of cancers including breast, colon, prostate, uterine, and kidney.
But Jamie Bernard, the study’s lead author and an assistant professor in pharmacology and toxicology, said that just being overweight isn’t necessarily the best way to assess risk:
“Our study suggests that body mass index, or BMI, may not be the best indicator. It’s abdominal obesity, and even more specifically, levels of a protein called fibroblast growth factor-2 that may be a better indicator of the risk of cells becoming cancerous.”
There are two layers of belly fat. The top layer, known as subcutaneous fat, lies right under the skin. The layer under that, called visceral fat, is the one she found to be more harmful.
In the article Do You Need a Reason to Stop Drinking Soda? Here it Is, I explained what visceral fat is and why it is so dangerous:
Visceral fat – also known as “deep fat” – wraps around your internal organs, including your liver, pancreas, kidneys, and intestines. It is much more dangerous than subcutaneous fat (the fat that you can see – the “inch you can pinch”). That’s because visceral fat (which gets its name from viscera, which refers to the internal organs in the abdomen) affects how our hormones function and is thought to play a larger role in insulin resistance – which may increase Type 2 diabetes and heart disease risk.
Excess visceral fat is also linked to an increased risk of developing cancer, stroke, dementia, depression, arthritis, obesity, sexual dysfunction, and sleep disorders.
You don’t have to be visibly overweight to be at risk. Even relatively thin people can have too much visceral fat, which is why it is often referred to as “hidden” belly fat.
Back to the study.
Here’s how Bernard and her team conducted their research:
Bernard and her co-author Debrup Chakraborty, a postdoctoral student in her lab, studied mice that were fed a high-fat diet and discovered that this higher-risk layer of fat produced larger amounts of the fibroblast growth factor-2, or FGF2, protein when compared to the subcutaneous fat. They found that FGF2 stimulated certain cells that were already vulnerable to the protein and caused them to grow into tumors.
She also collected visceral fat tissue from women undergoing hysterectomies and found that when the fat secretions had more of the FGF2 protein, more of the cells formed cancerous tumors when transferred into mice. (source)
What does this mean?
Bernard explains,
“This would indicate that fat from both mice and humans can make a non-tumorigenic cell malignantly transform into a tumorigenic cell.”
There are several other factors released from fat, Bernard said, including the hormone estrogen, that could influence cancer risk, but many of those studies have only been able to show an association and not a direct cause of cancer. She added that genetics also play a role.
“There’s always an element of chance in whether a person will get cancer or not. But by making smarter choices when it comes to diet and exercise and avoiding harmful habits like smoking, people can always help skew the odds in their favor.”
The study is published in the journal Oncogene and was funded by the National Institutes of Health.
