Experts have found the deeper the layer of fat – known as visceral fat – the more the protein encourages the growth of cancerous tumours.
Obesity, and being overweight is a major contributor to cancer risk – it is linked to breast cancer, bowel cancer, prostate cancer, uterine cancer and kidney cancer – but it is still fairly unclear why this is the case.
There are two layers of belly fat, the top layer, known as subcutaneous fat, lies right under the skin while the under layer, called visceral fat, was found to be more harmful.
Visceral fat is different to the fat which can be pinched around the middle called subcutaneous fat, which sits below the surface of the skin.
Michigan State University researchers said just being overweight isn’t the best way to determine cancer risk.
Jamie Bernard, assistant professor in pharmacology and toxicology, said: “While there have been several advances in treating cancer and improving the quality of life of patients, the number of new cases continues to surge.
“It’s important to understand the cause so we can do a better job at reducing the number of cancer cases using dietary modifications or therapeutic interventions.
“Our study suggests that body mass index, or BMI, may not be the best indicator.
“Its 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.”
The study looked at 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.
Experts found that FGF2 stimulated certain cells that were already vulnerable to the protein and caused them to grow into tumours.
Professor Bernard said: “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 favour.”
The scientists are already looking at identifying new anti-cancer compounds in her research that could stop the effects of FGF2.
Visceral fat is designed to be stored as energy, but excessive consumption of sugar foods can increase the prevalence of belly fat.
High levels of visceral fat can also increase the risk of type 2 diabetes, heart disease and dementia.
The study was published in the journal Oncogene.