Stomach fat releases proteins that fuel the growth of cancerous cells, research has found.
Scientists knew that obesity is a known risk factor for cancer – but little was known about exactly how fat helps turn healthy cell turns into a malignant ones, until now.
Belly fat is known as visceral fat, and is located deep inside the abdominal cavity and surrounds the internal organs, such as the liver, pancreas, and intestines.
Unlike subcutaneous fat (the kind that sits directly beneath the skin), it tends to be more ‘metabolically active’, the researchers explain, secreting higher levels of inflammatory substances that can trigger cancer.
Visceral fat, which is stored within the abdominal cavity and surrounds the internal organs, produces a protein that fuels the growth of cancer, a US study has found
‘There’s always an element of chance in whether a person will get cancer or not,’ said study lead author Professor Jamie Bernard from Michigan State University.
‘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.’
One in four adults in the UK are overweight or obese while one in three of adults living in the US are, according to government statistics.
How the research was carried out
The researchers fed mice a high-fat diet and induced the growth of cancer with ultraviolet B rays.
They then performed a lipectomy, a type of surgery that removes the layer of fat around the waist on the rodents.
Professor Bernard and his team analysed the cells and discovered that visceral fat produced a protein called fibroblast growth factor-2 (FGF2) in much larger amounts compared with subcutaneous fat.
Additionally, the scientists revealed that FGF2 drives skin and breast cells that were ‘already vulnerable to the protein’ to transform into cancerous cells.
They also took samples of visceral fat taken from women who had undergone a hysterectomy and found that when transplanted into mice, the tissue that had higher secretions of the FGF2 protein went on to form cancer tumors.
FORGET BMI: HIP-TO-HIP RATIO IS A BETTER INDICATOR OF HEALTH
Your hip-to-waist ratio is the best indicator of how healthy you are, a new study says.
Currently, the body mass index (BMI) is the most widely-used system by doctors to gauge whether or not a person is healthy, overweight or obese.
But researchers say your BMI is not only a bad indicator of how healthy you are, it can lead to doctors prescribing the wrong treatment for patients.
BMI first gained popularity in the 1970s as a way of judging body fat, based on your weight in relation to your height. A healthy BMI is typically measured between 18.5 and 24.9.
Anything under 18.5 is considered underweight. BMIs between 25 and 29.9 fall into overweight territory, and above 30 is considered obese.
Meanwhile, waist-to-hip ratio is calculated by dividing the circumference of your waist by that of your hips, found the joint study from Loughborough University in England and the University of Sydney in Australia.
Women with a ratio of 0.85 or more and men with a ratio of 0.9 or more indicates high levels of visceral fat, which is linked to cardiovascular disease, diabetes and stroke.
BMI is not the best tool
The study findings, published in the journal Oncogene, suggests the widely used body mass index (BMI) tool may not tell us much about our health risks.
BMI is controversial because it doesn’t actually take the amount of a person’s body fat into account, just their total body weight and their height.
‘Our study suggests that body mass index, or BMI, may not be the best indicator,’ says Professor Bernard.
‘It’s abdominal obesity, and even more specifically, levels of fibroblast growth factor-2 that may be a better indicator of the risk of cells becoming cancerous.’
The researchers note that obesity seems to be a factor in many types of cancer, including those that affect the breasts, colon, prostate, uterine system, and kidneys.
The study authors added that fat also increases estrogen, which is possibly implicated in increasing risk for some cancers.
Are you ‘over-fat’?
The study adds weight to recent research which found that up to 90 percent of adult males in developed countries are ‘over-fat,’ a new term that seems to have emerged overnight.
It is distinct from being ‘overweight’ the study argues, because there can be excess fat without one’s BMI being high enough to fall into this category on the BMI.
Published in the journal Frontiers in Public Health, the research on over-fatness also stressed excess fat stored in the abdomen region in particular is dangerous.
The team, led by Australian health expert Philip Maffetone, warned of abdominal fat’s link with ‘an increased risk of chronic disease (e.g, cancer, stroke, heart disease, Type 2 diabetes), higher levels of morbidity and mortality, and reduced quality of life’.
The good news is that visceral fat yields fairly easily to exercise and diet, according to an article on the Harvard Medical School website.
It stated that the benefits range ‘from lower blood pressure to more favorable cholesterol levels’.