Obesity is a well-known risk factor for cancer, especially when it accumulates in specific body areas.
Recently, a new study suggests that for obesity-related cancers, a larger waist circumference poses a higher risk than body mass index (BMI), but only in men, not in women.
The research, published in the Journal of the National Cancer Institute and presented at the European Congress on Obesity in Malaga, Spain, is led by Dr. Ming Sun, Dr. Josef Fritz, and Dr. Tanja Stocks from Lund University in Sweden.
New research suggests that a larger waist circumference is a bigger risk factor than body mass index for obesity-related cancers — but only for men, not for women. (iStock)
The study analyzed data from 340,000 Swedish individuals with an average age of 51, whose BMI and waist measurements were recorded between 1981 and 2019. They compared this data with cancer diagnoses from the Swedish Cancer Register.
Over 14 years, the study found 18,185 diagnoses of obesity-related cancers among the participants.
In men, an 11 cm increase in waist circumference resulted in a 25% higher risk of obesity-related cancer, a greater risk factor than an increased BMI which raised the chances by 19%.
For men, an increase in waist circumference of around 11 cm resulted in a 25% higher risk of obesity-related cancer. (iStock)
In women, a 12 cm increase in waist circumference and an increase in BMI were both associated with a 13% higher cancer risk.
The release states that obesity-related cancers include cancers of various organs like the oesophagus, stomach, colon, liver, breast, endometrium, ovary, kidney, and thyroid.
“BMI is a measure of body size, but does not provide information on fat distribution, whereas waist circumference is a proxy more closely related to abdominal adiposity.”
The study suggests that waist circumference is a better predictor of cancer risk compared to BMI overall.
“BMI is a measure of body size, but does not provide information on fat distribution, whereas waist circumference is a proxy more closely related to abdominal adiposity,” the researchers explained.
“This difference is vital because visceral fat around the abdominal organs is more metabolically active and has been linked to various adverse health outcomes. Hence, the location of fat distribution can play a significant role in cancer risk.”
Why the gender difference?
The researchers propose that the reason for the gender gap may lie in where fat is stored in the body. Men tend to accumulate fat centrally around the abdomen, while women store fat in different areas like subcutaneously and peripherally.
The researchers suggested that combining hip circumference with waist circumference in women could give a more accurate estimation of visceral fat. (iStock)
The accumulation of excess body fat was noted to lead to higher insulin levels in men than in women, which could contribute to the stronger link between waist circumference and cancer risk in men.
“The divergence in how waist circumference and BMI relate to cancer risk between men and women underscores the complexity of the impact of excess body fat on cancer development,” the researchers stated.
“It suggests that considering biological and physiological differences between the sexes might be helpful in assessing cancer risk. Further research is needed to explore these sex differences.”
The researchers also recommended combining hip circumference with waist circumference as it could provide a more precise estimate of visceral fat in women.
“Waist circumference is a more accurate measure of visceral fat in men than in women,” the researchers wrote. (iStock)
Strength training three times per week is ideal, one doctor advised, adding, “Resistance training reduces visceral fat and inflammation.” (iStock)
Dr. Marc Siegel, clinical professor of medicine at NYU Langone Health and Fox News senior medical analyst, who was not part of the study, emphasized that BMI is useful but not the only indicator of obesity.
“Belly fat contains a lot of the inflammatory chemicals that act as carcinogens.”
“Obesity causes inflammation, which is linked to various types of cancer, including breast, prostate, and gastrointestinal tract cancers,” he said.
“It’s not surprising that measuring waist circumference accurately could indicate a higher risk in men, as belly fat is known to contain inflammatory chemicals that can lead to cancer,” Dr. Siegel added.
