Obesity’s link to cancer has been a topic of discussion for a while now, especially regarding where the fat is located in the body. Recent findings indicate that, for men, a larger waistline is a more significant predictor of obesity-related cancers than body mass index (BMI). This insight is drawn from a study published in the Journal of the National Cancer Institute and will be showcased at the European Congress on Obesity in Spain.
Dr. Ming Sun, Dr. Josef Fritz, and Dr. Tanja Stocks from Lund University in Sweden spearheaded the research. They examined data from 340,000 Swedish participants, averaging 51 years old, whose BMI and waist measurements were recorded between 1981 and 2019. The study then cross-referenced this data with cancer records from the Swedish Cancer Register.
Over 14 years, the study identified 18,185 cases of obesity-related cancers among these individuals. For men, an increase in waist size by about 11 centimeters raised the risk of such cancers by 25%, surpassing the 19% risk associated with an increase in BMI. In contrast, for women, both a 12 cm increase in waist circumference and a rise in BMI were linked to a 13% higher cancer risk.
These obesity-related cancers cover a range of types, from esophagus and gastric cancers to breast (postmenopausal) and ovarian cancers. As the researchers noted, “BMI is a measure of body size, but does not provide information on fat distribution,” while waist circumference is more connected to abdominal fat. This difference is crucial since visceral fat, which surrounds abdominal organs, is metabolically active and associated with various health issues like insulin resistance.
The study points out that men and women store fat differently, which could explain the varying cancer risk factors. Men are more prone to accumulate visceral fat around their bellies, whereas women typically store more subcutaneous and peripheral fat. This distinction makes waist circumference a more telling measure for men.
Dr. Marc Siegel from NYU Langone Health, although not part of the study, highlighted that “belly fat contains a lot of the inflammatory chemicals that act as carcinogens.” He also mentioned that “obesity leads to inflammation,” correlating with several cancer types. For women, considering waist and hip circumference could provide a clearer picture of cancer risk, as suggested by the Swedish research.
Dr. Brett Osborn, a neurosurgeon and longevity expert, elaborated on these gender differences in fat storage. While women generally accumulate fat on their hips, thighs, and buttocks, men tend to store it in the abdomen. This visceral fat is not just passive; it actively secretes inflammatory chemicals, raising insulin levels and potentially fostering cancer growth.
Osborn emphasized the limitations of BMI, noting that it doesn’t account for muscle mass or fat distribution. Consequently, a muscular individual might be misclassified as overweight based solely on BMI. To mitigate cancer risk, Osborn recommends men keep a close eye on their waist measurements and consider using medical-grade tools to track visceral fat.
He stated, “Understand that belly fat isn’t just cosmetic — it’s carcinogenic,” and warned that a waist size over 40 inches should be a cause for concern. Strength training, performed regularly, can help reduce visceral fat and inflammation, offering a proactive approach to managing health risks.
