Your Weight & Cancer Risk

1 min

Investigators from Norway’s University of Bergen reviewed data on the weight of 220,000 adults from Norway, Sweden and Austria and followed these individuals for an average of 18 years to find out how much being overweight or obese affects the risk of developing different types of cancer. They reported that women who were overweight before the age of 40 had a 70 percent increased risk of endometrial (uterine) cancer. Men who were overweight before age 40 had a 58 percent increased risk for renal cell (kidney) cancer and a 29 percent increased risk for colon cancer. And regardless of gender, being overweight or obese before age 40 increased the risk of all these cancers by 15 percent. Those who were obese with a body mass index (a rough measure of body fat based on height and weight) over 30 had the highest risk of developing an obesity-related cancer compared to study participants with a normal BMI.

My take? No one knows exactly why obesity affects cancer risks. Excess body fat may influence the levels of several different hormones. These may include sex hormones such as estrogen associated with breast and uterine cancer, or hormones that regulate metabolism, such as insulin. For example, too much body fat around the waist is associated with insulin resistance, which has been linked to an increased risk of colon cancer.

Source:
Tone Bjørge et al, “BMI and weight changes and risk of obesity-related cancers: a pooled European cohort study.” International Journal of Epidemiology, 2019; DOI: 10.1093/ije/dyz188

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