That obesity had deleterious health consequences isn’t news, especially around here. Yet, we still find the results of a study out of Australia, published in Cancer Epidemiology Biomarkers and Prevention this week on weight gain and colon cancer risk compelling. Most adults experience weight gain over the course of their lives and this weight gain, even if your BMI remains within the “normal” range, can increase your risk of colon cancer. Bassett and colleagues found that each 5 kg (11 lbs) of weight gain in men significantly increased risk of colon cancer. Reports on the effects of weight gain for women are less consistent, and this report found no association.
Why might gender matter? Men and women tend to gain weight differently in adulthood. Men, in particular, tend to see a shift in body fat from the periphery to the trunk - that is, they put more weight around the middle - something called abdominal adiposity, or abdominal obesity if it gets bad enough. This central weight gain may be a stronger predictor than overall weight of cancer risk (along with other health outcomes). Abdominal obesity is associated with hyperinsulinemia, which likely plays a role in colon cancer risk. Men tend to accumulate more visceral fat.
Does this mean women are off the hook? Sadly, no – as regular CNiC readers have surely realized by now – “cancer” isn’t one disease with uniform risks. And weight gain increases risk of breast cancer in women as we’ve discussed before. So the findings on colon cancer are evidence that EVERYONE benefits from avoiding weight gain.
And since avoiding weight gain is easier than losing weight once you’ve gained it, watching weight gain is a good strategy for all of us.