Young men who are obese in their late teens may have double the risk of developing colorectal cancer in middle age, suggests a new study published in the journal Gut.
An indicator of inflammation - erythrocyte sedimentation rate (ESR) - in late adolescence also linked to an increased risk of this cancer, the study found.
The study included almost 240,000 Swedish men who had undergone compulsory military exams when they were between the ages of 16 and 20. At that time, almost 8 of the 10 young men had a BMI in the healthy range. Some 5% were moderately overweight; 1.5% were very overweight; and 1% were obese.
Over an average of 35 years, 885 of the men developed colorectal cancers.
Compared with the young men whose weight was within the normal range, those who were categorized by their BMIs as on the high end of overweight and obese were over twice as likely to develop colorectal cancer. Overweight (BMI of 27.5 to 30) linked to a twofold higher risk; Obesity with a 2.38 higher risk.
Among men without known inflammatory bowel disease at the time of their health check, those with a high ESR of had a 63% higher risk of colorectal cancer than those with a low ESR. The findings of overweight and ESR were independent of each other, indicating that teen BMI may influence colorectal cancer risk through mechanisms other than inflammation as measured by ESR, they say. ESR also may not generalize to other indicators of inflammation, such as the commonly-studied CRP. (Inflammation can lead to red blood cells clumping and the more clumping, the denser they are. The ESR measures the rate at which red blood cells fall in a tube in a set period of time, indicating more inflammation.)
The study could not account for adult BMI and inflammation markers, which are known to increase risk of this cancer. It also did not look at childhood BMI; children who are heavier are more likely to grow into adults who are heavier. Yet this adds to the research on the role of life course and later cancer risk. For example, a study highlighted in last month's CRU suggested overweight girls had increased risk of adult colorectal cancer.
Study authors were supported by the National Cancer Institute and the Rose Traveling Fellowship from the Harvard School of Public Health; Örebro University Strategic Funding, and the cohort was developed with support from the UK Economic and Social Research Council (ESRC) as grants to the International Centre for Life Course Studies.
Source: Elizabeth D Kantor, Ruzan Udumyan, Lisa B Signorello, Edward L Giovannucci, Scott Montgomery, Katja Fall. Adolescent body mass index and erythrocyte sedimentation rate in relation to colorectal cancer risk. Gut Published Online First: 18 May 2015,
Published on May 27, 2015