Overweight and inflammation during adolescence may increase colorectal cancer risk later in life

Being very overweight in your teens doubles the risk of developing colorectal cancer later in life compared to those whose weight was within the normal range a new Swedish study suggests. The research team behind the study are from örebro University in Sweden and Harvard School of Public Health in the US.

- A measure of inflammation, elevated erythrocyte sedimentation rate - or ESR for short -at this age may also be linked to an increased risk of bowel cancer, says researcher Katja Fall at örebro University.

It has previously been established that adult obesity and inflammation is associated with an increased risk of bowel cancer, but this new large-scale study indicates that being very overweight as a teen is also influential to developing the disease later in life. The findings are published in Gut, which is an international journal for research in gastroenterology.

The researchers studied 240,000 Swedish men who had health checks in connection with their conscription into the army between 1969 and 1976. At the enlistment assessment, health data including weight, height and ESR were recorded. The National Cancer Register enabled the researchers to identify those men diagnosed with bowel cancer later in life.

During the monitoring period, which spanned 35 years, 885 men were diagnosed with bowel cancer, 384 of whom with rectal cancer.

Preventive measures

- Our findings show that the men who were very overweight in late adolescence were twice as likely to develop bowel cancer later in life compared to those whose weight was within the normal range. In addition, for the men whose blood sample showed signs of inflammation at enlistment, there was also an increased risk of developing bowel cancer, says Katja Fall.

These findings suggest that both a high BMI (Body Mass Index) and inflammation during adolescence may have a role in the development of bowel cancer. Both factors were, however, independent of each other, indicating that teen overweight may influence bowel cancer risk through mechanisms other than inflammation.

- Further studies are needed to better understand the role of weight and early-life inflammation in the development of bowel cancer. A better understanding would give us opportunities to enhance prevention against cancer development at an early stage, says Katja Fall.