A new study published in JAMA Oncology suggests that excess weight over a lifetime appears to play a greater role in an individual’s risk for colorectal cancer (CRC) than what was previously believed.

A population-based, case-control study evaluated the association between cumulative lifetime excess weight and the risk of colorectal cancer (CRC). Investigators assessed the height and self-reported weight recorded in 10-year increments, beginning at 20 years of age up to the current age. The study included 5,635 people with CRC and 4,515 people in a control group. There was a considerable increase in the likelihood of CRC over the decades when people had excess weight long term compared with people who were in the normal weight range during the period. There was an association between the weighted number of years lived with overweight or obesity (WYOs) and the risk for CRC, with adjusted odds ratios (ORs) rising from 1.25 (95% confidence interval [CI], 1.09-1.44) to 2.54 (95% CI, 2.24-2.89) from the first to the fourth quartile of WYOs, in comparison with individuals who remained within normal weight range. The odds increased considerably the longer the time carrying the excess weight. Each SD increase in WYOs was tied to an increase in CRC risk by 55% (adjusted OR, 1.55; 95% CI, 1.46-1.64)… (Medscape, March 18; JAMA Oncology, March 17, 2022)