Published in Journal of the National Cancer Institute Spectrum, lead by Dr. Kathryn Hughes Barry from the University of Maryland School of Medicine, researchers utilizing data from the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening Trial, a large, multi-center cancer risk study, found that weight loss lead to a 46% reduction in colon cancer risk.

The PLCO study followed 154,942 men and women between the ages of 55 to 74 from 1993-2001. Per researchers’ inclusion criteria, they reviewed approximately 18,000 participants who were screened for colon cancer with a sigmoidoscopy and who’s weight were followed through the years.

The researchers found that losing weight from early to late adulthood of about 2 pound per decade, decreased the risk of developing adenoma (a pre-cancerous lesion) by 46%. The greatest benefits came from people who were already obese and overweight in their 20’s, where their weight loss led to a risk reduction by 60%.

The authors also found that a 6 pounds or more weight gain every five years lead to a 30% increased risk of adenoma development.

In addition, for unknown reasons, benefits of weight loss for men were greater than women. One hypothesis was that men have a higher proportion of mid-abdominal weight.

Colon cancer remains on the rise, especially in young people. Despite what entertainment media makes it out to be, obesity and being fat is more than an image issue, it’s a health problem. Instead of blaming people for making them feel bad about being fat, people should focus on how they want to improve their health and want better for themselves. Even more important isn’t just the obesity, but the behaviors and mindset that leads to obesity.

S He et al. Weight change and incident distal colorectal adenoma risk in the PLCO Cancer Screening Trial. JNCI Cancer Spectrum. https://doi.org/10.1093/jncics/pkab098