New Study Links Late-Night Eating to Higher Colorectal Cancer Risk

In a recent study, researchers from Rush University Medical College in Chicago found compelling evidence suggesting that eating late at night, particularly within three hours of bedtime, may significantly increase the risk of developing colorectal cancer.

The study reinforced long-standing advice from experts to avoid late-night meals, especially those high in fats and sugars.

Research has found that eating close to bedtime may disrupt the body's internal clock, or "circadian rhythm." Unlike the central circadian rhythm regulated by the brain's release of melatonin to induce sleep, late-night eating appears to affect the "peripheral circadian rhythm." This peripheral system governs how various parts of the body adjust their functions in response to the transition from day to night. Disruption of this rhythm could potentially contribute to the increased risk of adenoma formation and, subsequently, colorectal cancer.

An adenoma is a small, noncancerous lesion that can potentially turn cancerous over time, with an estimated 5% to 10% undergoing malignant transformation. The risk associated with adenomas varies depending on their size and location within the gastrointestinal tract.

The research team conducted a survey involving 664 individuals undergoing colonoscopy screenings for cancer. Remarkably, 42% of the participants reported being late-night eaters. The findings revealed that this group was 46% more likely to have an adenoma detected during their colonoscopy compared to those who did not eat late at night.

"It is true that eating later at night can disrupt your circadian rhythm. In addition, many of my patients have told me that when they do eat later at night, they don't always make the healthiest food choices. Their late-night food choices are generally higher in added sugar and fat. This may cause them to consume far more calories than their body needs. So, eating late at night can also lead to unwanted weight gain. So, if your late-night eating consists of foods high in sugar and fat, you may be negatively impacting your microbiome,” said Amy Bragagnini, spokesperson for The Academy of Nutrition and Dietetics.

The study emphasized the importance of aligning meal times with the body's natural rhythms to maintain overall health and reduce cancer risk. As the evidence continues to grow, the advice to avoid late-night eating becomes even more compelling, offering another reason to heed expert dietary recommendations.

Reference: Digestive Disease Week conference, Washington, DC, May 18-21, 2024; Edena Khoshaba, medical student Rush University Medical College Chicago; Amy Bragagnini, MS, RD, CSO, spokesperson, Academy of Nutrition and Dietetics.