WASHINGTON — , according to the results of research presented at the annual Digestive Disease Week® (DDW).
Investigators in a new study questioned 664 people getting a colonoscopy to screen for cancer, and 42% said they were late eaters. This group was 46% more likely than non–late eaters to have an adenoma found during colonoscopy. An estimated 5% to 10% of them become cancerous over time.
“A lot of other studies are about what we eat but not when we eat,” said Edena Khoshaba, lead investigator and a medical student at Rush University Medical College in Chicago. “The common advice includes not eating red meat, eating more fruits and vegetables — which is great, of course — but we wanted to see if the timing affects us at all.”
Ms. Khoshaba and colleagues found it did. Late eaters were 5.5 times more likely to have three or more tubular adenomas compared to non–late eaters, even after adjusting for what people were eating. Tubular adenomas are the most common type of polyp found in the colon.
So, what’s the possible connection between late eating and the risk for colorectal cancer?
Resetting Your Internal Clock
Eating close to bedtime could be throwing off the body’s circadian rhythm. But in this case, it’s not the central circadian center located in the brain — the one that releases melatonin. Instead, late eating could disrupt the peripheral circadian rhythm, part of which is found in the GI tract. For example, if a person is eating late at night, the brain thinks it is nighttime while the gut thinks it is daytime, Ms. Khoshaba said in an interview.
This is an interesting study, said Amy Bragagnini, MS, RD, spokesperson for the Academy of Nutrition and Dietetics, when asked to comment on the research. “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,” Ms. Bragagnini said. “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.
An unanswered question is if late eating is connected in any way at all to increasing rates of colorectal cancer seen in younger patients.
This was an observational study, and another possible limitation, Ms. Khoshaba said, is that people were asked to recall their diets over 24 hours, which may not always be accurate.
Some of the organisms in the gut have their own internal clocks that follow a daily rhythm, and what someone eat determines how many different kinds of these organisms are active, Ms. Bragagnini said.
“So, if your late-night eating consists of foods high in sugar and fat, you may be negatively impacting your microbiome.” she said.
The next step for Ms. Khoshaba and colleagues is a study examining the peripheral circadian rhythm, changes in the gut microbiome, and the risk for developing metabolic syndrome. Ms. Khoshaba and Ms. Bragagnini had no relevant disclosures.
A version of this article appeared on Medscape.com.