In a press release from July 19, 2023, the Alzheimer's Association International Conference (AAIC) presented findings from new research showing that chronic constipation—having one bowel movement every three or more days—is associated with cognitive decline. The findings were presented by Chaoran Ma, M.D., Ph.D., former research fellow at Brigham and Women's Hospital and Harvard Medical School and current Assistant Professor at University of Massachusetts Amherst at the AAIC, this week in Amsterdam. Ma and colleagues used data collected from more than 110,000 people in three cohort studies to explore the relationship between bowel movement frequency and cognitive function. AAIC explains their findings:
The researchers found that less frequent bowel movements were associated with poorer cognitive function. Compared to those with bowel movements once daily, constipated participants (bowel movements every three days or more) had significantly worse cognition, equivalent to 3.0 years more of chronological cognitive aging. Bowel movement frequency of every three days or less was associated with 73% higher odds of subjective cognitive decline. They also found:
- A slightly increased risk of cognitive decline in those who had bowel movements more than twice a day.
- Study participants with certain specific levels of microbes in the gut — fewer bacteria that can produce butyrate and fewer bacteria responsible for digesting dietary fibers — had both less frequent bowel movements and worse cognitive function.
The AAIC points out, importantly, that the prevalence of chronic constipation is higher among older adults than younger adults, and points to factors such as older adults eating lower-fiber diets, not engaging in as much exercise as they once might have, and using more medications that cause constipation. Not all of these factors can be drastically changed, but this research might encourage doctors and patients to consider making adjustments focused on diet, exercise, and gut health, if possible. Again, AAIC:
"These results stress the importance of clinicians discussing gut health, especially constipation, with their older patients," said senior investigator of this study, Dong Wang, M.D., Sc.D., an assistant professor at Harvard Medical School, Brigham and Women's Hospital and Harvard T.H. Chan School of Public Health. "Interventions for preventing constipation and improving gut health include adopting healthy diets enriched with high-fiber and high-polyphenol foods such as fruits, vegetables and whole grains; taking fiber supplementation; drinking plenty of water every day; and having regular physical activity."
Read more about the study here.