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.