Chronic constipation may be linked to cognitive decline, according to research presented at the Alzheimer’s Association International Conference in the Netherlands on July 19. Roughly 16 percent of the world’s population struggles with constipation, with older adults particularly prone to have irregular bowel movements.
[Related: Why your poop gets weird on vacation—and what to do about it.]
In this ongoing study, chronic constipation was defined as only having a bowel movement every three or more days. Chronic constipation correlated with a 73 percent higher risk of subjective cognitive decline and showed changes in gut microbiome. Cognitive function is an umbrella term for individual mental capacity for thinking, reasoning, learning, decision-making, problem-solving, paying attention, and remembering.
While chronic constipation has been linked with anxiety, depression, and inflammation, the Alzheimer’s Association says that there are still several unanswered questions about the connections between digestive health and cognitive function.
The team on this new study looked at over 112,000 adults who participated in the Nurses’ Health Study, Nurses’ Health Study II, and Health Professionals Follow-Up Study. The two Nurses’ studies are complete, and looked at the risk factors for major chronic diseases in North American women. The third study is ongoing and investigating this same topic in men.
This latest research on constipation used data on the frequency of participants’ bowel movements from 2012 to 2013, their self-assessments of cognitive function between 2014 to 2017, and some of the participants’ objectively measured cognitive function between 2014 and 2018.
The researchers found that constipated participants had significantly worse cognition compared with those who pooped once a day. The impairment was equivalent to three years or more of chronological cognitive aging. The authors also found an increased risk among those who pooped more than twice per day, but the higher odds were small.
“These results stress the importance of clinicians discussing gut health, especially constipation, with their older patients,” senior investigator Dong Wang from Harvard Medical School, Brigham and Women’s Hospital, and Harvard T.H. Chan School of Public Health said in a statement. “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.”
[Related: Baboon poop shows how chronic stress shortens lives.]
An unrelated study published in February in the journal Neurology found that those who regularly use laxatives may have an increased risk of developing dementia compared to those who don’t use laxatives.
“Finding ways to reduce a person’s risk of dementia by identifying risk factors that can be modified is crucial,” co-author Feng Sha from the Shenzhen Institute of Advanced Technology at the Chinese Academy of Sciences said in a statement in February. “More research is needed to further investigate the link our research found between laxatives and dementia. If our findings are confirmed, medical professionals could encourage people to treat constipation by making lifestyle changes such as drinking more water, increasing dietary fiber and adding more activity into their daily lives.”
Eating enough fiber from vegetables, fruits, whole grains and nuts can prevent constipation. The Food and Drug Administration recommends that total fiber intake should be at least 25 grams per day. Proper hydration can also soften stools, and exercising a few times per week can also help.
It is also important to understand the challenges and individual nature of understanding gut bacteria and the microbiome at large,
“Each person seems to have a unique microbiome, almost like a fingerprint,” gastroenterologist Monia Werlang from the University of South Carolina Greenville Medical School told NBC News. “Scientists are still learning how to manipulate it to promote health and to modify disease. Targeting the microbiome is promising, but there are many unknowns, especially considering the variability from person to person.”
