Researchers say they have found a possible link between regular laxative use and a person’s risk of dementia, but experts note that the research is very early and should be interpreted with caution.
According to the researchers, from medical institutions across China as well as the University of Cambridge and Harvard Medical School, constipation affects about 20% of the general population and about 70% of people in nursing homes, and most people with constipation are treated with one of two versions of over-the-counter laxatives.
The study, published Wednesday in the American Academy of Neurology’s medical journal Neurology, suggests a potential link to dementia is strongest with osmotic laxatives, which draw water into the stool to make it more softer and easier to evacuate. The other major type, stimulant laxatives, increase muscle contractions along the stool mass.
The study included around 10 years of self-reported data from 476,219 adults aged 40-69 in the UK. At the outset, study authors identified participants’ health status and lifestyle factors, including their exposure to over-the-counter laxatives. About 3.6% of participants said they had used laxatives almost every day of the week in the previous four weeks.
These regular users were more likely to be female, to be less educated, to have a chronic disease, and to take anticholinergics and opioids regularly. “The prevalence of stroke, high blood pressure, depression, poor global self-health rating, and intake of calcium channel blockers, statins, and steroids was higher among users regular users than in non-regular users,” the study said.
Researchers found that 2,187 participants had been diagnosed with dementia from all causes, which includes Alzheimer’s disease and vascular dementia, by the end of the study period.
“Regular laxative use was associated with a higher risk of all-cause dementia, particularly among those who used multiple types of laxatives or osmotic laxatives,” they wrote in the study.
Dementia was diagnosed in 1.3% of participants who regularly used laxatives and 0.4% of those who did not report regular laxative use.
Dr. Richard Isaacson, a preventive neurologist at the Florida Institute for Neurodegenerative Diseases, says the results are interesting but only speculative.
“Further study is absolutely warranted to have a definitive impact on clinical practice,” said Isaacson, who was not involved in the study.
The researchers have offered an explanation for the discovery, which begins with the makeup of the microbiome, the trillions of microorganisms that live in the gut.
They said an osmotic laxative has a long-lasting impact on the microbiome and could affect the production of neurotransmitters needed for normal cognitive function. An osmotic laxative can also increase the production of intestinal toxins, they wrote.
Laxatives can also disrupt the epithelial barrier, which regulates nutrient absorption and helps deliver needed substances to the central nervous system.
Limitations of the study include that patient data was self-reported and could have been scored inaccurately, and that there was little information about possible confounders like fiber intake and severity of constipation.
Dr. Ali Rezaie, director of the gastrointestinal motility program at Cedars-Sinai Medical Center, said he was skeptical of the results and that the study lacked a primary component needed to accurately establish an association between the regular laxative use and dementia: enough evidence.
“Laxatives change the microbiome, but we don’t have data to suggest that these changes caused by laxatives are the same as what we see in the dementia study,” said Rezaie, who did not participate. looking. “It’s a big leap that will take decades of study to understand.”
He says the study period wasn’t long enough to derive concrete evidence, and the core data from participants doesn’t accurately represent what he sees in his practice.
The study equates the number of participants who regularly used laxatives with the number of people with constipation, but the two groups do not always overlap.
“How come the prevalence of constipation in their study was only 3%? ” He asked. “It just tells me that they didn’t pick up all the constipated patients, they only picked up the patients who mentioned over-the-counter laxatives that they were taking regularly. … It’s very unusual to find only 3% of a constipated population.
Isaacson also noted the lack of participant data, particularly due to the diversity of participants.
“From a health equity perspective, it’s important to say that the specific study population was 90% white,” he said. “Broader conclusions based on a more diverse population really have to be held.”
Isaacson and Rezaie came to a similar conclusion: more research is needed, and the potential link is not strong enough to change medical practice.
“We don’t really want to tell people it’s time to stop their laxative because you’re going to get dementia. That’s the wrong message,” Isaacson said.
Rezaie said he worries his patients are overly concerned about the possibility of dementia and avoid the laxatives needed for certain procedures.
“It might even affect our colon cancer screening,” he said.