According to a study published in the recent online issue of Neurology people who regularly use laxatives, a common treatment for constipation, may have more than a 50% increased risk of developing dementia than people who do not use laxatives.
Researchers also found people who used only osmotic laxatives, a type of laxative that attracts water to the colon to soften stool, had an even greater risk.
Other types of laxatives are bulk-forming, stool-softening, and stimulating.
The study does not prove that laxatives cause dementia. It only shows an association.
“Constipation and laxative use are common among middle-aged and older adults,” said study author Feng Sha, PhD, of the Shenzhen Institute of Advanced Technology at the Chinese Academy of Sciences in Guangdong, China.
"However, regular laxative use may change the microbiome of the gut, possibly affecting nerve signaling from the gut to the brain or increasing the production of intestinal toxins that may affect the brain. Our research found regular use of over-the-counter laxatives was associated with a higher risk of dementia, particularly in people who used multiple laxative types or osmotic laxatives.”
Sha noted that osmotic and stimulant laxatives are not recommended for regular use, yet some people use them regularly.
The study involved 502,229 people in the UK biobank database with an average age of 57 who did not have dementia at the start of the study.
Of this group, 18,235 people, or 3.6%, reported regularly using over-the-counter laxatives. Regular use was defined as using a laxative most days of the week during the month before the study.
Over an average of 10 years, 218 of those who regularly used laxatives, or 1.3%, developed dementia. Of those who did not regularly use laxatives, 1,969 people, or 0.4%, developed dementia.
Link to read study here.