Medicines can make a huge difference for people living with common health problems, from allergies and bladder symptoms to depression and Parkinson’s disease.
But some medicines can also affect the brain, especially in older adults. Research suggests that certain drugs with anticholinergic effects may be linked to a greater risk of future problems with memory and thinking.
Anticholinergic medicines reduce the activity of acetylcholine, a chemical messenger that helps nerve cells communicate. Acetylcholine plays an important role in memory, attention, muscle activity, and many automatic functions in the body.
Blocking it can be useful for treating some medical conditions, but researchers have long wondered whether repeated exposure could affect brain health.
A research team from the University of California, San Diego studied 688 older adults who had no problems with memory or thinking when the research began. Their average age was about 74. The participants received yearly tests of their memory and thinking abilities for as long as 10 years.
Researchers also recorded the medicines the participants regularly used. Regular use was defined as taking a medicine at least once a week for more than six months. About one-third of the participants were taking at least one medicine considered to have anticholinergic effects.
The results showed a concerning pattern. Older adults taking at least one of these medicines had a 47% greater risk of developing mild cognitive impairment than people who were not taking them. Mild cognitive impairment involves noticeable problems with memory or thinking that are greater than expected with normal aging but are not severe enough to be dementia.
The association appeared even stronger in people who were already more vulnerable to Alzheimer’s disease. Participants with biological signs associated with Alzheimer’s who also used anticholinergic medicines were about four times more likely to develop mild cognitive impairment than people without those risk factors who were not taking the medicines.
Genetics also appeared to matter. People carrying genetic changes associated with a higher risk of Alzheimer’s disease were about 2.5 times more likely to develop mild cognitive impairment if they were taking anticholinergic medicines. This suggests that the effects of these drugs may not be the same for everyone.
The findings do not prove that the medicines directly caused the memory problems. People who need certain medications may have other health conditions that influence their risk, and observational studies cannot completely separate all of these factors. Still, the results add to concerns about the total medication burden faced by many older adults.
The research also does not mean people should suddenly stop taking prescribed medicines. Abruptly stopping some drugs can be dangerous, and the benefits of treatment may be greater than the possible risks. Anyone concerned about memory effects should instead ask a doctor or pharmacist to review all prescription and over-the-counter medicines they regularly use.
A medication review can be particularly useful for older people who take several drugs. Doctors may sometimes be able to lower a dose, replace a medicine with another option, or remove a drug that is no longer needed. The safest choice depends on the person’s health conditions, symptoms, and other treatments.
The study was led by researchers including Lisa Delano-Wood and was published in Neurology, the medical journal of the American Academy of Neurology. The findings suggest that carefully reviewing medicines with anticholinergic effects could be one practical way to help protect cognitive health as people grow older.
If you care about brain health, please read studies about vitamin D deficiency linked to Alzheimer’s and vascular dementia, and higher magnesium intake could help benefit brain health.
For more information about brain health, please see recent studies about antioxidants that could help reduce dementia risk, and coconut oil could help improve cognitive function in Alzheimer’s.
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