Concerns About Benadryl and Dementia Risk

Each year, millions of Americans rely on Benadryl to ease allergy symptoms. However, recent findings from medical professionals have revealed a troubling connection between this common medication and a serious illness.

Benadryl contains diphenhydramine, a substance that effectively blocks histamine receptors. Histamine plays a role in inflammation, leading to symptoms like a runny nose and itchy skin.

What’s concerning, though, is that this medication can also cross the blood-brain barrier, interfering with acetylcholine receptors—crucial for functions like attention and memory.

A study indicated that regular use of Benadryl and similar drugs may increase the risk of dementia by 54% and Alzheimer’s by 63% compared to those who don’t use these medications at all.

Additional research has associated the drug with increased risks of drowsiness, falls, and even car accidents. In fact, there’s been guidance in Europe suggesting that individuals avoid driving after taking it.

Dr. Joao Lopes, a pediatrician at Case Western University, noted that multiple studies over the past decade highlight a link between Benadryl and dementia, particularly among older patients. He shared that it’s not usually the first choice due to the availability of safer alternatives.

Dr. Anna Wolfson, an allergist from Massachusetts General Hospital, added, “If you’re on a deserted island and Benadryl is your only option, then sure, take it. But in almost every other situation, there are safer, more effective alternatives.”

A spokesperson for Kenvue, the company behind Benadryl, maintained that no definitive studies prove a direct causal link between diphenhydramine use and dementia risk. They emphasized that the ingredient is considered safe and effective by health authorities in the U.S.

In a comprehensive study published in JAMA Internal Medicine, researchers tracked over 3,400 individuals aged 65 and older in Seattle. Notably, around 2,200 participants, or 64%, were using antihistamines, including diphenhydramine.

Participants had been recruited between 1996 and 2003, and initially, none had dementia. However, about a decade later, nearly 800 cases of dementia were documented, representing 23% of those involved in the study.

Those taking anticholinergic medications, like Benadryl or certain antidepressants, at least twice a week showed a 54% higher risk of developing dementia compared to those who didn’t use them.

This observational study did not definitively prove a connection between dementia and Benadryl. Still, it adds to a larger body of evidence suggesting a potential association.

While doctors agree that occasional use of the medication is generally safe, they advise discussing with a healthcare provider if taken more frequently—like two to three times per week.

Instead of Benadryl, newer antihistamines such as cetirizine (known as Zyrtec) or fexofenadine (commonly referred to as Allegra) are recommended by physicians.

Dr. Wolfson also mentioned, “Using Benadryl occasionally is perfectly fine; there’s no need to discard your supply.” Meanwhile, Dr. Olalekan Otulana, a physician based in the UK, pointed out that frequent use over months or years, especially in older adults, is of greater concern.

He added that occasional use—like for allergy attacks or sleep issues—is usually not a huge risk. It’s more about having an informed discussion with a doctor if you find yourself using it regularly.

Benadryl has been in use in the U.S. since the 1940s, with many individuals continuing its use simply due to familiarity, rooted in childhood experiences.

Interestingly, in some European nations, such as the UK, Benadryl does not include diphenhydramine, opting for newer, safer antihistamines instead. In Germany, Sweden, and other parts of Europe, access to first-generation antihistamines has even faced restrictions.

It remains unclear why Kenvue employs different ingredients in the U.S. compared to other countries. In the U.S., approximately 1.5 million prescriptions for diphenhydramine are issued annually, alongside countless over-the-counter sales.

Many healthcare professionals have been advocating for alternatives to Benadryl for quite some time. A recent paper highlighted that while diphenhydramine was once a groundbreaking antihistamine, it is now surpassed by second-generation options that offer similar benefits with fewer side effects.

Thus, they concluded that diphenhydramine may no longer be suitable for regular prescribing or easy access over the counter.