Over the years, many studies have portrayed various health benefits of drinking coffee. Some even connect improved brain function with coffee.

However, new research links coffee and Alzheimer’s in a negative way. The study suggests that long-term caffeine consumption may result in worsening Alzheimer’s symptoms.

Researchers at the Universitat Autònoma de Barcelona in Spain observed mice with Alzheimer’s. They found that prolonged exposure to caffeine increased behavioral symptoms of Alzheimer’s.

Most people associate memory loss as the main symptom of Alzheimer’s, but others present themselves as well. Some examples include delusions, hallucinations, irritability, anxiety and depression.

“The mice develop Alzheimer’s disease in a very close manner to the human patients with early-onset form of the disease,” said first author Raquel Baeta-Corral, of the Universitat Autònoma de Barcelona. “They not only exhibit the typical cognitive problems, but also a number of [behavioral and psychological symptoms of dementia], so it is a valuable model to address whether the benefits of caffeine will be able to compensate its putative negative effects.”

To explore this, the researchers added caffeine to the mice’s drinking water, equivalent to five cups of coffee per day for humans. After a set period of time, the mice participated in experiments to display their cognitive and behavioral Alzheimer’s symptoms.

The mice that drank caffeinated water experienced greater behavioral and psychological symptoms of dementia than those drinking regular water. What’s more, caffeine didn’t do much to boost learning and memory in the mice.

With such results, coffee and Alzheimer’s may not be the best combination.

“We speculate that over a chronic treatment with caffeine, the exacerbation of anxiety-like [behavioral and psychological symptoms of dementia] may partially interfere with the beneficial cognitive effects to the extent that they can be in the opposite direction,” the researchers said.