That morning cup of joe may be just what you need to help jumpstart your workday and sharpen your mind. But if you find yourself repeatedly heading over to the coffee pot for refills, you may be actually putting your brain health at risk. Too much coffee can increase the risk of dementia, warns a new study.

Drinking six or more cups a day was linked with a 53 percent increased risk of dementia and make stroke more likely, too. Brain imaging reveals that drinking a lot of coffee was also associated with brain shrinkage, say scientists.

The study, conducted at the Australian Centre for Precision Health at the South Australian Health and Medical Research Institute, is the largest of its kind based on 17,702 participants aged 30 to 37. Kitty Pham, a PhD candidate at the University of South Australia, who led the team of international researchers, says the findings draw attention to the risk of over-consuming.

“Coffee is among the most popular drinks in the world. Yet with global consumption being more than nine billion kilograms a year, it’s critical that we understand any potential health implications,” she explains in a statement. “This is the most extensive investigation into the connections between coffee, brain volume measurements, the risks of dementia, and the risks of stroke – it’s also the largest study to consider volumetric brain imaging data and a wide range of confounding factors.

“Accounting for all possible permutations, we consistently found that higher coffee consumption was significantly associated with reduced brain volume,” she continues. “Essentially, drinking more than six cups of coffee a day may be putting you at risk of brain diseases such as dementia and stroke.”

‘Drink Water alongside that Cup of Coffee,’ Researchers Suggest

Dementia is a degenerative brain condition that affects memory, thinking, behavior and the ability to perform everyday tasks. About 50 million people are diagnosed with the condition worldwide. According to the Centers for Disease Control and Prevention, about 5 million senior Americans suffer from dementia. That figure is expected to balloon to 14 million by 2060, the agency predicts.

“This research provides vital insights about heavy coffee consumption and brain health, but as with many things in life, moderation is the key,” says senior investigator Elina Hyppönen, director of Australian Centre for Precision Health. “Together with other genetic evidence and a randomized controlled trial, these data strongly suggest that high coffee consumption can adversely affect brain health. While the exact mechanisms are not known, one simple thing we can do is to keep hydrated and remember to drink a bit of water alongside that cup of coffee.

“Typical daily coffee consumption is somewhere between one and two standard cups of coffee. Of course, while unit measures can vary, a couple of cups of coffee a day is generally fine,” she adds. “However, if you’re finding that your coffee consumption is heading up toward more than six cups a day, it’s about time you rethink your next drink.”