If you're a coffee drinker, you might also be protecting your brain from Alzheimer's disease, a new study in mice suggests.
Something in coffee -- though researchers have yet to determine what exactly that "something" is -- interacts with caffeine, boosting levels of a growth factor called granulocyte colony stimulating factor (GCSF) that appears to fight off Alzheimer's disease in mice, according to the study that will be published next week in the Journal of Alzheimer's Disease.
Previous studies in humans have suggested that drinking coffee or another caffeinated beverage every day in middle and older age seems to decrease the risk of Alzheimer's disease. University of South Florida researchers, who conducted the new study, thought that it was the caffeine that had the beneficial effects.
But their new mouse study shows that it could also be something else in coffee that interacts with caffeine to protect the brain, since only caffeinated coffee -- not decaffeinated coffee, nor caffeine alone -- improved the mice's memory and increased GCSF levels, the study said. High blood levels of GCSF was also linked with better memory in the mice.
The human equivalent of four to five cups of coffee a day seemed to produce the beneficial brain effect, the study said. However, researchers only used "drip" coffee in the study, so it's unknown whether instant coffee has the same effects.
"Caffeinated coffee provides a natural increase in blood GCSF levels," study researcher Dr. Chuanhai Cao, a neuroscientist at the University of South Florida, said in a statement. "The exact way that this occurs is not understood. There is a synergistic interaction between caffeine and some mystery component of coffee that provides this beneficial increase in blood GCSF levels."
Researchers said GCSF likely has this effect because it causes stem cells in the bone marrow to come into the brain and remove the beta-amyloid plaques associated with Alzheimer's disease. It also has a role in forming brain cell connections and creating new brain neurons, they said.
Coffee is known to have other beneficial health effects, including reducing prostate cancer risk, according to a study out of Harvard last month. It's also been shown to protect against Type 2 diabetes, liver cancer and Parkinson's disease, according to the Mayo Clinic.