Two new studies in mice suggest that caffeine might have protective effects in the brains of Parkinson’s disease patients.

The studies, “Chronic Caffeine Treatment Modulates Disease Progression in a Transgenic Alpha-Synuclein Prion-Like Spreading Mouse Model of Parkinson’s Disease,” and “Chronic Caffeine Treatment Reverses A-Synuclein-Induced Cognitive Impairment With Enhanced Dendritic Spine Density and Morphology in Mice,” will be presented during the 14th​ International Conference on Alzheimer’s and Parkinson’s Diseases and related neurological disorders, March 26-31 in Lisbon, Portugal.

Previous epidemiological studies have suggested that consuming caffeine might protect against the development of Parkinson’s. These more-recent studies set out to test this premise more directly in an animal model.

Both studies used mouse models of Parkinson’s that involved injecting mice with alpha-synuclein. This protein is a major component of Lewy bodies, irregular “clumps” in brain cells that are a hallmark of Parkinson’s pathology. Specifically, both research teams used a mutant form of the protein called A53T, which forms these clumps even more effectively than the wild-type protein.

In both studies, injection with A53T led to changes characteristic of Parkinson’s disease, such as impaired motor function and memory, as well as changes in brain physiology, like the development of the aforementioned Lewy bodies and loss of dendritic spines (parts of neurons involved in making connections in the brain).

However, when the mice were given caffeine in their drinking water, these effects were lessened. Both studies showed similarly beneficial results, though the exact parameters that were measured were different.

In the first study, researchers at Aarhus University, Denmark, report that mice given caffeine had less alpha-synuclein in their brains. Caffeine also caused a three–week delay in the onset of clasping, which is a behavior mice do with their hind limbs that is indicative of brain damage. Furthermore, caffeine-treated mice lived, on average, 40% longer than their counterparts who weren’t given caffeine.

In the second study, researchers at Wenzhou Medical University, China, reported that mice given caffeine had fewer memory problems and more dendritic spines than their untreated counterparts.

Both studies support the previous epidemiological evidence that caffeine can be protective for Parkinson’s disease, although there is the usual caveat that experiments in animal models are never a perfect replica of actual human disease.

It also is not clear why or how caffeine might have such protective effects, and further research will be needed to figure out just how caffeine might benefit Parkinson’s patients.