The Bittersweet Truth About Caffeine and Parkinson’s Disease

For years, we’ve been told that our beloved morning cup of joe might be doing more than just giving us a much-needed energy boost—it could also be protecting our brains from the devastating effects of Parkinson’s disease.

Indeed, numerous studies have suggested that people who consume higher amounts of caffeine are less likely to develop this progressive neurodegenerative disorder, which affects millions worldwide.

But what about those who have already been diagnosed with Parkinson’s? Can caffeine help slow the relentless march of this disease and improve their symptoms?

A new study set out to answer this very question…

The study, published in the journal Annals of Neurology, recruited 163 people with early Parkinson’s disease and 40 healthy controls. Each participant underwent a specialized brain scan called a single photon emission computed tomography (SPECT) scan, which assesses the activity of dopaminergic neurons—the very cells that are progressively lost in Parkinson’s.

Researchers also recorded each participant’s caffeine intake and other clinical measures. After an average of 6.1 years, 44 of these participants were re-examined.

To their surprise, the scientists found that people with high coffee consumption had 8.3–15.4% lower dopamine transporter binding in their striatal regions compared with low coffee consumers. In other words, those who drank more coffee had reduced dopaminergic activity, which is typically associated with more advanced stages of Parkinson’s.

Furthermore, caffeine consumption was linked to a progressive decline in dopamine binding over time.

However, despite these changes in brain function, the symptoms of the high-caffeine group were not measurably worse than those of the low-caffeine group.

These findings were unexpected, as the researchers had hypothesized that higher caffeine intake would be associated with increased dopamine transporter binding and less severe motor symptoms over time.

What could explain these counterintuitive results?

One possibility is that caffeine may have neuroprotective effects that are independent of its impact on dopaminergic neurons.

For example, caffeine is known to have anti-inflammatory properties and may interact with other neurotransmitters and cellular processes that could help preserve brain function in Parkinson’s.

Another intriguing finding from the study was that consuming caffeine just before the SPECT scan appeared to influence the results. This suggests that patients may need to be advised to avoid caffeine in the hours leading up to their brain scans to ensure the most accurate assessment of their disease progression.

While this study may dash hopes of using caffeine as a treatment to slow Parkinson’s progression, it’s important to remember that the research on caffeine and Parkinson’s risk is still compelling.

By continuing to study the complex relationship between this beloved stimulant and brain health, scientists may yet uncover new strategies for preventing or treating this devastating disease.

In the meantime, if you’re a coffee lover, there’s no need to feel guilty about savoring your daily brew—just remember that moderation is key, and always follow your doctor’s advice when it comes to managing your health.

To unraveling the mysteries of the brain, one cup at a time,

Rachel Mace
Managing Editorial Director, e-Alert
with contributions from the research team

P.S. Click here to read the latest “buzz” about caffeine…

Sources:

Kaasinen, V., Vahlberg, T., Soleimani, R., & Joutsa, J. (2023). Caffeine consumption, dopamine transporter binding, and progression of Parkinson’s disease. Annals of Neurology. https://doi.org/10.1002/ana.26716