Parkinson’s disease is a progressive neurodegenerative disease that typically affects adults over 65 years old. Researchers recently investigated if caffeine and caffeine metabolites can be used as biomarkers to effectively diagnose Parkinson’s disease.
Parkinson’s disease is a neurodegenerative disorder that progressively leads to loss of bodily movement. Currently, it is estimated that 55,000 Canadians (0.2% of the Canadian population) are living with Parkinson’s disease, making it the second most common neurodegenerative disease in Canada. Though the cause of Parkinson’s disease remains unknown, research suggests that the degeneration of dopamine-releasing neurons is linked with movement loss and body tremors.
Early Parkinson’s symptoms typically manifest at around 64 years old, with a follow-up diagnosis about two years later. There are no universal specific tests available to physicians to diagnose Parkinson’s, which is partially why onset to diagnosis is drawn out. Additionally, since Parkinson’s disease typically affects patients over 65 years old, physicians are more likely to diagnose younger Parkinson’s patients significantly later compared to older patients which delay critical treatment and support programs.
Does Caffeine Protect Against Parkinson’s?
Previous research showed that caffeine consumption is associated with a lower risk of Parkinson’s, suggesting that caffeine may have a neuroprotective effect against Parkinson’s disease and that caffeine may be metabolized differently in Parkinson’s patients. Caffeine is primarily metabolized within our bodies by a host of cytochrome enzymes which convert it into several metabolites for further processing. In a recent study published in Neurology, researchers investigated if caffeine is metabolized differently in these patients and if caffeine metabolites can be used to efficiently diagnose the disease.
The researchers recruited 31 control healthy adults and 58 Parkinson’s patients. Each participant’s caffeine consumption was monitored over the study with one cup of coffee estimated to be 60mg of caffeine and 20mg for green tea. The patients’ blood was collected periodically after overnight fasting and was analyzed for caffeine and caffeine metabolites.
Interestingly, caffeine and nearly all of its 11 metabolites were significantly lower in patients with Parkinson’s than in healthy adults, suggesting that patients with Parkinson’s metabolize caffeine differently from healthy adults. When the researchers statistically analyzed caffeine as a biomarker, they found it was moderately successful in diagnosing Parkinson’s. However, when combined with the caffeine metabolites data, the researchers found that accuracy in the diagnosis was dramatically improved, suggesting a combined analysis approach provides the best outcome for reliable Parkinson’s diagnosis.
Is There a Genetic Component to the Metabolism of Caffeine in Parkinson’s Patients?
Though the exact cause of Parkinson’s disease is unknown, Parkinson’s can be passed down within families suggesting an underlying genetic predisposition. To determine if abnormal Parkinson’s caffeine metabolism is genetically linked, the researchers sequenced patient DNA. However, no significant genetic link was found to be associated with abnormal caffeine metabolism. This suggests that abnormal caffeine metabolism is a symptom of Parkinson’s disease and is not linked with any genetic predisposition to Parkinson’s.
Parkinson’s disease is a progressive neurodegenerative disease that typically affects adults over 65 years old. The researchers in this study found caffeine is metabolized differently in Parkinson’s patients which can be utilized to effectively diagnose Parkinson’s disease. Though Parkinson’s is known to have some genetic link, researchers found no evidence that abnormal caffeine metabolism is an underlying genetic cause for Parkinson’s. While this research needs to be repeated for early diagnosis of Parkinson’s disease, these results are promising to provide physicians a reliable and universal method to diagnose early Parkinson’s disease.
Written by Aaron Kwong, MSc
(1) Fujimaki, M. et al.Serum caffeine and metabolites are reliable biomarkers of early Parkinson disease. Neurology 0,1212/WNL.0000000000004888 (2018).
(2) Wong, S. L., Gilmour, H. & Ramage-morin, P. L. Parkinson’s disease: Prevalence , diagnosis and impact. (2014).