Parkinson's disease is the second most common neurodegenerative disease in Japan, in which symptoms such as trembling and stiffness of limbs gradually progress.Recent studies have revealed that the decrease in the number of substantia nigra neurons in the midbrain, which is a characteristic of Parkinson's disease, progresses at least 2 years before the onset of the above symptoms, and the signs are found and treated as soon as possible. The importance of intervening "preemptive medicine" has been suggested.

　On the other hand, from around 2002, it has been found that ingestion of an appropriate amount of caffeine (about 1 to 1 cups of coffee a day) is effective in preventing the onset of Parkinson's disease.Therefore, the research group worked to elucidate the effect of caffeine on Parkinson's disease.

　First, we found that in patients with Parkinson's disease, blood caffeine levels were low.Therefore, the relationship between the stage and severity was expanded and evaluated for caffeine and all its metabolites, and the involvement of the metabolizing enzyme gene was also investigated.As a result, it was found that in Parkinson's disease patients, the blood levels of caffeine and its metabolites were decreased regardless of the severity, even if there was no difference in the metabolizing enzyme gene from the healthy subjects.From this, it was inferred that in Parkinson's disease patients, the absorption of caffeine was reduced, and it was difficult to obtain the protective effect.

　This result shows that caffeine and its metabolites are useful as biomarkers for diagnosing Parkinson's disease, leading to the development of a simple and minimally invasive diagnostic method for Parkinson's disease.Furthermore, it is expected that caffeine administration will lead to the possibility of prevention and treatment of Parkinson's disease.

Paper information:[Neurology] Serum caffeine and metabolites are reliable biomarkers of early Parkinson disease