News

Regional decline in the incidence rate of Parkinson’s disease – A trend worth exploring

  • Luxembourg Centre for Systems Biomedicine (LCSB)
    20 January 2025
  • Category
    Research
  • Topic
    Life Sciences & Medicine

A new cohort study analysing health insurance data from Germany reveals an intriguing trend: the rate of new cases of Parkinson’s disease (PD), also referred to as age-specific incidence, is declining. Researchers from the University of Luxembourg and the German Center for Neurodegenerative Diseases (DZNE) analysed data between 2006 and 2018 from nearly 450,000 individuals insured by Germany’s largest health provider AOK and showed that the risk of developing Parkinson’s dropped by about one fifth in individuals over 50, even after adjusting for known PD risk factors such as diabetes, hypertension, and traumatic brain injury. At the same time, the average age of diagnosis shifted upwards by nearly two years in men and slightly less than one year in women, indicating a potential shift toward later onset. The study has recently been published in Journal of Parkinson’s Disease.

Regional differences to be studied in a complex global context

“The declining incidence rates in Germany are encouraging, but must be viewed in the context of the increasing number of people already affected by Parkinson’s disease as people live longer. In addition, a large number of baby boomers is now entering the older age groups where the risk of Parkinson’s is high. Therefore, the absolute number of cases will continue to rise, even though age-specific rates have declined and may continue to decline,” explains Dr Anne Fink, researcher at the German Center for Neurodegenerative Diseases (DZNE) and first author of the study.

The recent German findings align with similar studies in Canada, South Korea, and the Netherlands, which also report declining or stable PD incidence rates. However, contrasting trends in countries like the United States, where PD incidence is increasing, suggest a role of regional societal or environmental factors, such as pesticide and industrial solvent exposure.

“There are most likely a multitude of factors at play”, says Prof. Jochen Schneider, principal investigator of the Medical Translational Research group at the University’s Luxembourg Centre for Systems Biomedicine (LCSB) and Department of Life Science and Medicine. “Previous research has shown that certain pesticides have neurotoxic effects. Paraquat, for example, has been linked to Parkinson’s disease and its use has been banned by the European Union (EU) in 2007.”

Other factors include improved air quality and decreased exposure to neurotoxic chemicals such as trichloroethylene (TCE). Commonly used as an industrial metal degreasing solvent, this compound has also been linked to the disease and was banned in the EU in 2016. Regions, such as the United States, where TCE and pesticides like paraquat remain prevalent have shown increasing PD incidence rates.

The road ahead: isolating biological and societal factors

While the exact reasons for declining PD incidence in Germany remain unclear, the findings highlight the complexity of disease dynamics. Factors like birth cohort size, improved healthcare access, and changing diagnostic patterns could contribute to the observed trends. “Our results underscore the need for further research to disentangle the biological and societal factors shaping these trends,” Dr Fink notes. Further understanding the underlying risk factors could pave the way for innovative public health strategies, fostering healthier aging worldwide.

“The observed decline in incidence rates offers hope, but as those diagnosed are living longer we need continued research and innovation in diagnostics, disease-modifying therapies, and patient support,” concludes Prof. Jochen Schneider.


Original publication: Fink A, Pavlou MAS, Roomp K, Schneider JG. Declining trends in the incidence of Parkinson’s disease: A cohort study in Germany. Journal of Parkinson’s Disease. December 2024. Doi:10.1177/1877718X241306132

Top picture based on an image designed by Freepik.

Meet the researcher

  • Assist. Prof Jochen SCHNEIDER

    Assist. Prof Jochen SCHNEIDER

    Assistant professor / Senior research scientist, Medical Translational Research group