Parkinson’s disease cases expected to double worldwide by 2050

Parkinson’s disease cases are projected to double globally by 2050, reaching 25 million individuals, according to a recent modeling study published in BMJ. Population aging (increasing median age) emerged as the primary driver of this increase, followed by population growth (rising total number of people), with the largest increases expected in East Asia and among people aged 80 and older.

The study, led by Dongning Su, MD, expects the all-age prevalence to rise by 76%, while the age-standardized prevalence, which adjusts for demographic shifts, is projected to increase by 55%. Population aging will likely fuel 89% of the increase, followed by population growth (20%).

In an accompanying editorial, Tobias Kurth, professor, Charité – Universitätsmedizin Berlin, and Ralph Brinks, chair of Medical Biometry and Epidemiology, Witten/Herdecke University) argue that the study researchers’ projections may actually underestimate future Parkinson’s cases, due to the study reliance on prevalence extrapolation, which assumes current patterns will remain unchanged. 

The editorial also raises concerns about the use of population attributable fractions (PAFs) in estimating lifestyle-related risk factors. It warns that PAFs assume direct causality, which oversimplifies complex disease processes and may misrepresent the impact of risk factor modifications on future Parkinson’s prevalence.

The original study researchers explored how lifestyle factors might affect future Parkinson’s disease cases, suggesting physical activity could reduce numbers while smoking cessation might paradoxically lead to higher prevalence rates.

The editorial authors advocate for more advanced modeling techniques, particularly the illness-death model, which is described as providing “a more accurate representation of disease dynamics.” This approach accounts for transitions between health states – from healthy to diagnosis, from healthy to death and from diagnosis to death – creating more realistic projections for healthcare planning.

As Parkinson’s cases continue to rise, both the original study team led by Su and the editorial authors emphasize the need for rigorous modeling to guide resource allocation, inform policy decisions and advance research efforts.