A paradoxical plus for Parkinson's in UK's new 'generational smoking ban'.

The United Kingdom's recently enacted Tobacco and Vapes Bill introduces a "generational smoking ban," prohibiting tobacco sales to anyone born after 2008. While this landmark legislation is intended to reduce the country's burden of cancer, cardiovascular disease, and stroke, it also may have an unintentional impact on the incidence of Parkinson's disease (PD). Convergent data from observational and genetic studies indicate that non-smokers have approximately double the risk of developing PD compared to smokers. Together with preclinical data, these epidemiologic results support a potential neuroprotective effect of tobacco constituents. The new UK public health policy creates a valuable opportunity to assess prospectively whether reduction in smoking leads to a measurable increase in the age-adjusted incidence of PD, in addition to a much larger decrease in diseases known to be caused by smoking. This natural experiment may paradoxically help prevent PD, both in the long-term by enhancing our understanding of its causes, and in the short-term by motivating efforts to investigate candidate neuroprotective influences within smoked tobacco. Importantly, these benefits may be realized even if the results suggest a causal relationship between smoking and reduced PD risk. Ideally, the insights gained will accelerate development of targeted, non-toxic therapeutic interventions that slow PD without the adverse health consequences associated with tobacco use.