Parkinson's & Lewy Body
Starts in the gut, not the brain
Parkinson's disease — and its cognitive cousin Lewy body dementia — centre on misfolded alpha-synuclein that forms Lewy bodies in neurons. Growing evidence shows the disease often STARTS in the gut and the olfactory bulb, travelling up the vagus nerve years before motor symptoms appear.
Early red flags, 10+ years pre-diagnosis
Loss of smell (hyposmia/anosmia), REM sleep behaviour disorder (acting out dreams), chronic constipation, and persistent depression frequently precede motor symptoms by a decade or more. These are not universal, but when multiple are present, screening is warranted.
Exercise has the strongest prevention signal
In the Physicians' Health Study + Nurses' Health Study (together >200,000 participants), people in the top quintile of physical activity had ~40% lower Parkinson's risk vs the lowest. No drug has matched this. Vigorous aerobic exercise appears neuroprotective specifically for dopamine neurons.
Which cluster is most suggestive of prodromal Parkinson's?
Select every early signal worth flagging to a neurologist.
Exercise is the only disease-modifying intervention
There are no drugs that slow Parkinson's progression — only ones that manage symptoms. But high-intensity aerobic exercise (e.g., treadmill at 80-85% max HR, 3×/wk for 6 months) has shown trial-confirmed slowing of motor decline (SPARX trial, 2018). Mechanism: BDNF + neurogenesis + dopaminergic preservation. The dose matters: moderate exercise alone wasn't sufficient. If you have Parkinson's or are at high risk (RBD, anosmia, family history), aggressive cardiovascular training is your strongest single lever.
Key Takeaway
Parkinson's isn't just a tremor disease. The cognitive + prodromal features matter most for prevention. Anosmia, RBD, constipation, depression years before motor onset give you a window to intervene — primarily with aggressive exercise and gut-brain health.