As a newbie, I've been bringing myself up to date on Parkinson's research. There seem to be almost as many theories for the mechanism by which the disease develops as there are scientists working on it!
One paper which caught my eye reported in 2007 that drinkers of black tea (in Singapore) had about a quarter of the risk of non-drinkers of developing PD.
(http://aje.oxfordjournals.org/content/167/5/553.full#sec-6). This has probably been discussed in an earlier thread.
When I looked in Google Scholar for papers which followed this up I found there is some rationale being established experimentally to explain the protective effect of black tea. Apparently black tea contains theaflavins which are potent anti-oxidants. An Indian group has shown that theaflavins protect nigral dopaminergic neurons (in a test tube) against a neurotoxin known to induce Parkinson's like symptoms, a Japanese group that theaflavins stimulate autophagy (putting in the cell dustbin) of alpha-synuclein(a protein most suspected of being the initiator of cell death in PD) and a German/American group have shown (in the test tube again) that theaflavins stop alpha-synuclein from turning rogue.
What I am wondering out loud is, if these experiments really do demonstrate the molecular basis for the protective effect of black tea then surely the same effects should slow down progression of the disease too?
I'll make a cuppa and think about it...........