See also:
"Parkinson's disease, insulin resistance and novel agents of neuroprotection."
Aviles-Olmos I, Limousin P, Lees A, Foltynie T.
Brain. 2013 Feb;136(Pt 2):374-84. doi: 10.1093/brain/aws009. Epub 2012 Feb 17.
http://www.ncbi.nlm.nih.gov/pubmed/22344583

"Multiple avenues of research including epidemiology, molecular genetics and cell biology have identified links between Parkinson's disease and type 2 diabetes mellitus. Several recent discoveries have highlighted common cellular pathways that potentially relate neurodegenerative processes with abnormal mitochondrial function and abnormal glucose metabolism. This includes converging evidence identifying that peroxisome proliferator activated receptor gamma coactivator 1-α, a key regulator of enzymes involved in mitochondrial respiration and insulin resistance, is potentially pivotal in the pathogenesis of neurodegeneration in Parkinson's disease. This evidence supports further study of these pathways, most importantly to identify neuroprotective agents for Parkinson's disease, and/or establish more effective prevention or treatment for type 2 diabetes mellitus. In parallel with these advances, there are already randomized trials evaluating several established treatments for insulin resistance (pioglitazone and exenatide) as possible disease modifying drugs in Parkinson's disease ..."

Perhaps we should spend more time discussing the relationship between PD progression and diet.

John