No evidence for heritability of Parkinson disease in Swedish twins. I know when I speak in the community on neurodegenerative conditions like Parkinson’s and Alzheimer’s, there is usually surprise and quite a bit of resistance when I describe them as diseases of lifestyle. However, the research is pointing more and more towards (sound familiar??) oxidative stress and inflammation leading to mitochondrial dysfunction. Ultimately the cells cannot keep up with the damage being done to themselves and they commit suicide (a process called apoptosis). Lose too many cells this way and you start losing function. No evidence for heritability of Parkinson disease in Swedish twins — Wirdefeldt et al. 63 (2): 305 — Neurology –