What is Parkinson’s disease? What is alpha-synuclein?
Parkinson’s disease is a progressive neurological disease marked by loss of voluntary movement and a host of non-motor symptoms, such as gastrointestinal issues, cognitive decline and loss of sense of smell. These symptoms are the result of cell damage linked to the spread of a dysfunctional form of the protein alpha-synuclein, clumps of which are found throughout the brains of people with the disease.
Scientists do not yet know what role normal alpha-synuclein plays in the human body. Faulty forms of alpha-synuclein, however, have been clearly linked to Parkinson’s. These proteins move from cell to cell, prompting normal alpha-synuclein they encounter along the way to change shape and stick together to form clumps called Lewy bodies. These masses of damaged proteins clog up cells and prevent them from carrying out their normal functions, ultimately causing cell damage and death.
This is generally a slow process; people with Parkinson’s disease have reported experiencing non-motor, precursor symptoms of the disease years or even decades before their official diagnosis. The greatest risk factor for Parkinson’s disease is advanced age; most people are diagnosed after age 50.
Does meat cause Parkinson’s disease? Why look at meat consumption as a risk factor?
Thus far, research is lacking on whether consuming meat may contribute to Parkinson’s; this paper explores whether it is possible for external sources of alpha-synuclein to contain faulty alpha-synuclein and whether ingesting such external sources of alpha-synuclein has relevance to the disease.
Certainly, there is likely no singular cause for the majority of cases (with the only exception being a small number of cases that are the direct result of known genetic mutations passed down through families).
Parkinson’s is incredibly complex and likely is has an equally complicated set of factors that contribute to its onset and progression, including genetic and epigenetic risk, environmental influences, the level of inflammation and, most prominently, aging.
In their review, Drs. Killinger and Labrie analyzed published scientific literature to see if external sources of alpha-synuclein are capable of entering nerve cells in the gut and whether this could affect the risk of developing Parkinson’s.
Most vertebrates—including humans, cows, pigs and chickens—have alpha-synuclein in their tissues. Because humans consume meat products and because the gut has been implicated as a possible starting point for Parkinson’s, exploring whether or not there is a connection is a logical step.