What does the gut have to do with the development of Parkinson’s disease?
Parkinson’s disease it is a steadily worsening neurodegenerative disorder that leads to death and affects about 1 in 50 people as they get older. A small minority of cases are genetic, running in families, but 85% to 90% of cases are sporadic, meaning they seem to appear out of nowhere. Parkinson’s disease is caused by the death of a certain type of nerve cell in the brain. Once about 70% of them are gone, symptoms begin. What kills these cells? Still is not completely clear, but abnormal accumulation of a protein called alpha-synuclein or α-synuclein is thought to be involved. Why? The researchers injected mixed Parkinson’s brain into the heads of rats and monkeys, and Parkinson’s pathology and symptoms were induced. It can happen even when you inject only the pure, aggregated α-synuclein strands. But how do these clumps actually end up in the brain?
As I discuss in my video The role that meat can play in causing Parkinson’s diseaseeverything seems to start in the gut. The part of the brain where pathology often first appears is directly connected to the gut and us have Direct evidence of the spread of Parkinson’s pathology from the gastrointestinal tract to the brain: α-synuclein from the brains of Parkinson’s patients is taken up in the gut wall and drags the vagus nerves from the gut to the brain—at least that’s what happened in rats. I wish we could go back and look at people’s colons before they got Parkinson’s. Indeed, we can. Old colon biopsies from people who later develop Parkinson’s disease was eliminated and, years before symptoms appeared, you could see α-synuclein in their gut.
Research is supported from the Michael J. Fox Foundation has discovered that you can reliably distinguish the colon of patients from controls by the presence of this Parkinson’s protein found in the gut wall. But how did it get there in the first place? Hectare “Vertebrate food products … a potential source of prion-like α-synuclein”? Indeed, almost all animals with backbones that we eat—cows, chickens, pigs, and fish—express the protein α-synuclein. So when we eat common meat products, when we eat skeletal muscle, we are eating nerves, blood cells, and the muscle cells themselves. Each pound of meat contains, on average, half a teaspoon of blood, and this alone could be a source of α-synuclein that could potentially trigger a cascade of accumulation of our own α-synuclein in the gut. Although “it may seem intuitive that dietary α-synuclein could cause seed accumulation in the gut,” this type of accumulation, what evidence do we have that it actually occurs?
We have some pretty interesting facts. There is a surgery called a vagotomyin which the large nerve that goes from our gut to our brain – the vagus nerve – is cut as an old remedy for stomach ulcers. Would Interrupting Gut-Brain Communication Reduce Parkinson’s Risk? Apparently so, suggesting that the gut to brain vagus nerve may be critically involved in the development of Parkinson’s disease.
Of course, “many people regularly consume meat and dairy products, but only a small fraction of the general population will develop PD, Parkinson’s disease. Therefore, there must be other factors that “may provide an opportunity for unwanted dietary α-synuclein to enter the host and initiate disease.” For example, our gut becomes more leaky as we age, so could that play a role? What else makes our gut leaky? “Dietary fiber deprivation has also been shown to degrade the intestinal barrier and enhance pathogen entry.” Well, this increases “Possibilities for food-based therapies.”
Parkinson’s patients have significantly less Prevotella in their intestines, a friendly herbivorous flora that strengthens the function of our intestinal barrier. So, low levels Prevotella are associated with a leaky gut, which has been linked to intestinal α-synuclein deposition, but high-fiber foods can cause Prevotella levels back. Therefore, it is possible that by adopting a plant-based diet, in addition to the beneficial effects of phytonutrients, increasing total fiber intake may modify gut microbiota and gut permeability [leakiness] in beneficial ways for people with PD.”
So, does does a vegan diet—high in fiber and no meat—reduce the risk of Parkinson’s disease? Parkinson’s disease “appears to be rare in quasi-vegan cultures,” with percentages hectare about five times lower in rural sub-Saharan Africa, for example. All this time we were thinking The benefits observed for Parkinson’s disease from plant-based diets were due to the antioxidant and anti-inflammatory nature of the animal-free diet, but may also be due to increased intestinal exposure to plant fiber and decreased intestinal exposure to nerve, muscle, and blood.
Wasn’t that exciting? For more on Parkinson’s see the related posts below.
