In the original description of Parkinson’s disease, by none other than Dr. James Parkinson himself, he described a characteristic feature of the disease: constipation—torpid or lethargic bowels, which may precede the diagnosis by many years. In fact, bowel movement frequency may be predictive. Men with less than daily bowel movements were four times more likely to develop Parkinson’s an average of 12 years later. Now, this could just be a really early symptom of the disease, tied to decreased water intake. Many Parkinson’s patients report never really feeling very thirsty; maybe that led to the constipation. Or, alternately, the constipation may increase the risk of Parkinson’s disease, as constipation results in a longer stay of the waste in the bowel, and, thus, more absorption of potential neurotoxicants—neurotoxins from the diet.
Yes, there are two studies suggesting an association between constipation and Parkinson’s, but at the same time, there are 38 studies linking the disease to pesticide exposure. And, by now, more than a hundred studies linking pesticides to an increased risk of up to 80%.
Now, many of these studies are on occupational exposure—like farmworkers, who may reduce their risk of Parkinson’s by wearing gloves and washing their clothes. But Parkinson’s has also been linked to ambient exposure. Approximately a billion pounds of pesticides are applied annually in the U.S., and just living or working in high-spray areas may increase Parkinson’s risk. And the same with using pesticides in the home. I didn’t realize how common household pesticide use was, but this study out of UCLA suggests it might not be such a good idea.
Pesticides may cause DNA mutations that increase susceptibility for the disease, or play a more direct role. See, many neurodegenerative diseases appear to be caused by the buildup of misfolded proteins. In Alzheimer’s, it’s the protein amyloid beta; in Creutzfeldt–Jakob and Mad Cow disease, it’s prions; in Huntington’s, it’s a different protein; and in Parkinson’s disease, a protein called alpha synuclein, and a variety of pesticides—8 out of the 12 they tested—were able to trigger synuclein accumulation in human nerve cells, at least in a petri dish.
The buildup of synuclein may play a role in killing off specialized nerve cells in the brain—70% of which are gone by the time the first symptoms arise. Pesticides are so good at killing these neurons that pesticides are used to try to recreate Parkinson’s disease in lab animals. Is there any way to stop the process? Well, there’s no drugs yet that can prevent this protein aggregation.
What about flavonoid phytonutrients, natural compounds found in certain fruits and vegetables? They can cross the blood-brain barrier, and may have neuroprotective effects. So, they tested 48 different plant compounds to see if any could stop the clumping of synuclein proteins into the little fibers that clog up the cell. And they found a variety of flavonoids that can not only inhibit the spider web-like formation of synuclein fibers, but some could even break them up. Turns out flavonoids may actually bind to synuclein proteins and stabilize them.
Here’s some healthy brain cells; the arrows are pointing to the neurites, the arms that nerve cells use to communicate with each other. Here’s after exposure to a pesticide, though. The cell is damaged; retracts its little arms. But if you first incubate the nerve cells with a blueberry extract, the nerve cells appear better able to withstand the pesticide effects. So, this implies that flavonoids in our diet may be combating Parkinson’s disease as we speak, and healthy diets may be effective in preventing and even “curing” the disorder.
But these were all petri dish experiments in a laboratory. Is there any evidence that people eating blueberries are protected from Parkinson’s? There was this study, published forever ago, that suggested the consumption of blueberries and strawberries was protective. But this was a tiny study, and the results were not statistically significant—which is why I never brought up the study before. But that was the best we had, until now.
Those eating a variety of phytonutrients were less likely to develop Parkinson’s disease; specifically, higher intake of berries were associated with significantly lower risk. The accompanying editorial, “An Apple a Day to Prevent Parkinson Disease,” concluded that more research is necessary, but until then, an apple a day might be a good idea. Of course, this is coming from a man. Apples appeared to be protective against Parkinson’s for men, but not women. However, everyone appeared to benefit from the berries.
We just may not want to have our berries with cream, as the milk supply may be contaminated with the same kind of neurotoxic pesticide residues found in the brains of Parkinson’s disease victims.