Parkinson Pete Reviews "Ending Parkinson's Disease: A Prescription for Action"

Ray Dorsey, MD, Todd Sherer, PhD, Michael S. Okun, MD, Bastiaan R. Bloem, MD, PhD. Ending Parkinson’s Disease: A Prescription for Action. New York: Public Affairs, 2020. xiii + 315 pp.

I WAS PLEASED TO SEE the optimistic title of a new book that was published in 2020: Ending Parkinson’s Disease: A Prescription for Action. It had a promising dedication: “To those who bear the burden of Parkinson’s disease and to those who will help end it.” It has a distinguished quartet of authors who are medical men and experienced neuroscientists and neurologists. I read Ending Parkinson’s Disease with eager anticipation. Were these four medical men really going to tell the world how to end Parkinson’s disease? Did they really have a prescription for curing it? I hoped the answers to these questions were Yes and Yes, because then I could take the cure, forget about living and dying with Parkinson’s disease, and get on with my suddenly Parkinson’s-free life.

Unfortunately, the answers to the two questions were not Yes and Yes, but No and No. No, Parkinson’s will not end, at least not any time soon, and No, Drs. Dorsey, et al., do not have a cure for Parkinson’s.

The misleading title Ending Parkinson’s Disease does not mean that the authors have found the elusive cure that the millions of men and women worldwide who have Parkinson’s have been told for years was “just around the corner.” No, that is emphatically not what Drs. Dorsey, et al., mean. Rather, by “ending” Parkinson’s disease they mean that there may now be promising ways to prevent Parkinson’s from infecting people who have not yet been diagnosed. The authors make no effort to conceal where their “true passion” lies: “While we are hopeful about making our patients’ lives better, our true passion is preventing people from ever having to face Parkinson’s” (p. 7). In other words, their primary goal is not finding more effective treatments, let alone a cure, for those of us who have the disease, but preventing others from getting it.

The Causes of Parkinson’s

Drs. Dorsey, et al., propose to “end” this disease by finding out what researchers down through the years have discovered about what can cause Parkinson’s and then, where possible, eliminate those causes. It used to be common to use the term “idiopathic” to describe Parkinson’s, meaning that it was not known what caused it. Recent research has shown beyond reasonable doubt that while Parkinson’s is a disease of the brain, it is not caused by the brain. Most of us who have the disease were not born with defective brains.

Rather, our brains were damaged later when we unknowingly touched, ate, drank, or inhaled something that was bad for us and that gradually prevented our brain from producing the dopamine we need to be able to control our movements. The authors of Ending Parkinson’s Disease lay out convincing arguments that we now know what can cause some people to get the dreaded disease. Though it appears that Parkinson’s does, indeed, run in some families and is rarely found in some other families, the authors argue that at most only ten percent of people with Parkinson’s have a genetic predisposition that contributed to their getting the disease. Most cases of Parkinson’s are caused by manmade chemicals:

—pesticides. Farmers and farm workers who routinely handle pesticides, including ones containing paraquat and rotenone, are known to be at increased risk for Parkinson’s.

—insecticides. Chemicals like chlorpyrifos, widely used to discourage insects from damaging orange, apple, and almond crops, have been linked to Parkinson’s.

—defoliants. Many military personnel who served in Vietnam, where they were exposed to a herbicide called Agent Orange, later developed Parkinson’s.

—solvents. People who repeatedly use trichloroethylene to clean greasy auto parts, to clean electronic chips, and to dry-clean clothes are susceptible to getting Parkinson’s.

—polluted drinking water. An estimated thirty percent of the groundwater in the United States is contaminated by trichloroethylene, pesticides, and other Parkinson’s-inducing chemicals.

—polluted air. People who live near Superfund sites can get Parkinson’s from breathing contaminated air.

Except for the relatively few instances of the disease caused by genetics or by the head-trauma that often comes with service in the military or from participation in professional sports like boxing and football, the majority of people who get Parkinson’s get it from manmade chemicals used in agriculture and industry.

There were virtually no instances of the disease until the beginning of the nineteenth century, by which time the industrial revolution had already badly polluted the once-clean rivers, streams, and canals of London and darkened its once-clear skies with the smoky and murky by-products of the mills north of London. It was then that an observant north-of-London medical doctor, James Parkinson, happened to notice that six unrelated men walked, stumbled, and shook in similar ways. He interviewed the men, took notes, and then published in 1817 the essay that, many years after his death, would make his name famous.

Dr. Parkinson had no reason to suspect that “his” new disease was caused by the toxic industrial pollutants that had slowly attacked the substantia nigra portion of the brains of his six subjects and gradually prevented it from producing the dopamine that had once permitted the six shaking and stumbling men to control their movements. It took later generations of neurologists to observe the behavior and the reactions to various chemicals of certain laboratory animals and to analyze the histories and the reactions to various stimuli of many human patients, both male and female. And it fell to later generations of neurologists to devise the experiments that would verify their growing suspicions that Parkinson’s started not in the brain itself but in the lungs and the intestinal tracts, and their growing conviction that the primary causes of most cases of Parkinson’s were toxic chemicals with polysyllabic names.

Having determined the toxic chemical causes of Parkinson’s, it should be easy to protect men and women from those toxic chemicals and send Parkinson’s the way of bubonic plague, smallpox, polio, ebola, and other nasty diseases that no longer much trouble us. Our four authors put it this way: “The solution is to stop using such chemicals. Other countries with lower incomes and less strict environmental policies have banned paraquat. The United States should do the same. [...] We can no longer claim ignorance. If we continue to allow the use of these pesticides, we are choosing to permit the spread of Parkinson’s through the farms that we tend, the air that we breathe, and the water that we drink” (pp. 80–81).

Toxicity Fights Back

Banning the use of these substances, however, has proved to be difficult. The officers of the Environmental Protection Agency are under pressure to ban the use of potentially harmful chemicals that are strongly suspected of causing Parkinson’s. They are also under pressure from lawyers retained by chemical companies and agricultural interest groups. Farmers have come to count on reasonably-priced pesticides and insecticides to keep the corn growing, the cows lowing, the milk flowing, the hay mowing, and the insects going on to the next farm.

Let us suppose that the EPA announces that it is considering banning the manufacture, distribution, and use of a manmade chemical pesticide known as “Kiloweed”—a made-up name for a made-up liquid weedkiller that its manufacturer advertises as “a safe, inexpensive, and easy-to-apply product that, used as directed, will keep your lawn, your garden, and your fields free of ugly weeds.” The EPA scientists have determined that Kiloweed is not really safe because homeowners and farmers who have used the product for ten or more years are getting Parkinson’s disease at an alarmingly high rate. In addition, tests of the groundwater in wells near farms that use Kiloweed show traces of the toxic chemical. Furthermore, laboratory tests show that when mice are fed wheat laced with Kiloweed, they tend to show signs of parkinsonism: tremors, slowness, and unsteady gait.

It is not difficult to imagine the nature of the counter-arguments that the Kiloweed lawyers will submit:

"Perhaps some farmers who have sprayed their crops with Kiloweed for a decade do develop signs of parkinsonism, but many do not. How can you be sure that in the ones who do, it was not caused by some other chemical in the fertilizer they used at some time in the past?"

"What can laboratory animals that are tortured by technicians in white coats teach intelligent humans about how we will react to certain chemicals?"

"Is Kiloweed safe? Sure it is. We print on every unbreakable plastic bottle of Kiloweed careful directions about how to store Kiloweed out of the reach of children on dry shelves in ventilated out-buildings. We print detailed safety instructions about wearing gloves and how to dispose of the empty containers. How can we be sure that everyone—indeed, that anyone—in your reference population wore gloves when they used our product?"

"It is not fair to proclaim Kiloweed to be unsafe because a few of our satisfied customers may use it in unsafe ways. Our customers are satisfied. They tell us often that they love Kiloweed because it cheaply and effectively controls the invasive weeds that would otherwise rob their cash crops of both sunshine and moisture. Their ordering more Kiloweed every spring is proof of their satisfaction."

"Farming, of course, is a risky business. Bad weather can ruin a season. Good weather can contribute to a bumper crop, but that can mean that all the farmers around also have bumper crops, thus driving prices so low that no one makes a profit. Barns can burn down. Tractors can break down. Farm hands can quit just when the crop needs to be harvested. Now you EPA folks want to ban the one sure thing in a farmer’s life, his ability to grow weed-free crops. And why? Because banning it may possibly keep someone, somewhere, sometime in the distant future from getting an exotic disease."

"You mentioned groundwater. You have presented no solid proof that the chemicals in Kiloweed have for sure caused people to develop Parkinson’s. Millions of people drank well-water for years and years, and they remain healthy and strong, with no signs of ill health. Now you want to destroy a robust and vital agrarian economy by banning those chemicals."

"If farmers go belly-up by your banning Kiloweed, what happens to the grocery stores that sell the nourishing produce grown on the farms you have are trying to put out of business? What about the many fine restaurants that serve up healthy vegetables grown on those farms you are trying to shut down? What happens to the city-dwelling families who eat cornflakes and broccoli? Why punish the lowly farmers by banning chemicals that help them provide life-sustaining nourishment to all of us?"

Is it any wonder that the EPA has backed down in the face of such arguments? Although a chemical called paraquat is known to increase the risk of getting Parkinson’s by 150 percent, and although many countries, including even China, have banned it, the American EPA has not done so. Indeed, the use of paraquat on agricultural fields in the United States has doubled in the last ten years.

In 2017 the EPA considered banning the solvent trichloroethylene, but after intensive lobbying by the chemical industry, the EPA decided to “postpone the ban indefinitely” (p. 5).

It does not appear that Drs. Dorsey, et al., are optimistic that their “prescription for action” will bring about the desired goal of “ending” Parkinson’s disease. They hold out little hope that the EPA will get any tougher on banning the harmful chemicals that invite Parkinson’s or, even if they did announce such bans, on enforcing them.

There is little reason to hope that the situation will get better any time soon. Indeed, a more accurate title for Ending Parkinson’s Disease: A Prescription for Action might be Unending Parkinson’s Disease: A Prediction of Inaction. Far from predicting that Parkinson’s will end because the harmful chemicals that cause it have been identified by the EPA, Drs. Dorsey, et al., predict that Parkinson’s will be with us for a long time, and in ever-increasing numbers. On the first page of their introduction they state: “Neurological disorders are the world’s leading cause of disability. And the fastest growing of these conditions is not Alzheimer’s but Parkinson’s disease. From 1990 to 2015, the number of people with Parkinson’s more than doubled from 2.6 million to 6.3 million. By 2040, the number will double again to at least 12.9 million, a stunning rise” (p. 1).

Ending Parkinson’s Disease is not all doom and gloom. Chapter 10, for example, suggests twenty-five “concrete steps that we can and should take to reduce the worldwide toll of this daunting disease” (p. 129). Note that the authors speak here merely of “reducing” the spread of the disease, not, as in the title, of “ending” the disease. Among these concrete steps are to ban paraquat and trichloroethylene, to clean up Superfund sites, to filter our drinking water, to eat a Mediterranean diet, to engage in regular and vigorous exercise but to avoid head trauma, to volunteer for clinical trials, to support greater funding for Parkinson’s research, to help find ways to make it possible for Parkinson’s patients to stay in their own homes, and so on.

Knowing what needs to be done and getting it done are often far apart. Meanwhile, Parkinson’s-causing pesticides and solvents are still with us, and Parkinson’s disease is still with us. Those who do not have Parkinson’s can hope that they do not get it and that Drs. Dorsey, et al., are taken seriously by politicians and by the scientists at the Environmental Protection Agency. Those of us who have Parkinson’s will have to continue to make the most of the years between the two d-words—that is, between diagnosis and death. We will have to learn to be grateful that medical researchers have improved our lives with discoveries like carbidopa/levodopa and deep brain stimulation. And, in the end, we will have to decide how we want to approach the second of those d-words, the one that no one much wants to talk about—including Drs. Dorsey, et al.