RFK’s Policies May Increase Risk of Parkinson’s and Other Chronic Diseases

The anti-vaccine policies of Secretary of Health and Human Services Robert Kennedy have rightfully caused great distress among many parents, public health professionals and primary care physicians, given the efficacy of vaccines in preventing measles, mumps, polio, influenza, and COVID-19, among many debilitating infectious diseases.

In contrast to these policies, Kennedy’s apparent aim of reducing exposure to toxic pesticides, herbicides and food additives has been treated, even by some public health advocates, as a positive turn toward regulation. Removing toxic dyes and food additives from the food supply appears to be a step in the right direction, as these chemicals include many carcinogens. However, Kennedy’s stated goal to protect the public from harmful chemicals is essentially significantly set back by his own support for massive cuts to federal institutions for public health research.

For many infectious and communicable diseases, the presence of an external biological agent — whether, bacterial, viral or fungal — is generally widely accepted within medical and public health communities. However, these agents are unlikely to be the main cause of neurodegenerative diseases such as Alzheimer’s and Parkinsons, many cancers, arthritis, heart disease, diabetes, and stroke. For many of these diseases — which make up the majority of the maladies affecting Americans — there are significant indications that environmental and occupational toxins are primary causes. This is certainly the case for Parkinson’s Disease, Type I diabetes, liver and bladder cancer, mesothelioma, and some heart disease. Prevention in these cases depends on unambiguously identifying the synthetic agents which cause these illness and then taking regulatory action to remove them from the environment.

However, the cutbacks in critical programs at the National Institutes of Health, particularly the National Institutes of Environmental Health Sciences, the Center for Disease Control, and the Environmental Protection Agency (EPA) sharply limit researchers’ ability to identify etiological agents of chronic disease. As a consequence it will be extremely difficult to produce the kind of research that enables us to determine which chemicals are public health hazards, and to regulate them.

For decades, manufacturers have suppressed or downplayed strong evidence for the toxicity of the environmental and occupational chemicals that they produce. The efforts of industry to oppose this research are well documented in the cases of lead and mercury poisoning, asbestos induction of mesothelioma, vinyl chloride induction of liver cancer, aromatic amines inducing bladder cancer. These efforts have a long history that has been documented time and time again.

In fact, the first head of the Environmental Section of the National Cancer Institute, Wilhelm Hueper, was driven from office by the Dupont Corporation due to his pursuit of the carcinogenicity of their aromatic amine compounds. Unfortunately, the critical data identifying environmental and occupational toxins still needs to be gathered for the majority of chronic disease afflicting our communities. Kennedy’s policies, from his cuts to crucial science funding to dismissal of leaders of the Centers for Disease Control (CDC) and Food and Drug Administration (FDA), will make it even harder to bring these agents to light.

To make the stakes clearer, let’s consider a major chronic disease, Parkinson’s, which afflicts more than one million Americans. Parkinson’s causes loss of control of skeletal muscles due to damage to proteins in a region of the brain called the substantia nigra. Over the past decades a great deal of biomedical research, publicly funded by the National Institutes of Health, has revealed key features of the pathology of the disease. This results from damage to critical brain proteins including alpha-synuclein, needed in the substantia nigra for the production of dopamine used by nerve cells controlling skeletal muscles.

Until the recent Trump administration cutbacks across science and public health agencies, dozens of laboratory teams were able to study the disease by inducing it in rats, mice, dogs and other experimental animals. Ingestion of a single dose of the organic biochemical MPTP has been found to induce Parkinson’s-like pathology in the animal models. MPTP is a byproduct associated with the synthesis of both legal medicines and psychotropic agents. The striking toxicity of MPTP in humans was discovered through its dramatic effects on a group of students in California, described in “The Case of the Frozen Addicts”.

The vast majority of Parkinson’s cases are unlikely to be due to ingestion of MPTP (though this may be present as a contaminant in some psychotropic medicines). However, its close cousin, the herbicide paraquat, is manufactured in the United States and sprayed on many food crops to the tune of thousands of tons — 8,000 tons in 2024 alone. Paraquat is used on numerous widely planted crops, including grains, vegetables, peanuts, and animal feed crops. It is also used on orchard crops, such as hops and grapes, and used in non-crop areas including fencerows and airport runways.

Paraquat is highly toxic to humans, as ingestion can be lethal if in sufficient amounts. More than 50 countries have banned its use as an herbicide in the environment. Paraquat is well-established as inducing Parkinsons-like disease in animal models. There is also considerable evidence linking paraquat exposures to increased incidence of Parkinson’s in humans: Thousands of legal actions have been brought against the manufacturer, but these are currently tied up in the courts. Nonetheless, within the U.S., it remains in widespread use. The chemical industry has worked actively to minimize the assessment of its toxic dangers, and official reports are ambiguous in terms of its dangers from entry into the food supply. Given these efforts, public health is absolutely dependent on the continuation of the independent publicly funded investigations carried on by the National Institutes of Environmental Health, other NIH programs, and the Centers for Disease Control.

The toxicity of paraquat to humans is well documented, as is its induction of Parkinson’s disease in animal models. Historically, the major path forward in such situations is continuing epidemiology studies which examine the incidence of the disease in humans as a function of exposure to paraquat. Government agencies such as the National Institute of Environmental Health Sciences or the Environmental Protection Agency are the only sources of funding for such studies that can be cited in efforts to regulate chemicals like pesticides, herbicides, and food additives. Unfortunately, the cutbacks noted above will almost certainly sharply reduce such research. As a consequence, Paraquat will potentially continue to be widely used in the U.S., a likely cause of some of the 90,000 new cases of Parkinson’s diagnosed each year.

But paraquat is already a well-known toxin. Innumerable other chemicals, some poorly understood or not yet identified, are continuing to enter our environment through industrial, agricultural and other routes. The inability to conduct intensive research into these chemicals puts communities across the country at greater risk of chronic, debilitating diseases which may otherwise be prevented.

Secretary Kennedy’s concern for food additives may be authentic, but he has not matched it with support for continued epidemiologic and public health research or more robust regulatory action by FDA or EPA. Without a major change in HHS, FDA and EPA policies, the outlook for progress in preventing Parkinson’s as well as other diseases due to toxic exposures is bleak.