Parkinsons and Pesticides

By Joel Fuhrman, M.D.

Numerous Studies Show Strong Links Associated With Exposure!

Although genetics are a factor in young-onset (before age fifty) Parkinson’s disease (PD), most PD is attributed to non-genetic factors. Age, head trauma, milk consumption, consumption of well water, and exposure to pesticides all have been implicated in connection with PD.3

Strong connections between pesticide exposure and PD have been established by a large number of epidemiological studies. A meta-analysis published in 2000 reviewed 19 individual studies,4 a review published in 2006 discussed 38 different studies, 3 and several more reviews have been published since then.

The scientists involved in these reviews have concluded that pesticide exposure is a major risk factor for PD. Furthermore, many of these scientists suggest that neurotoxic effects of pesticides are the mechanism by which farm chemicals and well water consumption contribute to PD.

Which pesticides are responsible? Herbicides and insecticides are the two classes of pesticides that have strong associations with PD. More specifically, individual studies have implicated the following pesticides:


Paraquat is an herbicide that may damage dopaminergic neurons via lipid peroxidation.5 Some facts associated with paraquat include:

  1.  used on a variety of crops including vegetables, soybeans, grains, cotton, grasses, sugar cane, peanuts, and potatoes;
  2.  used to control weeds around commercial buildings .6


Rotenone is an insecticide that may contribute to intracellular deposits characteristic of PD.7 Some facts associated with rotenone include:

  1. naturally occurring toxin present in some plants;
  2. used to kill insects, spiders, and fish;
  3. before 2005, was allowed to be used in organic farming;
  4. with a half-life of only 1-3 days, there is no concern of rotenone accumulating in the environment.8


This year alone, two studies reported links between organochlorine pesticides and PD.9,14 Scientists have concluded that there is a 120 percent increased risk of PD in those exposed to organochlorines. 9 Organochlorines are fat-soluble pesticides, and most people are exposed to them via fatty foods in their diets—mainly meat, dairy products, and fish.10

Organochlorines that are associated with PD include:


Dieldrin was used on cotton and corn from 1950- 70, and also for termite control until 1987.12 Most likely modes of exposure are contaminated dairy products and meat.13


Researchers found beta-HCH in the blood of 76 percent of PD patients, but only 40 percent of healthy controls.14


Permethrin may contribute to PD by altering dopamine uptake in the brain.15 It is used as an agricultural insecticide; as a topical treatment for head lice and scabies; and in household products, such as flea dips for pets, insect sprays, and mosquito- repellent clothing.16

Avoiding Exposure

How can you avoid or minimize exposure to these pesticides?

  1. Buy organic produce when possible. The USDA does not permit the use of synthetic pesticides on produce labeled organic.17
  2. Avoid household insecticide products.
  3. Do not drink well water.
  4. Minimize consumption of dairy, meat, and fish, as these are the most common modes of exposure to organochlorine pesticides.


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