Pesticide in Milk May Be a Risk Factor for Parkinson’s

Research published in Neurology analyzed the effects of heptachlor epoxide — a pesticide commonly used in milk until the 1980s — in association with the signs and symptoms of Parkinson’s.

Heptachlor was commonly used as a pesticide between 1960 and 1970, but its commercial sale wasn’t banned until 1988, according to the Environmental Protection Agency (EPA). The effects of heptachlor on humans are not well known; however, the EPA has found it causes convulsions, difficulties with pregnancy, and liver and kidney damage in rats.

The study, led by Dr. R. D. Abbott of Shiga University of Medical Science in Otsu, Japan, examined more than 449 male participants of Japanese-American heritage over a period of 30 years. The average age of participants was 54 at the beginning of the study. After the participants died, the researchers of the study performed autopsies of their brains in order to analyze the substantia nigra and levels of heptachlor epoxide.

The substantia nigra plays an important role in Parkinson’s research. According to the US National Library of Medicine, “Nerve cells in the substantia nigra send out fibers to tissue located in both sides of the brain. There the cells release essential neurotransmitters that help control movement and coordination.”

The study found heptachlor epoxide in 90 percent of participants who drank milk regularly, compared with 63 percent for participants who did not drink milk at all. The study also found that nonsmokers who drank two cups of milk per day had 40 percent fewer brain cells. 

However, Dr. Abbott noted in an American Academy of Neurology press release, “The researchers do not have evidence that the milk participants drank contained heptachlor epoxide.” He also stated, “The study does not show that the pesticide or milk intake cause Parkinson’s disease; it only shows an association.”

Parkinson’s disease is a severe neurological disorder in which cell death in the brain causes significant health issues, including reduced movement, muscle control and balance, according to the Parkinson’s Disease Foundation. Approximately one million Americans have Parkinson’s, with roughly 60,000 new cases diagnosed in the U.S. each year.


However, there are a few ways you can begin your pathway to possible Parkinson’s prevention:

  • Increase your folic acid (folate) intake by eating more raw, fresh vegetables. Folic acid deficiency may have an association with Parkinson’s, according to a study published in the Journal of Neurochemistry (2002).
  • Avoid any pesticides. Though heptachlor epoxide has been banned, steering clear of all pesticides is a safe bet.
  • Keep your iron and manganese levels balanced. Some research has associated excess iron and manganese levels with Parkinson’s. Talk to your doctor or nutritionist about how to achieve this balance.

Adding a few essential nutrients to your diet in the form of fresh fruits and vegetables, and avoiding items that may increase risk factors, are perfect places to start. Preventive knowledge is often the best way to reduce your risk for many of the chronic diseases out there.