A pesticide that is used in pineapple production and also found in milk has been linked to an increased risk of Parkinson’s disease in men.
Study author, R. D. Abbott, Ph.D. says that although there have been other studies that have examined the link between Parkinson’s disease and dairy products, “Our study looked specifically at milk and the signs of Parkinson’s in the brain.”
The study involved 449 Japanese-American men who were followed and examined for over 30 years until death. Autopsies were performed after death.
The researchers closely looked for lost brain cells in the substantia nigra region of the brain, which is a common sign of Parkinson’s disease that can occur years before first symptoms of the disease present themselves. Additionally, 116 brains were measured for residue of heptachlor epoxide residue, which is a pesticide found in milk products. The pesticide was originally used on pineapple plantations in Hawaii to kill insects until it was banned in 1980. Traces of the pesticide are also found in well water.
The study found that nonsmokers who consumed on average more than two cups of milk per day had 40 percent fewer brain cells in the substantia nigra when compared to those who drank less.
Smokers who drank milk showed no association between milk consumption and loss of brain cells and milk consumption. Previous studies have found that smokers show a reduced risk of developing Parkinson’s disease.
Abbott says pesticide residue was found in 90 percent of milk drinkers, compared to a reduced 63 percent for those of who did not drink milk.
Although the researchers note the findings reveal a link association between increased risk of Parkinson’s disease and milk, they have not been able to find the cause and effect of the correlation.
The researchers write in the study’s conclusion, “There are several possible explanations for the association, including chance. Also, milk consumption was measured only once at the start of the study, and we have to assume that this measurement represented participants’ dietary habits over time.”