A new study has found a link between contaminants found in milk and the risk of developing the brain disorder Parkinson’s Disease.
While previous studies have found a correlation between dairy products and a higher risk of developing Parkinson’s Disease, there was little evidence to detail how dairy products like milk and cheese might be affecting people’s risk of the disease.
Now scientists reporting in the Neurology journal, have detailed the conclusions of a study of an environmental disaster in Hawaii in the 1980s to investigate the connection. At the time, an Organochlorine pesticide used by pineapple farmers made its way into the milk supply, when cow’s food was made in part from the pineapple debris.
Coincidentally, there was also a study of heart disease among Japanese-American men that involved more than 8,000 men who were followed from mid-life to death. The men provided detailed information including how much milk they drank and what they ate and some agreed to donate their brains for research upon death.
The study found that men who reported drinking more than two glasses of milk a day showed the thinnest nerve networks in that part of the brain most affected by Parkinson Disease, compared to men who drank little or no milk. The milk drinkers also had residues of specific organochlorines, called heptachlor epoxide.
Interestingly, by measuring when cells in these motor nerve regions died, they also learned that the accumulation of heptachlor epoxide occurred before the cells were damaged, strongly hinting that the chemical was responsible for triggering the changes associated with Parkinson’s.
The study did not have samples of the milk the men drank, so cannot be certain that the contaminated milk was the source of the pesticides they found in men’s brains, but it’s a reasonable explanation. The data doesn’t mean that anyone who drinks several cups of milk a day is putting them at risk of developing Parkinson’s.
What it does mean is that diet and lifestyle risk factors should be considered more deeply. The study’s author says he hopes his findings fuel the continued careful look at how chemicals in the environment might be affecting our health, even if indirect and not always obvious ways.