Environmental Toxin Exposure tied to a Higher Risk of Alzheimer’s Disease, Study Finds
Frequent exposure to an environmental toxin is not good for one's brain health, a new study is reporting.
According to the research team from the non-profit, EthnoMedicine and the University of Miami Brain Endowment Bank, people who are chronically exposed to BMAA, which is a neurotoxin that can be found in some dangerous algal blooms, have a higher risk of developing neurodegenerative illnesses such as Alzheimer's disease, dementia, ALS and Parkinson's disease.
For the study, the team carried out two experiments, spanning 140 days each, on vervet monkeys. In the first experiment, the monkeys were fed three different diets, which were fruits with BMAA, fruits without BMAA and equal parts fruits with BMAA and a dietary amino acid called L-serine.
The researchers found vervets that were in the placebo group with zero toxin exposure did not have signs of neuropathology. The vervets that solely ate the toxin-laced fruits had developed neurofibrillary tangles and amyloid deposits, which can be early signs of Alzheimer's. Monkeys in the last group had a lower density of tangles.
"Our findings show that chronic exposure to BMAA can trigger Alzheimer's-like brain tangles and amyloid deposits," said lead author of the study, Paul Alan Cox, Ph.D., who is an ethnobotanist at the Institute for EthnoMedicine, reported in the press release. "As far as we are aware, this is the first time researchers have been able to successfully produce brain tangles and amyloid deposits in an animal model through exposure to an environmental toxin."
In the second experiment, the researchers only changed up the dosages of the toxin and found that monkeys who ate BMAA still had tangles and amyloid deposits in their brain tissues after 140 days.
"This study takes a leap forward in showing causality -- that BMAA causes disease," said study co-author, Deborah Mash, Ph.D., director of the University of Miami Brain Endowment Bank. "The tangles and amyloid deposits produced were nearly identical to those found in the brain tissue of the Pacific Islanders who died from the Alzheimer's-like disease."
The researchers conducted this study after they noticed that people from the village of Chamorro at the Pacific Island of Guam tended to develop a brain condition that was very similar to Parkinson's, ALS and Alzheimer's.
"Our field work was sort of like reading an Agatha Christie novel. Who is the murderer?" Cox explained to CBS News. "We knew that other peoples on Guam, including the Filipinos, the Caroline islanders, U.S. military personnel, and expatriate Japanese did not get the disease, only the Chamorro villagers. So as ethnobotanists, we spent our time in the villages, rather than in the clinic, trying to figure out who the hidden killer is."
Once the team turned to environmental factors that only pertained to the villagers, they found that many of the people there ate a diet that had BMAA. The researchers noted that they still did not find a cause-and-effect relationship.
The study's findings were published in the journal, Proceedings of the Royal Society B.