(NaturalNews) An insect form of Alzheimer’s disease caused by aluminum contamination may be one of the causes behind an ongoing decline in populations of bees and other pollinators, according to a study conducted by researchers from the universities of Keele and Sussex and published in the journal PLOS ONE.
The researchers found that honeybees had levels of aluminum in their bodies equivalent to those that could cause brain damage in humans.
“Aluminium is a known neurotoxin affecting behaviour in animal models of aluminium intoxication,” said researcher Chris Exley, an expert on human aluminum exposure, as reported by the UK’s Daily Mail. “Bees, of course, rely heavily on cognitive function in their everyday behaviour and these data raise the intriguing spectre that aluminium-induced cognitive dysfunction may play a role in their population decline – are we looking at bees with Alzheimer’s disease?”
“Pathological” aluminum levels
Researchers from the University of Sussex first collected pupae from colonies of wild-foraging bumblebees, then sent these off to Keele University for analysis of their aluminum content.
Pupae are sacks that bumblebee larvae develop in before emerging into their adult forms. The pupae in the study were found to contain between 13 and 200 parts per million (ppm) of aluminum.
Just 3 ppm is “considered as potentially pathological in human brain tissue,” the researchers said.
Prior studies had shown that bees do not actively avoid aluminum-contaminated nectar while foraging, but the new study was among the first to show the consequences of this behavior.
Bees use sophisticated cognitive processes to forage for food over wide territories, and to communicate with other bees. Because aluminum has been shown to have negative effects of animal cognition, the new study raises the possibility that aluminum poisoning might be contributing to crashing populations of bees worldwide.
Dementia caused by aluminum poisoning is still likely to be just one of many factors currently devastating pollinator populations, however.
‘It is widely accepted that a number of interacting factors are likely to be involved in the decline of bees and other pollinators – lack of flowers, attacks by parasites, and exposure to pesticide cocktails, for example,” Exley said.
Much attention has focused on the family of pesticides known as neonicotinoids – systemic pesticides that infiltrate every portion of a plant, including the pollen and nectar. Three neonicotinoids have already been banned in Europe due to evidence of harm to pollinators.
Alarmingly, two recent studies published in the journal Nature suggest that bees may actually be particularly attracted to plants treated with neonicotinoids, preferentially visiting them over untreated plants. That’s because the pesticides contain a chemical similar to nicotine, which the bees may be getting addicted to much as humans get addicted to the nicotine in cigarettes.
“There’s a conundrum that they are attracted to the stuff that actually is having a negative impact on their motor function and their ability to collect food and forage,” said researcher Geraldine Wright of Newcastle University. Wright and colleagues offered honeybees and bumblebees a choice between sugar water solutions either containing or not containing low doses of neonicotinoids. The bees drank more from the pesticide-laced food sources.
The second study, conducted by researchers from Queen Mary University of London and Royal Holloway, University of London, found that bees infected with parasites were even more likely to drink from neonicotinoid-contaminated nectar than healthy bees. And while the pesticide did appear to slow the progress of the infections, it did not increase the bees’ life expectancy.
In fact, both healthy and unhealthy bees who consumed neonicotinoid-laced nectar showed negative side effects, including suppressed appetite. Healthy bees who drank more of the nectar had shorter lifespans than those who drank less.