Aluminum is a neurotoxin, that is, a poison to the brain and nervous system. Some experts have long speculated that this metal plays a role in Alzheimer’s disease, and evidence is steadily mounting that it indeed does. Fortunately, there’s also evidence that suggests that a number of natural plant extracts and nutrients can prevent and/or reduce aluminum toxicity in the brain and prevent the progression of memory loss and other cognitive deficits.
The evidence linking aluminum and Alzheimer’s disease
A team of neuroscientists led by Dr. Walter Lukiw, PhD, Professor of Neurology, Neuroscience and Ophthalmology at Louisiana State University, has been studying the potential contribution of aluminum to the onset, development and progression of Alzheimer’s disease for about 30 years. Dr. Lukiw and his fellow researchers recently summarized the research linking aluminum and Alzheimer’s disease in a peer-reviewed article published in Frontiers in Aging Neuroscience.
“Aluminum’s contribution to Alzheimer’s disease is based upon at least seven independently derived observations,” the researchers stated. Briefly, those seven pieces of evidence are:
- Aluminum strongly promotes beta-amyloid plaques in the brain at levels corresponding to those currently found in humans.
- Aluminum promotes inflammation in the brain by increasing the pro-inﬂammatory molecule known as nuclear factor kappa beta (NF-kB), a prominent feature in the brains of people with Alzheimer’s disease.
- Out of the many thousands of brain gene messenger RNA molecules (molecules that convey genetic information from DNA to cause gene expression), aluminum increases the same ones that are increased in Alzheimer’s disease.
- Adding aluminum to the diets of animals with Alzheimer’s disease causes additional brain changes associated with Alzheimer’s disease such oxidative stress, programmed cell death, and deficits in gene expression.
- Aluminum also causes the same types of cellular energy deficits that are associated with Alzheimer’s disease, such as impaired signaling involving ATP and energy utilization.
- A very signiﬁcant number of studies link the amount of aluminum in drinking water to the incidence of Alzheimer’s disease. (Worldwide, aluminum is added to drinking water as a clarification or “finishing” agent.)
- Out of all the Alzheimer’s disease drug treatments tried to date, chelation using an aluminum chelator has been shown to be one of the most effective therapeutic strategies yet.
Digging deeper: what animal studies have found
There is no ethically acceptable way to directly test whether aluminum causes Alzheimer’s disease in humans. Because it’s not ethical to dose humans with aluminum, researchers must rely on other scientific methods of investigation to determine aluminum’s role in this devastating disease. One way to do this is through animal studies.
It is now well-established that aluminum directly causes Alzheimer’s-like memory impairment, behavioral problems, and learning deficits in animals, even in very low doses.[2-5] For instance, rats that consume aluminum in amounts equivalent to those ingested by Americans from their food and water develop severe Alzheimer’s-type cognitive deterioration in old age.
Animals exposed to aluminum don’t just develop Alzheimer’s-like symptoms, they also show definitive evidence of Alzheimer’s disease in their brains.
- Aluminum accumulates in the brain cells of particular regions of the brain most prone to damage in Alzheimer’s disease.
- Many studies have demonstrated how aluminum causes beta-amyloid plaques to abnormally form in the brains of animals.[2,7-10] These plaques, the hallmark features of Alzheimer’s disease, form when pieces of sticky proteins called beta-amyloid clump together and block cell-to-cell signaling at synapses. They also activate immune system cells that trigger inflammation and devour disabled cells. Aluminum-induced beta-amyloid plaques occur in exactly the same brain regions in animals as they do in humans.
- Third, another brain change consistent with Alzheimer’s disease also occurs in animals exposed to aluminum: the formation of what are known as neurofibrillary tangles.[6, 10-12] Neurofibrillary tangles are abnormal collections of twisted protein threads found inside nerve cells that consist primarily of a protein called tau. Like beta-amyloid plaques, neurofibrillary tangles damage the ability of neurons to communicate with each other and are a hallmark feature of Alzheimer’s disease.
Prominent Researchers speak out
Different teams of researchers from all over the world have recently published papers outlining the convincing evidence from both human and animal studies and warning of the dangers of aluminum as a cause of Alzheimer’s disease.[10, 12-15]
It is enlightening to learn what some of these experts have to say about aluminum and Alzheimer’s disease in their own words.
- “Overall, the evidence indicates that Alzheimer’s disease is a human form of chronic aluminum neurotoxicity.” J.R. Walton, Faculty of Medicine, University of New South Wales, St George Hospital, Sydney, Australia
- “…studies suggest that aluminum may not be as innocuous as was previously thought and that aluminum may actively promote the onset and progression of Alzheimer’s disease.” Stephen Bondy, Environmental Toxicology Program, Center for Occupational and Environmental Health, Department of Medicine, University of California, Irvine, CA
- “The hypothesis that aluminum significantly contributes to Alzheimer’s disease is built upon very solid experimental evidence and should not be dismissed. Immediate steps should be taken to lessen human exposure to aluminum…” Lucija Tomljenovic, PhD., University of British Columbia, Vancouver, BC, Canada
- “There is growing evidence for a link between aluminum and Alzheimer’s disease… it is widely accepted that aluminum is a recognized neurotoxin, and that it could cause cognitive deﬁciency and dementia…” Masahiro Kawahara, Department of Analytical Chemistry, School of Pharmaceutical Sciences, Kyushu University of Health and Welfare, Japan
- “As scientific publications continue to support the hypothesis that aluminum toxicity is involved in Alzheimer’s disease, it would be prudent to adopt strategies for preventing excessive aluminum exposures…” Maire Percy, PhD, University of Toronto, Canada.
The case of the Alzheimer’s patient and the aluminum in his brain
Another of the world’s preeminent researchers studying aluminum’s negative health effects is Dr. Christopher Exley, PhD, of Keele University in the United Kingdom. Dr. Exley and his team have found that aluminum appears to accumulate in the brain with age. Their most recent research demonstrates that many people over the age of 70 have a potentially pathological amount of aluminum accumulated in their brains.
Dr. Exley and his colleagues were recently the first to demonstrate significantly elevated brain aluminum levels in an individual diagnosed with early-onset Alzheimer’s disease following occupational exposure to aluminum. Occupational exposure to aluminum is directly associated with impaired cognitive function; the more aluminum to which people are exposed, the poorer they perform on tests for memory and other cognitive functions.
The case presented by Dr. Exley involved a previously healthy man who was diagnosed with Alzheimer’s disease at age 58, after more than eight years of regular exposure to aluminum sulfate dust. At first, the man complained of headaches, tiredness, and mouth ulcers. He then started to show memory problems and began suffering from depression before he was finally diagnosed with Alzheimer’s disease.
After his death in 2011, his brain’s cerebral cortex was found to have abundant beta-amyloid plaques and neurofibrillary tangles, consistent with advanced Alzheimer’s disease. At the request of his family and the local coroner, samples of the man’s brain tissue were sent to Dr. Exley for analysis of aluminum. According to Dr. Exley, it is extremely rare to be given as much brain tissue as was provided for analysis, and the opportunity enabled the most thorough analysis of a brain region’s aluminum content ever undertaken.
The data confirmed the accumulation of aluminum in the man’s brain tissue. In some samples from the frontal lobe, the aluminum levels were excessive and high enough to cause disease. While Dr. Exley’s data cannot prove that aluminum caused the man’s aggressive Alzheimer’s disease, he states that it is highly likely given the known neurotoxicity of aluminum.
How to reduce your risk of aluminum-induced Alzheimer’s disease
With the growing evidence linking aluminum and Alzheimer’s disease, we all need to personally take steps now to reduce our exposure to this ubiquitous metal. Part 1 of this series, Does Antiperspirant Cause Cancer? Here’s Why You Should Be Concerned About Aluminum Toxicity, provided information on common sources of aluminum exposure, along with ideas on how to avoid it.
But what about the aluminum that is already lodged in our bodies? Fortunately, researchers have discovered that a number of natural compounds can reduce the body’s burden of aluminum and prevent or treat its toxic effects. In 8 Ways to Protect Yourself from Aluminum Poisoning, I will examine the many ways we can safely and naturally deal with aluminum toxicity.
Share your thoughts
Are you concerned with aluminum toxicity? What steps have you taken to reduce your exposure to aluminum? Share your thoughts in the comments section below.
 Neurochem Res. 2014 May 3. [published electronically ahead of print]
 Neurochem Res. 2014 May 3. [Epub ahead of print]
Originally published in 2014, this blog has been updated.