Health Science

Higher Concentrations of Aluminum in the Brains of Those With Alzheimer’s, Autism, and MS

The metal accumulates in the body and brain with dangerous consequences, but there are things you can do
BY Jacquelyn Waters TIMEJune 21, 2022 PRINT

The human body is an electrochemical miracle. While we often think of it as a fleshy machine of sorts, it can be more likened to a constantly changing collection of chemicals and electrical signals that’s continuously rebuilding itself and responding to your mental state, food, air intake, physical activity, and environment.

This biochemical landscape of the human body is in delicate balance. An unfathomable series of reactions transforms the molecules of the food you eat and the air you breathe into the components of your body and the energy that fuels it.

Aluminum upsets the ebb and flow of a number of key molecules that play critical roles in balanced systems within the body, leading to serious health complications.

How are we exposed to aluminum? Is it really affecting our bodies? How can we protect ourselves?

Routes of Aluminum Exposure

Aluminum is the most abundant metal in the crust of the Earth. It has beneficial properties important to many industries.

Aluminum weighs much less than steel, and it’s easily machined, durable, and resistant to corrosion. It can conduct electricity well and can be recycled many times over. The aluminum industry is massive and growing.

And while individuals involved in aluminum processing often experience increased exposure to aluminum, particularly if they make aluminum powder, the metal has found its way far beyond industrial uses. It’s now found in everything from cosmetics to food.

Aluminum in Food

For most individuals, food is a main source of aluminum exposure and may contribute to as much as 95 percent of aluminum concentration in the body, according to a research review article published in the French journal Médecine et Maladies Infectieuses.

Many fruits and vegetables naturally contain small amounts of aluminum.

Of bigger concern are processed foods that include aluminum as an approved food additive.

Salim Saiyed and Robert Yokel of the University of Kentucky used spectrometry to quantify the amount of aluminum in some commonly eaten processed foods. They found that the aluminum content in the foods they tested ranged from 1 to 27,000 milligrams of aluminum per kilogram of food.

Their study, “Aluminium Content of Some Foods and Food Products in the USA, With Aluminium Food Additives,” was published in the journal Food Additives & Contaminants in 2005. Aluminium is the British spelling of aluminum.

In the study, cheese tested from frozen pizzas had as much as 14 mg of aluminum per serving. The aluminum came from sodium aluminum phosphate, an FDA-approved food additive. The same amount of cheese in a restaurant pizza had less than 1 mg of aluminum.

Saiyed and Yokel found that sodium aluminum phosphate was present in many food products. Baking powder, ready-to-eat pancakes, and several pancake and waffle mixes had the most aluminum out of all the foods tested. Some of these foods had up to 180 mg of aluminum per serving.

The researchers note that in many other countries, aluminum intake through dietary consumption does not typically exceed 12 mg per day. Americans who are consuming processed foods are likely ingesting much more aluminum than this.

Aluminum in Water

Aluminum is not just in processed food; it can leach from soil and rock into water sources. In fact, aluminum’s prevalence in the Earth’s crust means it’s found in all natural waters.

But beyond naturally occurring sources, aluminum sulfate is often used in water treatment plants as a coagulant. If the coagulation process doesn’t proceed properly, aluminum concentrations in tap water may be elevated, notes a 2020 research article on residual aluminum in drinking water and its effects, published in the journal Molecules.

Low molecular weight polyaluminum species left over in the water are chemically reactive and may be more easily absorbed into the human body. Treating water with aluminum sulfate is known to increase the amount of these low molecular weight species, notes a 2019 research review published in Chemosphere.

Other Sources of Aluminum

It’s well-known that antiperspirants contain aluminum. The metal is also found in cosmetic, hygiene, and hair products. Sunscreen frequently contains aluminum, as it prevents titanium dioxide particles from clumping.

Certain antacids, such as Maalox, contain aluminum hydroxide. Long-term use of these contributes to an increased aluminum load in the body.

Aluminum hydroxide is also used as a dye in the coating of some buffered aspirins. The dye FD&C yellow #6 aluminum lake is one example.

In the medical industry, injectable preparations may contain aluminum. Parenteral nutrition solutions are used to provide nutrition to patients who cannot efficiently absorb nutrients through their small intestine.

FDA regulation 201.323 limits the amount of aluminum allowed in these products, stating that it may not exceed 25 micrograms of aluminum per liter.

The regulation requires that a warning be inserted in all these products that includes the following: “Research indicates that patients with impaired kidney function, including premature neonates, who receive parenteral levels of aluminum at greater than 4 to 5 [micro]g/kg/day accumulate aluminum at levels associated with central nervous system and bone toxicity. Tissue loading may occur at even lower rates of administration.”

This means that for a premature baby, a toxic dose of aluminum would be approximately 8 to 28 mcg.

The Recombivax HB (hepatitis B vaccine), given to newborns, contains 250 mcg of aluminum adjuvant, according to the National Institutes of Health.

If a premature baby cannot tolerate more than 28 mcg of aluminum at most, can we assume all full-term newborn babies will be able to handle a 250 mcg aluminum load without adverse effects?

In addition to the hepatitis B vaccine, other vaccines that contain aluminum include the DTaP (diphtheria, tetanus, and acellular pertussis) vaccine, some influenza vaccines, pneumococcal conjugate vaccine, Tdap (tetanus, diphtheria, and pertussis) vaccine, hepatitis A vaccine, and Gardasil’s HPV (human papillomavirus) vaccine.

Where Does Absorbed Aluminum Go?

After it’s absorbed, aluminum is distributed widely to various tissues. Some of the aluminum is excreted in the urine, so long as the individual doesn’t have kidney disease. The aluminum that isn’t excreted accumulates in the bones, liver, lungs, and brain, according to the Médecine et Maladies Infectieuses review.

Accumulation of Aluminum in Bones

Most of the aluminum that gets absorbed binds to the transport protein transferrin, notes a case report published in the Journal of Pediatric Gastroenterology and Nutrition.

Transferrin is created by the body to bind iron and carry it throughout the body. Iron is particularly important in bone homeostasis.

While the transferrin would typically transfer iron to bone, the presence of absorbed aluminum causes the protein to transfer aluminum instead. It’s well-documented that aluminum accumulates in the bone tissue of those with chronic kidney disease and in patients receiving long-term parenteral nutrition due to intestinal issues.

Your bones are constantly breaking down old bone material and creating new bone material. The specialized cells that build new bone are called osteoblasts. These cells create collagen and other proteins, then mineralize the surrounding matrix to form new bone.

In bone growth, the area being constructed has a face called the mineralization front. At this front, osteoblasts lay down new collagen fibers and calcium is accumulated there.

In aluminum-based bone pathogenesis, aluminum preferentially binds to the unmineralized collagen. The result is impaired bone mineralization and a condition of weakened bone tissue, called osteomalacia.

Another way aluminum toxicity affects bone health is by decreasing the activity of 5-hydroxyvitamin D-1 alpha hydroxylase, a finding dating back to at least 1985. This enzyme is produced by the kidneys and converts 25-hydroxyvitamin D into a more potent metabolite called 1,25-dihydroxyvitamin D (cacitriol), which we know as vitamin D.

Vitamin D facilitates the absorption of calcium from the intestine into the bloodstream. More pronounced vitamin D deficiency can result in hypocalcemia. The result may be a loss of bone density, leading to osteoporosis. Bones may become weak and brittle enough that they break easily.

Accumulation of Aluminum in the Brain

While aluminum accumulation in the bones is concerning, what is more alarming is aluminum accumulation in the brain. Post-mortem studies have found the presence of aluminum in the brains of deceased individuals.

When aluminum-bound transferrin reaches the blood-brain barrier, it binds to transferrin receptors. These aluminum-transferrin receptor complexes are then brought into cells associated with the blood-brain barrier.

Once in the brain, clearance is minimal without chelation therapy, the Médecine et Maladies Infectieuses study notes.

There’s no known biological role for aluminum in the brain. It’s not part of normal brain biochemistry. Instead, aluminum is highly disruptive to a large number of metabolic pathways in the brain. Decades of research reveal that aluminum is neurotoxic. What is unclear is how much aluminum is too much. For example, is the concentration of aluminum in the brains of individuals with Alzheimer’s disease, multiple sclerosis, or autism spectrum disorder higher than in individuals who don’t  have any of these conditions?

Researchers Christopher Exley at Keele University in the UK and Elizabeth Clarkston at Wichita State University in Kansas sought to answer this question in their study “Aluminium in Human Brain Tissue From Donors Without Neurodegenerative Disease,” published in the journal Scientific Reports in 2020.

The analysis included 191 tissue samples from 20 control brains. The control donors had no diagnosis of neurodegenerative disease.

Exley and Clarkston compared the control data to samples of brain tissue from donors who had a diagnosis of Alzheimer’s disease (12 patients), multiple sclerosis (14 patients), and autism spectrum disorder (five patients).

Notably, all three disease groups had significantly higher brain content of aluminum. This held true for any statistical analysis that was applied.

Further, all the studied disease groups had the “characteristics of significant focal deposits of aluminium throughout all main lobes of the brain and associated neuropathology and neurodegeneration,” the researchers wrote.

Interestingly, increased aluminum content was not associated with increased age. These data suggest that perhaps aluminum accumulation in the brain is not an inevitable part of aging.

While the study doesn’t give the mechanism of toxicity, it implicates aluminum in these particular neurodegenerative diseases.

In vitro cell studies reveal the mechanisms by which aluminum disrupts the delicate metabolic pathways in the human body. Researchers are also able to reproduce several neuropathologies of human neurodegenerative disease in animal models by exposing them to aluminum.

All of these studies give us a bigger picture of the role aluminum plays in brain pathology. The current data on the molecular dysregulation of healthy cells by aluminum toxicity are vast.

To summarize numerous research studies, aluminum exerts its toxic effects through mitochondrial dysfunction, and inflammatory, prooxidant, and proapoptotic pathways. These pathways have been reported in a number of tissues and cell lines.

One recent study by scientists at the Zhejiang Provincial Center for Disease Control and Prevention demonstrates a significant association between exposure to aluminum and lower cognitive function.

Protecting Yourself From Aluminum Toxicity

Exposure to aluminum is unavoidable, but there are ways to protect yourself from the toxic effects.

First, certain trace elements are protective.

Studies published in the Journal of Alzheimer’s Disease (2013) and the Journal of Trace Elements in Medicine and Biology (2014) demonstrate that the adverse neurological effects of aluminum may be prevented by consuming more silicon. Silicon forms aluminosilicate in the body, thus decreasing the amount of free aluminum available to damage cells.

Silicon occurs naturally in the form of silica, which is a transparent compound found in many rocks and in water. Certain water sources have higher amounts of silica than others. For instance, water obtained from artesian wells in Fiji (bottled by Fiji Water) has a significant amount of silica. Unfortunately, many other kinds of bottled drinking water, such as Aquafina, are produced using reverse osmosis, which removes naturally occurring silica.

Selenium, another trace element that helps to protect against aluminum neurotoxicity, is a component of glutathione peroxidase, one of the most important antioxidants produced by the body.

Glutathione is biologically effective when it’s in its reduced form. The enzyme glutathione reductase is essential for replenishing the reduced form of glutathione in cells.

In one study, rats treated with aluminum chloride showed a decrease in glutathione reductase activity and a decrease in reduced glutathione levels. Treatment with selenium markedly reversed these biochemical changes and improved brain morphology. The researchers involved in the study, published in Biological Trace Element Research in 2015, stated that their findings bolster the hypothesis that selenium is useful in combating the oxidative stress caused by aluminum in the brain.

In another study, researchers exposed mice to aluminum, then fed a cohort of them yeast with a high selenium content. The mice were then assessed for inflammatory biomarkers and pathology. The data, published in BioMetals in 2018, demonstrate that high selenium ingestion decreases aluminum-induced cerebral inflammation.

A third trace element shown to ameliorate the negative effects of aluminum in the brain is zinc. In a study using rats published in BioMetals in 2015, zinc supplementation was found to increase reduced glutathione levels and reverse aluminum-induced neurodegeneration.

These same researchers found that zinc has an antiapoptotic effect (prevents cell death) in aluminum-exposed animals.

In addition to these trace elements, eating a diet high in polyphenols helps to protect you against the toxic effects of aluminum. Polyphenols are antioxidants that can be found in fruits, vegetables, and whole grains.

Finally, chelation therapy, which uses special supplements and drugs to bind metals in your body and remove them through excretion, can help to protect you.

Ethylenediamine tetraacetic acid (EDTA), a synthetic solution used in chelation therapy, has been shown to be effective in decreasing aluminum neurotoxicity, according to a study published in the Journal of Inorganic Biochemistry in 2015.

Zeolites, also used as chelators, are porous minerals with numerous cavities and molecular channels. In nature, these cavities are filled with positively charged ions, such as sodium, magnesium, and calcium.

Zeolites are known for their excellent ion exchange properties—the zeolite can release the sodium, magnesium, and calcium, and take in metal cations (positively charged ions or a group of ions) such as aluminum. The metals settle in the zeolite cavities, and the zeolites pass easily through the kidneys, allowing the metals to be excreted out of the body.

The main zeolite used for medicinal purposes is a natural zeolite called clinoptilolite.

Natural and synthetic zeolites do a good job of removing heavy metals in vitro, and clinoptilolite supplementation is associated with a decreased concentration of aluminum in blood plasma, bones, and liver in animals exposed to aluminum, according to research published in ​​Microporous and Mesoporous Materials in 2017.

While we can’t completely avoid aluminum, eating foods that are not highly processed is one powerful way to protect yourself from aluminum overload. Another way to protect yourself is to eat a diet high in fruits and vegetables. Supplement with selenium and zinc, and drink some Fiji water each week. Read the labels on your lotions, sunscreens, and other personal care products. Avoid antiperspirants with aluminum. Finally, consider working with your doctor to find a quality EDTA or clinoptilolite product and complete a chelation regimen.

Jacquelyn Waters writes about health, science, and medicine. She has particular interest in all things neuroscience—from molecular neuroscience to psychology. She has 8 years of experience teaching college biology and received her Master’s degree in biomedical sciences with a specialization in neuroscience from Vanderbilt University.
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