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Aluminum is a misunderstood and controversial substance in the natural health community. Some claim it is safe while other sources report that even tiny amounts in baking powder can be harmful. So what is the real story?
Note: This is a long and very science heavy post. Aluminum is a controversial substance and the science is inconclusive, so I tend to avoid it whenever possible. If you’re not interested in the scientific studies surrounding it, skip to the bottom to learn some practical tips on how you can avoid it.
What is Aluminum?
Aluminum is a metal we are all familiar with and a common substance in our daily lives (aluminum foil is one of the most used kitchen items). We find it in household items, vaccines, medications, color pigments, paints, explosives, propellants, and fuel additives. Its oxides are used in household materials and products like ceramics, paper, light bulbs, glass, and heat resistant fibers.
In food, its compounds are used in anti-caking agents, coloring agents, emulsifiers, baking powder (but NOT baking soda), and sometimes soy-based infant formula. (3)
It is important to note that while it is naturally occurring, the body has no need for it (unlike vitamins, minerals and trace minerals). In animal studies, exposure is linked to “behavioral, neuropathological and neurochemical changes.”
In the Environment
Aluminum is the most plentiful metal found in the Earth’s crust, making up about 8% of the Earth’s surface.
Because it is a very reactive element it is never found as a free metal in nature. Instead, it is always bound to other elements such as fluorine, silicon, and oxygen. These compounds are found in soils, rocks, clays, and minerals like sapphires, rubies, and turquoise! It can bind to particles in the air, dissolve in fresh water, and some plants can take it up via the soil. (1, 2, 7)
Human activity increases the concentration of aluminum in our environment. Acid rain can mobilize it from the soil into water, and various industries release its compounds into our air. High environmental concentrations of aluminum can be caused by nearby mines or industries which process and produce aluminum metal, alloys and compounds. Coal power plants and incinerates can also release small amounts of aluminum into the environment. (3, 7)
The average adult in the US ingests about 7-9 mg per day via their food. Whole foods like meat, vegetables and fruits may naturally contain small amounts of this metal since it is a naturally occurring element. Other aluminum compounds may be added to more processed foods in the forms of baking powder, anti caking agents, and coloring agents. (2, 7)
Humans can also be exposed via inhalation and dermal absorption. However, only very small amounts of what we ingest, inhale, or absorb through skin will enter the bloodstream. (2, 7)
It’s estimated that 0.1% to 0.3% of aluminum is absorbed (bioavailable) from the diet, while 0.3% is absorbed via water. Bioavailability is increased when it is ingested with something acidic (like tomato products cooked in an aluminum pan). If not eliminated via the kidneys, it will store in the bones, lungs, muscle, liver and brain. (3)
This is where aluminum gets controversial. While the toxicity is well acknowledged, the debate continues about what levels are considered safe. Most often, acute toxicity is seen in either those who are exposed via their occupational or living environment, or in people who are at risk because they must undergo certain medical treatments.
After contaminated workplaces, living environment, and medical treatments, the next most common source of over exposure is from chronic use of aluminum containing antacids, buffered aspirin, contaminated food, and drinking water. Many health experts counter that the true dangers are seen over a longer period of time and that many studies don’t follow up long enough to reveal long term effects. (3)
Lifestyle Factors Which Can Lead to Overexposure:
- Working in an environment with aluminum dust
- Living in high aluminum areas
– Places near aluminum mines and processing plants (1)
– Living near hazardous waste sites (1)
– Living where it is naturally high in the soil (1)
- Drinking or ingesting substances that contain it
– Often, this comes from chronic antacid use (3)
Health Conditions Which Can Increase Toxicity
Some health conditions make certain individuals more susceptible to aluminum toxicity. Those with reduced kidney function who must receive long term dialysis are exposed to the metal through the dialysate fluid or other medical sources. (3)
However, the incidence of this has declined in recent years with the use of uncontaminated fluid. Even without the contamination from dialysis, since more than 95% of aluminum is eliminated by the kidney, people with poor kidney function are more likely to store it in their bodies. (3,2)
Symptoms of Toxicity
Acute exposure can result in symptoms like: (1)
- muscle weakness
- bone pain, bone deformities, and fractures
- speech problems
- slow growth in children
Diseases of Toxicity
Though medicine often downplays the danger of low-dose aluminum exposure, there is evidence about the dangers of long-term exposure. Known long-term effects of consistent exposure include:
1. Bone Diseases
The evidence is clear, “sustained exposure to high levels of aluminum can cause bone abnormalities.” The metal is deposited at sites of new bone growth. (3)
If aluminum in the body is not properly eliminated by the kidneys or bile, 60% is stored in bone tissue. Increased bone weakness and brittleness are seen in animals exposed to aluminum. These effects can be exacerbated by deficiencies in calcium or magnesium. (3)
Toxicity also leads to the suppression of parathyroid hormone, which regulates calcium homeostasis. In dialysis patients, high levels of serum aluminum (greater than 30 micrograms per liter) have been associated with osteomalacia, softening of the bones, and other related disorders. (3)
2. Nervous System Problems
These problems manifest as difficulty carrying out voluntary and involuntary actions and have a significant correlation to occupational exposure. So called “neuropsychiatric symptoms” include loss of coordination, memory loss, and problems with balance. (3)
3. Brain Diseases and Disorders
Research done on animals, and dialysis patients, make it clear that high levels of aluminum in the CNS can lead to neurotoxicity. In dialysis patients, concentrations of greater than 80 micrograms per liter plasma aluminum, have been associated with encephalopathy (any brain disease that alters brain function or structure).
When exposure comes from I.V. injection 0.001% to 0.01% of the dose enters each gram of the brain. Even with this data, it has been difficult to access what concentration of serum aluminum correlates with brain damage. (3)
4. Respiratory Problems
People who breathe in large amounts of aluminum dusts may develop respiratory problems, such as coughing or abnormal chest x-rays. Most people who develop respiratory illnesses from aluminum do so because their workplaces have high amounts of this dust. (2, 3)
In aluminum industry employees, the most well researched respiratory effect is called Potroom Asthma. The common symptoms of this disorder are wheezing, dyspnea (labored breathing), and impaired lung function. (3)
Other changes seen after occupational exposure are: “alveolar proteinosis and wall thickening, diffuse pulmonary fibrosis, and interstitial emphysema,” along with some nodule formation. Exposure may also contribute to Shaver’s disease, which is a pulmonary fibrosis seen in workers exposed to fine aluminum powders. (3)
5. Impaired Iron Absorption
Aluminum may negatively affect hematopoiesis, the body’s process of creating new red blood cells, especially in persons with an underlying iron deficiency. Interference with the metabolism of other metals has been noted, especially an increased excretion of phosphorous. (3)
Other Possible Health Effects
These are the areas where aluminum exposure gets controversial and there is quite a bit of evidence supporting its possible link to these conditions, though more research is definitely needed.
You may have heard that you should avoid aluminum because it can cause Alzheimer’s Disease. However, the research has come to mixed conclusions.
Before I get into the research results, it’s important to understand how this disease affects the brain.
Alzheimer’s disease, or AD, disrupts metabolic processes that are critical in keeping neurons (brain cells) healthy. These disruptions cause neurons in the brain to stop working properly, lose connections with other cells, and then die.
The death of brain cells is what causes the hallmark symptoms of this terrible disease: memory loss, changes in personality, and the inability to carry out daily tasks. While there is still a lot to be understood about Alzheimer’s Disease, research has identified two abnormal structures in the brains of those with AD: amyloid plaques and neurofibrillary tangles. (4)
Amyloid plaques, first described by Dr. Alois Alzheimer in 1906, consist mainly of insoluble deposits of a toxic protein peptide called beta-amyloid. They are found in the synapses, or spaces between neurons. There is still a lot to be learned about these plaques. It is still unknown whether they directly cause the disease, or if they are a symptom of the disease’s process.
Neurofibrillary tangles are collections of abnormally twisted protein strands found inside nerve cells, and they are primarily made up of a protein called tau. The tangles damage the ability of the neurons to communicate with one another. The next major feature of AD is the loss of connections between neurons. The inhibition of intercellular communication can damage the brain cells and cause them to die off. (4)
As neurons die, the affected regions began to atrophy, and the brain begins to shrink, eventually resulting in death.
Aluminum’s Role in Alzheimer’s
Some studies show that exposure to high levels of the metal do correlate with increased rates of Alzheimer’s disease, while others show no correlation. Exposure from drinking water has been extensively investigated, yet the data is difficult to interpret because of the variety of study designs, and their range of quality. (2, 3)
Still the majority of epidemiological studies have reported a positive association between aluminum levels in drinking water and the risk of AD. This means that when concentrations rose, so did the number of cases of Alzheimer’s. (3)
Research conducted on brain samples have reported that the concentration of aluminum was higher in the overall brain samples, neurofibrillary tangles, and plaques from subjects with Alzheimer’s disease, than the controls. (3)
There are studies which suggest that it has a more indirect role in causing AD. It may amplify conditions and promote mechanisms which have a negative effect by “synergistically” worsening cognitive abilities in Alzheimer’s patients. (3)
One example is that direct injection of aluminum has been shown to increase markers of oxidative stress in animal studies. In animal studies it seems that it may affect levels of cholesterol, which may serve as a potential modulator of Alzheimer-type amyloid formation. (3)
It could increase the aggregation of molecules known to form lesions in the brains of Alzheimer’s patients. One study noted that mice fed diets high in aluminum showed increased levels of amyloid. There is also evidence that it promotes the aggregation of B amyloid peptide in mice (3)
In rabbits, it is well established that exposure to the metal causes the formation of filamentous structures containing cytoplasmic neurofilament protein which would promote the formation of neurofilibary tangles. Even so, in several studies where rats and mice were exposed to very high levels of aluminum, the rodents did not show “profound” cognitive impairment. (3)
In short, this is one area that certainly needs more research, but since the body doesn’t have a physiological need for this metal and there may be a link, it may be worth avoiding until more research can be done.
The evidence is unclear about the effect of aluminum on reproduction, though some animal studies have pointed to an effect on offspring.
When administered orally, it did not seem to affect reproductive capacity in either male or females. Exposure during gestation didn’t affect maternal health or development of the fetuses and neonates.
However, large amounts have been shown to delay the skeletal and neurological development of unborn and developing animals. In one study conducted in mice, neurobehavioral abnormalities were seen in offspring whose mothers were given aluminum during gestation and lactation. (2, 3)
Aluminum is found is breast milk, but only a small amount will enter the infant’s body via breastfeeding. Typical concentrations in human breast milk range from 0.0092 to 0.049 mg/L. (7) It can also be found in soy-based infant formula (0.46–0.93 mg/L) and milk-based infant formula (0.058–0.15 mg/L). (7)
This is another controversial topic when it comes to aluminum exposure.
The Department of Health and Human Services (DHHS) and the Environmental Protection Agency (EPA) have not evaluated the carcinogenic potential in humans, and while it has not conclusively caused cancer in animal studies, some human studies have suggested a possible link between aluminum and breast cancer. (2,3)
Aluminum has been classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC). (3)
A few studies in recent years have theorized that aluminum-based antiperspirants may increase the risk for breast cancer.
According to the authors of these studies, most breast cancers develop in the upper outer part of the breast — the area closest to the armpit, which is where antiperspirants are applied. The studies suggest that chemicals in antiperspirants, including aluminum, are absorbed into the skin, particularly when the skin is nicked during shaving. These studies claim that those chemicals may then interact with DNA and lead to cancerous changes in cells, or interfere with the action of the female hormone estrogen, which is known to influence the growth of breast cancer cells.
Though the direct action of aluminum and its role in breast cancer is not yet definitive or completely understood, it is used as a way to keep the body from perspiring, which may have other negative health consequences, as sweating is a natural process of elimination for the body.
There is also evidence that aluminum creates oxidative stress in the body, which may also increase rates of cancers for this reason. The same negative oxidative effect has been demonstrated in skin cells, and breast cells. This doesn’t prove that it is a cause of cancer but certainly suggests that it is problematic enough to warrant further research and concern.
Aluminum can also bio-accumulate, especially in the brain and substitute for minerals like calcium, magnesium and iron, leading to deficiencies of these minerals.
Items to Avoid
Again, aluminum is a controversial substance and one that hasn’t been extensively studied in long-term human toxicity. At the same time, it isn’t necessary for the body and avoiding it won’t cause any harm, so it is a substance that I personally avoid as much as possible.
If you are concerned and want to avoid aluminum exposure, watch out for these consumer products:
Antacids contain 300-600 mg aluminum hydroxide, which translates to 104-208 mg of aluminum per tablet, capsule or 5mL liquid dose. While little of it will be absorbed it may be a concern for those already experiencing high exposures of the metal or those wishing to avoid it completely. (7)
If a person must take antacids, it is helpful to wait some time before eating anything sour or acidic, such as citrus and tomatoes. Acids make it easier to absorb the aluminum found in antacids. Those who take antacids daily may be experiencing low stomach acid, instead of high stomach acid. (3)
One tablet of buffered aspirin may contain 10-20 mg of aluminum. (7)
Baking powders often utilize sodium aluminum phosphate or sodium aluminum phosphate as a leavening agent. (9)
To avoid, you can make your own using baking soda, arrowroot and cream of tartar.
It is also important to note that baking soda does NOT contain aluminum, though there is definitely confusion about this on the internet. “Aluminum Free” is often used as a marketing term on baking soda packaging, but manufacturers acknowledge that baking soda does not contain this metal and that this is just a marketing ploy.
Aluminum powder is used as a colorant in many cosmetics but mainly in nail polish, eye shadow, eye liner, and lip gloss. It may be listed in the ingredients as: Aluminum, aluminum flake, LB Pigment 5, Pigment Metal 1, A 00, A 95, A 995, A 999, AA 1099, or AA 1199. (5)
Aluminum zirconium tetrachlorohydrex glycine is the form of aluminum used in antiperspirants. It is restricted in Canada. (6) As a simple natural alternative, make your own homemade deodorant with this recipe. (Note: Even “natural” deodorants like crystal deodorants can contain aluminum.)
Many sunscreens, and makeup foundations with sunscreen use aluminum hydroxide as an opacifying agent, skin protectant, and cosmetic colorant. While the Environmental Working Group gives this chemical its lowest hazard score, in Canada it is classified as “expected to be toxic or harmful.” If you’re concerned, make your own sunscreen, use an aluminum-free pre-made version, or use physical measures like hats and shirts to avoid burning. (8)
Aluminum is also present in many other kitchen products like foil, canned goods, water bottles, drink pouches, and tin storage dishes. Research shows that it transfers into food, especially when foods are heated in foil or containers or come into contact with it while hot. Some sources claim that foil is safe for storing cold foods, but I still prefer to avoid it.
Thankfully there are easy substitutes:
- Use homemade wax wrap for covering dishes or get safe food storage containers
- Use a reusable water bottle that doesn’t contain aluminum or plastic
- Buy foods in jars instead of cans (or stick to fresh and frozen!)
- Don’t drink canned drinks like soda
Testing and Regulation
The best way to predict the “aluminum body burden” is to test bone tissue. A blood test is the next best test to access long term exposure, while a urine test is useful to assess if a person has been recently exposed. Another way to test, is to analyze a hair sample, but its value in indicated overall toxicity has not been demonstrated. (3)
Aluminum is currently regulated in food, water and consumer products, though not as tightly in the US as in many other countries.
The Environmental Protection Agency has recommended that a “Secondary Maximum Contaminant Level” or SMCL of 0.05-0.2 mg/L be set for aluminum in drinking water. However this concentration is based on taste, smell, and color; not on if the level will affect the health of humans or animals. (7)
The FDA has determined that the aluminum in food additives and medicinals (aspirin and antacids) is “generally safe”. It has however set a limit for bottled water of 0.2mg/L. (7)
OSHA has set a legal limit for aluminum in dusts (averaged over an 8 hour work day) for 15 mg/m3 (milligram/cubic meter) total dust.
So, Is Aluminum Safe?
Based on this research, I consider aluminum to be a concern. It’s another reason why I am glad I eat unprocessed whole foods and stick to all natural beauty products. Some sources say it is fine, but there is also a body of evidence suggesting it may not be.
1. Mount Sinai Hospital. “Aluminum Toxicity (Aluminum Poisoning).”
2. Agency for Toxic Substances & Disease Registry. “Toxic Substances Portal: Aluminum”. 12 March 2015.
3. Krewski, D., Yorkel, R. A., Nieboer, E., Borchelt, D., Cohen, J., Harry, J., .. Rondeau, V. “Human Health Risk Assessment for Aluminum, Aluminum Oxide, and Aluminum Hydroxide.” 2007. Journal of Toxicology and Environmental Health. Part B, Critical Reviews, 10 (Suppl 1), 1-269.
4. National Institute on Aging. “Alzheimer’s Disease: Unraveling the Mystery.”
5. Environmental Working Group. “Aluminum Powder.”
6. Environmental Working Group. “Aluminum Zirconium Tetrachlorohyrex Glycine Complex.”
7. Agency for Toxic Substances and Disease Registry, Division of Toxicology and Environmental Medicine. “Public Health Statement for Aluminum.”
8. Environmental Working Group. “Aluminum Hydroxide.”
9. Environmental Working Group. “EWG’s Dirty Dozen Guide to Food Additives: Food Additive Watch List.”
Since we still need more research to determine how it affects brain health, I prefer to avoid it. What do you think?