Aluminum Guide

Aluminum Information

Is aluminum cookware toxic?

No, not in general (are you surprised!?), but there are shades of grey and some exceptions. Here is a short explanation of each rating symbol above, but I definitely encourage you to read on, as there is a lot more background information about how aluminum affects your health below.

• Non-anodized, for simmering food, if you have kidney disease: the vast majority of aluminum that you’re exposed to passes through the body and is excreted, unless you have kidney disease, in which case it can accumulate in the body. Read more below. Non-anodized means that the aluminum surface doesn’t have a protective oxide layer (simply oxygen attached to the aluminum surface) so more aluminum can leach from the pot or pan surface into your food. Simmering increases the amount of time that aluminum could potentially leach from the pot into your food. This situation would represent the highest chance for aluminum exposure and accumulation in a body.

• Non-anodized, for simmering food, if you’re healthy: non-anodized pots and pans are uncommon in the United States, but if you were to use one, it would mean more aluminum could leach from the pot into your food.

• Anodized, for simmering food: 1-2 milligrams of aluminum may transfer from an anodized aluminum pot into your food (FYI, as you’ll see below, 68 milligrams daily is considered no/low-risk for a 150 pound person, so this is a very small amount.)

• Non-simmering food prep: this would be like an aluminum baking sheet, or using aluminum foil to cover food. Without time, acid, heat, or salt, aluminum doesn’t leach from surfaces into food, and the amount that would transfer to your meal is negligible.

• Touching only: aluminum is very poorly absorbed through the skin — 0.00052% is absorbed into the stratum corneum, the outermost layer of your skin. Even less travels through the stratum corneum to the deeper layers of your skin, where it would have a chance to get into the blood stream. Touching aluminum is not dangerous, and by far the main route of exposure is through eating processed foods or taking certain medications (more on this below.)

Is aluminum foil toxic?

No, not in general. Touching aluminum foil is not dangerous, as essentially zero aluminum is absorbed through your skin, especially when in such short contact. Even using foil to loosely cover food to keep it warm or protected in the fridge would potentially introduce very little aluminum into food.

However, simmering or BBQing in foil may cause leaching of aluminum into your meal, especially if it is acidic or salty. Not cooking in foil is a very easy way to practice the Precautionary Principle, decreasing your overall lifetime exposure to excessive unnecessary aluminum, and staying within the guideline of 1 milligram per kilogram of body weight of aluminum per day (AKA 68 milligrams daily for a 150 pound person), without causing unnecessary stress.

Is aluminum bad for you?

In higher amounts than the body can handle, absolutely, but I’ve really given aluminum a chance to scare me, and — after working in Alzheimer’s, ALS, and cancer research, majoring in biochemistry, going to naturopathic medical school with a very open mind, spending a year in an epidemiology and biostatistics Master’s program, avoiding aluminum-containing anti-perspirants just to be safe for many years, having a high level of concern about everyday toxins in the home, and being skeptical of dismissive advice around exposures— it remains very low on my list of things to avoid. In general, I’m not worried about using aluminum items in the home, and would be more inclined to simply avoid food additives and medications that contain lots of aluminum, and to keep my kidneys healthy and overall inflammation low, so my body can keep not absorbing aluminum— like it was designed to do, and is very good at doing, naturally. Read on to understand why I arrived at this conclusion. Even if you come to a different one, I hope what I share can still help make it easier and less stressful to make decisions about aluminum in your own home.

Where does aluminum come from?

Aluminum makes up 8% of the earth’s crust, and 1.59% of the mass of the earth overall (for a total of 20,940,300,000,000,000,000,000,000,000 pounds!) It is naturally in the air, water, soil, plants, animals, and all humans.

Are we exposed to more aluminum now than before?

Yes, before the Industrial Revolution, we were exposed to a little bit of aluminum daily — just what naturally occurred in the air, water, soil, and our food. Now, we are exposed to more of it for two reasons. First, we’ve extracted aluminum from the earth’s crust because it’s a really useful material, so now it’s used in almost every category of consumer goods— as a food additive, in pharmaceuticals, foil, cookware, bakeware, deodorants, cosmetics, cars, windows, roofing, and many more places. Aluminum is also infinitely recyclable, so the amount of it never goes away. (I’m not exaggerating with my use of infinitely.) Second, we live a lot longer than we used to, so our total exposure and opportunity for aluminum to accumulate in our bodies is higher. This higher exposure level is certainly one of the drivers of concern— are we equipped to handle this much aluminum passing through our bodies this often, for this long?

How does aluminum get into your body?

Almost entirely through eating, especially if you eat highly processed foods or take certain medications. Very small amounts may enter through the other routes of exposure, as well. I think it’s really useful to compare how much comes in from different sources, because it helps put it all in to perspective:

• Ingestion

  • Natural foods: since aluminum is in soil, plants, and animals, the average adult eats 1-10 milligrams of aluminum per day from natural food sources.

  • Food additives: aluminum is used as an anti-caking agent, in food dyes, and in other additives used to make processed food. In 1992, the estimate for an adult that consumes processed food’s daily aluminum intake was up to 95 milligrams daily. My guess is that this number is higher now, considering that food can now be ultra-processed and consumption has risen in the last couple of decades.

  • Nursing: infants consume around 5 milligrams of aluminum from breast milk over their first 2 years of life, or up to 120 milligrams if they’re fed soy-based infant formula.

  • Medicine: if you use aspirin or antacid medications, each dose will typically have at least 100 milligrams of aluminum.

  • Cookware: this is the primary focus for Interior Medicine and the purpose of the rating scale above. If you cook in a standard anodized aluminum pot made in the US, you could ingest an additional 1-2 milligrams of aluminum because heat, salt, and acid can coax aluminum from the pot into your food (a process called “leaching.”) This number will certainly be higher if you’re using non-anodized aluminum pots (not common in the US), or simmering food over a long period of time. Likewise, if you simmer or BBQ food directly in aluminum foil, this number can also be higher, as it’s not anodized (FYI, anodizing is a process of dipping aluminum into an electrolyte bath to create a natural and super-durable oxide layer on the surface, greatly reducing the amount of aluminum that can leach out.)

  • Water: you get about 0.4 milligrams aluminum daily from drinking water. Tap water levels are regulated by the EPA at a maximum of 0.2ppm (parts per million). Aluminum will not leach from your water bottle unless you heat it up or add acidic liquids like orange juice or soda. At normal pH and drinking temperature levels, water does not react with aluminum and coax it out of the walls of the water bottle (AKA it doesn’t leach.)

• Injection: some (not all) vaccines have up to 0.85 milligrams of aluminum per dose. That’s about 1/10th of the amount of aluminum you eat every day. Children on the regular vaccine schedule receive up to 4 milligrams total in the first 2 years of life.

• Breathing: aluminum can be inhaled, because it’s part of soil, and is very light, so floats as dust in the air. You get about 4-20 micrograms of aluminum in your body daily by breathing it in (FYI, micrograms are 1,000 times less than a milligram, so this is a very tiny amount.) If you are an aluminum worker, you are exposed to much more this way.

• Touching: aluminum is very poorly absorbed through your skin, even with direct, prolonged contact, like wearing an aluminum-containing anti-perspirant deodorant. With these deodorants, somewhere between 0.012%, 0.0094%, and 0.00052% is absorbed into the stratum corneum, the outermost layer of your skin (as you can see, there are lots of studies and estimates on this!) Even less travels through the stratum corneum to the deeper layers of your skin, where it would have a chance to get into the blood stream.

How much aluminum accumulates in your body?

Very little, unless you have poor kidney function. The vast majority of aluminum that comes into your body is flushed out. Some numbers: of the aluminum that comes into your gastrointestinal (GI) tract, you absorb 0.1-0.4% of it through the gut lining and into your blood stream, and the rest is excreted in your poop. Of the small percentage that does make it through the gut and into your blood stream, 95% of that is filtered out of your blood by your kidneys and is excreted in your urine (unless you have kidney disease.) Most adults have about 30-50 milligrams of aluminum stored in their body at any given time, mostly in the bones and lungs. Considering you eat at least 10 milligrams every single day, it’s a very tiny percentage that sticks around long term. Great job, body!

Is aluminum a neurotoxin?

Yes, aluminum is a neurotoxin— but only if it actually gets to your brain, which would require that it’s both absorbed into your blood stream and successfully passes through your blood-brain barrier (BBB), which is generally very good at keeping toxins out. If you have severe chronic inflammation, Alzheimer’s Disease, cancer, MS, or Parkinson’s Disease, your BBB may be less good at keeping toxins out, and you might consider being more strict about avoiding aluminum (as well as other exposures.) I think using the phrase “aluminum is a known neurotoxin” as a reason to avoid it completely is a little misleading. It doesn’t give the body’s design or wisdom enough credit.

Does aluminum cause Alzheimer’s?

Almost certainly not. When I started my career (my first “real job” was being a Research Assistant in an Alzheimer’s Disease lab in 2007) I was sure it did, and you can still find a lot of research articles saying it does — but you’ll notice they’re mostly written before 2014, and that there are as many, or even more, research articles saying that aluminum doesn’t cause Alzheimer’s. So what happened in 2014 and how do we make sense of these conflicting articles? The history is super interesting, and I think enormously helpful in understanding it all:

In the early 1900s, although aluminum had obviously been a major part of the earth for millions of years, it started being widely used in consumer products for the first time. In 1913, a dentist from Ohio, Charles Betts, decided that his aluminum utensils were the cause of his gastritis, and he started a nationwide campaign against the metal. (My guess as to why he came to this conclusion is because aluminum was new and unfamiliar, and medicine hadn’t yet figured out that gastritis is usually caused by H. pylori, viral infection, or overuse of alcohol.) He self-published pamphlets and books, and gave talks all across the United States, stirring up the fear that aluminum could cause gastritis and even death. His content was picked up by the Seventh Day Adventists, which published his ideas in their widely-distributed magazine, and by the 1940s, aluminum-free product lines were quite profitable because so many people had learned to fear the metal.

In 1965, researchers found neurofibrillary tangles in the brains of rabbits after they injected those brains with aluminum salts. Neurofibrillary tangles were also in the brains of people with Alzheimer’s Disease, so they naturally wondered whether there was a connection between the two. Very quickly, those same researchers used more advanced staining techniques and learned that it was actually a completely different type of neurofibrillary tangle than the ones seen in Alzheimer’s. Even though their aluminum-Alzheimer’s theory was quickly proved wrong, it hit a nerve in an already aluminum-suspicious public, and this is still considered the beginning of what is known as “The Aluminum Hypothesis.”

In the 1970s, researchers found that people with kidney failure that were receiving dialysis liquid contaminated with aluminum were getting dementia. Without working kidneys to filter it out, the high aluminum blood levels accumulated in the body and eventually crossed the BBB into their brains. Not long after this, the types of cognitive impairments and physiologic changes were found to be a very different type than those seen in Alzheimer’s Disease. Aluminum in the brain is indeed very bad, but it got there because the body wasn’t able to filter it out through the kidneys, and they were receiving very high doses of it. This caused a disease called dialysis encephalopathy which includes cognitive issues, but very different ones than Alzheimer’s Disease. Again, the link was just not there.

In the 1980s and 1990s, most researchers, neurologists, and neuroscientists were moving on from the idea that aluminum caused Alzheimer’s Disease and spent more time looking for other, more convincing causes. But, the fear of aluminum was deeply embedded in both the general public (and some researchers’) minds at this point. Conflicting studies continued to come out— one would show that people with more aluminum in their drinking water had higher risk of Alzheimer’s. Then, another study would be published, finding the exact opposite. In short, there was no consistency in findings. This isn’t because either side was doing a better job than the other— as you’ll see in the next paragraph, it’s because aluminum doesn’t cause Alzheimer’s, just like ice cream sales don’t cause shark attacks, even though they’re perfectly correlated. Something else is going on (in the ice cream sales and shark attacks example, it’s the heat causing people to both buy ice cream and get in the ocean, where there are sharks.)

In 2014, a research paper called “Is the Aluminum Hypothesis Dead?” came out. It used an important set of criteria to convincingly establish that aluminum does not cause Alzheimer’s Disease. It’s called the Bradford-Hill criteria, and if it sounds boring to you, haha, I get it— but I actually think it’s really cool— I learned about it as an Epidemiology student, and it was so illuminating to understand how we can make decisions about whether something truly causes something else, or if it’s time to start looking in another direction. I won’t bore you with the details, unless you want to click through the link above to see them, but zero of the nine Bradford Hill criteria are met (with 60 years of intensive research!!) for aluminum causing Alzheimer’s.

In my opinion, it’s time to release our fear of aluminum and place our energy into finding more likely causes of Alzheimer’s Disease. For the most part, we have, though some researchers still linger on the possibility. I am far more concerned about the 86,000 synthetic chemicals registered for in the United States today, the vast majority of which were invented in the last 100 years and haven’t been tested for their impact on human health, particularly in the complex combinations we’re exposed to them in. The few modern synthetic chemicals we have studied are already showing more consistent, persuasive evidence that they are more harmful to humans than aluminum— BPA and PFAS, for example. I think it’s important for people to be brave and speak out against industries and institutions when there is wrongdoing, and fight for health over profits. But ultimately, based on what I know, I think Charles Betts had gastritis, and incorrectly blamed the “new thing”— aluminum — and that it’s causing unnecessary fear to this day.

Is “Big Aluminum” suppressing evidence that aluminum is related to health problems?

The aluminum industry is huge, and is expected to increase in size and profits over the next few years, mostly driven by car manufacturing. If we were to find out that aluminum was indeed toxic, it would devastate the industry. Aluminum’s novelty and the rapid rise of its use and profits in the early 1900s probably made Charles Betts wary. I think it’s good to have some skepticism around big business like this, and I don’t think you aren’t a conspiracy theorist for considering it. There are many industries that claim their chemicals aren’t harmful— like the (very lucrative) formaldehyde industry does, for example. But, even “Big Formaldehyde” can’t cover up the reality— it’s very obvious that formaldehyde is indeed a carcinogen — every international, US government, and health-related website disagrees with formaldehyde’s website. The PFAS industry is also huge, and was still “taken down” in the last few years as we learned how harmful PFAS really are, particularly through the 3M and DuPont lawsuits. (The PFAS Alternative industry is now growing at a very fast pace as a result.) Finally, the timber industry is even bigger than the aluminum one — it’s estimated to reach a value of $1.2 trillion by 2030. And, wood is a very safe material. Finally, the global wellness industry was valued at $6.3 trillion in 2023, and is rising. The point of all this is, I think it’s good to question enormously profitable industries, but big profits don’t always mean big cover-ups. I still think transparency, science, and public health are more powerful, and I think that is true in the case of aluminum.

Does aluminum cause breast cancer?

No. The story of aluminum possibly causing breast cancer by acting as an endocrine disruptor is similar to the Alzheimer’s story— inconsistent study results in the early 2000s stirred up a lot of fear, but in 2014 a huge systematic review showed zero connection between aluminum-containing antiperspirants and increased cancer risk, specifically breast cancer. A systematic review is not your average research study. It’s considered the best of the best, the highest level of evidence in medicine, as it combines all of the research done on a topic over time to come to a decision. Since then, very little research has been focused on this possibility, as funding and focus has shifted to more likely causes.

What do high levels of aluminum cause then, if not Alzheimer’s or breast cancer?

If you accumulate a lot of aluminum in your body, it’s called Aluminum Toxicity. Normally only seen in elderly renal failure patients, the symptoms of this are anemia, pulmonary fibrosis (stiff lung tissue), decreased bone density, and rigidity and stiffness in movement. It’s treated with aluminum chelation, which uses a medication to speed up detoxification of it from your body.

What about other diseases? Is aluminum bad for you in any way?

Even if you’re convinced that aluminum is not a cause of Alzheimer’s Disease or breast cancer, I think it’s still reasonable, and admirable, to wonder whether “medium” levels of aluminum exposure are bad for you. Is there a spectrum of health issues that aligns with a spectrum of exposures? Sure, low is fine, and high is bad, but what if your exposure falls somewhere in the middle? Or, what if you don’t have kidney disease, but you have another underlying condition with chronic inflammation that compromises your blood-brain barrier or organs of detoxification? Does long term exposure to low levels cause any kind of risk or health problem?

The answer to all of these questions is: it’s possible, but we don’t know yet — research isn’t robust, though there are set limits on aluminum levels in drinking water and for how much we should take in daily. To make sense of this vague and unsatisfying answer, I think our relationship to aluminum should be like the relationship we have with the sun:

• We need a small amount of sun to survive, and our bodies are built to handle a low, healthy amount of sun exposure. Melanin keeps our cells safe. Too much sun exposure, though, and it can, of course, cause skin cancer.

• We also indirectly need aluminum, as it’s in all air, water, and food. Our bodies are built to not absorb it, excrete the vast majority of it, and thrive even if we have accumulated a small amount. Too much, though, can of course cause alumninum toxicity.

I think this sun-like relationship with aluminum is a much smarter approach than having a lead-like relationship with aluminum. Aiming for zero lead exposure is a very good idea. No level is safe. But that’s just not true with aluminum, and the same logic can’t be applied.

How strictly should I avoid aluminum?

The best way you can reduce your exposure to aluminum is by reducing how much you ingest, since so little enters through the other routes of exposure, including skin contact. The majority of ingested aluminum comes from food additives, processed foods, and medications that contain aluminum like antacids. If you missed the section above on how much aluminum is in different things, scroll up to see the list!

How much aluminum is safe?

The Minimal Risk Level, meaning, at this level, there are no known health effects, is 1 milligram per kilogram of body weight of aluminum per day. For a 150 pound person, that would mean 68 millgrams or less of aluminum daily. Scroll up to see the list above of how you might get to that level on a daily basis.

What is hard anodization?

Hard anodization forms a protective oxide layer on cookware so that reactive metals like aluminum won’t be in direct contact with acidic foods like tomatoes, causing breakdown. The process of hard anodizing involves the pot or pan being submerged in a cold electrolyte (salt) bath, and having an electric current run through it, producing a durable oxide layer. It’s much safer than a non-stick chemical coating, and is generally considered safe for people. However, the process can be bad for the environment, which is why some brands advertise that they don’t use it.