There are so many options for cookware, and it can be confusing trying to navigate what is safe and what should be avoided.
Aluminium cookware has been a heavy topic in the low tox space for a few reasons. There is concern that aluminium, if exposed, could leach into your food when cooking. It has been linked to a number of health concerns, and as such, many people would rather avoid it if given the choice.
Let's look at what aluminium is, where it's found and why it can be considered a cause for concern. You can then weigh out the risk vs benefit and make an informed decision on your next cookware set.
Firstly, what is aluminum?
Aluminum is the most widespread metal on Earth, making up more than 8% of the Earth's core mass. It's also the third most common chemical element on our planet after oxygen and silicon.
The most common form of aluminium found in nature is aluminium sulphates. These are minerals that combine two sulphuric acids: one based on an alkaline metal (lithium, sodium, potassium rubidium or caesium) and one based on a metal from the third group of the periodic table, primarily aluminium.
Aluminium sulphates are used to this day to clean water, for cooking, in medicine, in cosmetology, in the chemical industry and in other sectors. It has no biological role and and is a toxic nonessential metal to microorganisms.
Where is aluminium found?
Human exposure can basically be divided into two categories, “external contact” and “dietary contact”. Dietary contact occurs in a number of ways. For example, aluminium compounds are used within pharmaceuticals; antacids have 300–600 mg aluminum hydroxide (approximately 104– 208 mg of aluminum) per tablet, capsule, or 5 milliliter (mL) liquid dose. Aluminium is also used as a food additive, and it occurs naturally in food. Many unprocessed foods, such as fruits, vegetables, cereal products, and cocoa, inherently contain aluminium. This is thought to be our main source of exposure, with drinking water coming in as our second most common route of exposure.
We are externally exposed to aluminium through cosmetics, and personal care products such as antiperspirants, toothpaste, and sunscreen, from which aluminium can be absorbed either orally or through the skin.
Metal exposures from aluminium cookware can serve as another cause for concern. Eating and drinking utensils as well as pots and pans have been manufactured out of aluminIum since the end of the 1900s. It is known that aluminium can leach into food from a defined surface of the contact material. The Council of Europe passed a resolution for this reason, whereby the maximum amount of metal ions (in mg) allowed to transfer from a defined surface of the contact material to the food (in kg) is 5.00 mg/kg of food.
One study analysed 42 intact aluminium cookware items and tested their potential to release lead and other metals during cooking. The mean exposure estimate for aluminium was 125 mg per serving, more than six times the World Health Organization's Provisional Tolerable Weekly intake of 20mg/day for a 70 kg adult.
Another study analysed the cytotoxicity and genotoxicity effects of water boiled in aluminium cookwares which was then used to grow onions. It found that the onions grown using the water boiled in aluminium pots had disturbed mitosis. Researchers suggested this to be an indicator of the possible health hazards of aluminium cookwares.
Coating the aluminium base has been shown to reduce exposure per serving by >98%, however corrosion of this barrier, therefore exposing the aluminium core, poses a significant health risk.
Once exposed to aluminium how much does our body actually absorb compared to how much is excreted, and what amount is considered 'safe'?
This is always the hard part to determine, because science can show you how much of a substance you have in your body, but can not necessarily attribute it all to one particular source of exposure. For instance, how much of this substance did you absorb through food and water, and how much was absorbed externally from cosmetics or personal care products?
Click here to check out clear tables summarising concentrations and amounts of absorption of aluminium dependent on source.
The European Food Safety Authority (EFSA) report a safe overall intake of aluminium to be 1 mg/kg bw/week.
The World Health Organization's Provisional Tolerable Weekly intake reports safe levels to be 2 mg/kg bw/week.
What happens to aluminium once it's in our body?
After absorption, aluminium is distributed to all tissues. Accumulation takes place in almost all tissues, especially in bones, muscles and kidneys. It is also able to cross the blood brain barrier, and accumulate in the brain (COT 2013; EFSA 2008; JECFA 2012). Like many other substances, aluminium is toxic to brain cells. This is where concern arises, with studies linking toxicity as a result of aluminium exposure and accumulation to neurotoxicity.
What is the health concern?
The possible link between Alzheimer's disease was first put forward in 1965 when it was shown that injection of aluminium compounds into rabbits caused tangle-like formations in nerve cells. However, these experimental tangles differ in structure and composition from Alzheimer tangles in the human brain.
Definitive statements about the role of aluminium cannot be made, and further research is being done on this. These studies are not easy – aluminium is abundant in the environment and exists in many different chemical forms, so exposure is difficult to measure (as explained before).
The Agency for Toxic Substances and Disease Registry summarises the risk of aluminium on human health quite fairly:
Some studies show that people exposed to high levels of aluminium may develop Alzheimer’s disease, but other studies have not found this to be true. We do not know for certain that aluminium causes Alzheimer’s disease.
Without definitive answers, it is my opinion cooking with aluminium should be avoided until it can be determined aluminium absolutely does not contribute to neurotoxicity.
With so many safer cooking options available, why not invest in something that has never been proven to cause human harm, and take away the risk all together.
Some safe cookware options we recommend, include:
- Cast iron
- Enamelled cast iron
- Nickel free stainless steel
- Ceramic (entirely ceramic, not ceramic coated)
- Glass and Corningware
Welcome to the movement,
Chelsea | RN, MCN, Environmental Toxin Expert