Aluminum Foil: Unwrapping potential risks

Enhance your summer BBQs with healthier cooking methods. Learn about the best alternatives to aluminum foil and discover tips for delicious, safe, and worry-free grilling for your family and friends.

As we gear up for those sizzling summer BBQs and July 4th celebrations, let’s take a closer look today at one essential tool in our outdoor (and let’s be honest, indoor too) cooking arsenal: Aluminum Foil. 

While it may seem like a convenient solution for wrapping up your favorite foods on the grill, the truth is that cooking with aluminum foil can pose risks that you should be aware of. 

A few years ago, I was shocked to learn that aluminum in cookware doesn’t just stay in the cookware: People who use aluminum cookware/utensils at home have twice as much aluminum in their blood as people who don’t… what’s more - the aluminum is not exactly benign - it caused oxidative damage to white blood cells in the blood samples they took for the study.¹

Can aluminum really leach from aluminum foil into my food?

Yes. This has been shown in several studies now, and we will talk about factors that increase the leaching below so you know how to protect yourself if you do use it.

One study found aluminum content increased by 20 times after marinating and heating salmon and mackerel samples wrapped in aluminum foil.² Something millions of Americans will be doing in the coming week for those July 4th BBQs.

Aluminum is a ubiquitous heavy metal in our environment, and is deemed safe in small doses (thank you detox organs for eliminating unavoidable exposures for us!).

Unfortunately, most Americans are exceeding those ‘safe’ doses. When this happens, aluminum may accumulate in the body and lead to health issues years down the line.

What is a safe ‘dose’?

The World Health Organization (WHO) recommends a daily aluminum intake of no more than 2 mg/kg of body weight.³

But according to the ATSDR, the average American consumes 7-9mg of aluminum per day from food, and the average intake reaching 50-1000 mg per day (!!!) in the case of drug administration (e.g. aluminum-containing antacids like Mylanta).⁴⁵

How can this be? 

Sadly, we have polluted our earth extensively through industrial processes, and we are now exposed to aluminum via the air, drinking water, food, supplements/medications, and cookware/utensils. 

So the question is not ‘IF’ we are exposed to aluminum, but ‘how much’, and how can we stay healthy despite constant exposures - what this whole community is about!

Health impacts of Aluminum & how to mitigate

Now, before you panic - we don’t know what these high levels of aluminum intake translate to in terms of harm to our health - so far, we have petri dish and animal studies showing aluminum to be a neurotoxin and can damage kidney cells too.

Observational human studies have also shown some concerning associations.

Here are some of the health risks associated with aluminum so far:

1. Oxidative Stress: Think of this as ‘rust’ (which damages metal). Like rust, oxidative stress damages our cells and leads to inflammation, which underlies many chronic diseases from type 2 diabetes to heart disease and neurodegenerative conditions like Alzheimer’s disease. 

2. Potential Link to Alzheimer's Disease: While the link between aluminum and Alzheimer's disease remains controversial, a meta-analysis involving over 1200 patients suggested that people with Alzheimer’s disease have higher aluminum in the brain and the cerebrospinal fluid (the liquid that surrounds the brain).⁶ Whether aluminum leads to Alzheimer's, or the disease process of Alzheimer’s leads to the deposition of aluminum in the brain is still hotly debated and we need more studies to help us decipher which is the chicken and which is the egg. 

3. Inflammatory Bowel Diseases: Some researchers have proposed a potential association between aluminum exposure and inflammatory bowel diseases like Crohn's disease.⁷ Aluminum's ability to induce oxidative stress and inflammation may underlie this but we don’t have causal proof yet. 

4. DNA Damage: High levels of aluminum exposure have been shown to cause DNA damage in occupational settings, which can lead to mutations and increase the risk of various downstream health conditions.⁸ 

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Factors Affecting Aluminum Leaching

If we know what can increase the leaching of aluminum from foil into food, then we can take steps to reduce it.

1. Higher cooking temperatures. Here’s what studies have shown:

   1. “During baking of food wrapped in aluminum foil at lower temperatures (<160ºC), the leaching of aluminum is at a lower rate than when the process of baking is done at temperatures over 220ºC”.⁹ 

   2. Cooking temperature is more influential on leaching than cooking time. One study compared cooking meat wrapped in aluminum foil for 60 min at 150°C, 40 min at 200°C, and 20 min at 250°C. 20 min at 250°C showed the highest aluminum after cooking (increase by 153–378%). (Raw meat obviously showed the lowest).¹⁰ 

Why does this happen? “Higher cooking temperatures render the oxide layer thicker and change it from an amorphous to a crystalline structure, allowing easier transfer into food.”¹¹ 

2. Acidic Foods¹²  Foods like fruit juice can leach 2.9-35 mg/kg, berries 19-77 mg/kg, and particularly rhubarb 170 mg/kg when boiled for 60 minutes in aluminum cookware.