Beware of Cookware
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Lead to Death
In the 18th Century, Europeans called tomatoes “poison apples”, because the few people who got to eat them got sick (or even died) not long after.
Now, nothing was different about tomatoes back then. They were as delicious as they are today. So, why were some unlucky bourgeois dropping dead after eating them?
Interestingly, the answer lies not hidden inside the tomatoes themselves… but right underneath them. The problem was not their food: it was their plates.
Late Victorian people did not know any better, so the plates and cookware they used on a daily basis were often full of toxic heavy metals—especially lead. This did not cause immediate problems most of the time... until they started eating corrosive foods on top of them.
That's right: the acidity of tomatoes reacted with their pans, pots, plates and cutlery, and cascaded a stream of heavy metals into their ignorant bodies. What the bourgeois thought was a delicious (albeit slightly metallic) dish was, in reality, their last meal on nature's secret death row.
Now, I’m well aware that most of us today don't have to worry about a sudden early trip to the grave just for eating tomatoes.
But given that most of our relationship with food unfolds in or around kitchens, we should be conscious of the unnecessary toxins and life-inhibitors that even seemingly “safe” and “modern” equipment hide.
What Not to Use
Non-Stick Cookware
Non-stick pans are as convenient as they are harmful.
Much to the chagrin of companies like DuPont which, for decades, tried to suppress evidence of the harmful effects of their cookware, it is now clear as day that non-stick pans and pots are wreaking havoc in your system.
These non-stick materials are made up of per- and polyfluoroalkyl substances (PFAS), a group of over 9,000 plastic chemicals which have been linked to a myriad of health problems. PFAS are also sometimes referred to as PFCs (perfluorinated chemicals). [1.1-5]
The molecular structure of PFAS includes strong carbon-fluorine (C-F) bonds, which makes them highly resistant to degradation by environmental factors such as heat, light, and microbial action. This is why they are often called "forever chemicals": because they do not break down easily in the environment.
PFAS are used in a wide range of industrial and consumer products due to their unique properties. Most notably, they are used in the production of non-stick cookware (e.g., Teflon), water- and stain-resistant coatings for fabrics and carpets, food packaging, firefighting foams, and more. If it makes things slide easily, it probably has PFAS in it.
Because they have been used everywhere since the 1940’s, and because they are so damn persistent, they have made their way deep into our bodies. PFAS have been found in the breast milk of 98% of Korean women and the blood of 97% of Americans. [1.6-7]
Initially, the PFAS of choice were perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), until authorities worldwide banned them over the last decade for causing mammary, testicular, pancreatic and kidney cancer, early puberty, immune system problems, liver damage, thyroid disease... you get the idea. [1.8-1.10]
Chemical manufacturers did not give up though. After their ban, they started using other PFAS—even giving them cool names like "GenX"—to keep banging out non-stick stuff. [1.11]
PFNA, PFHxS, PFHxA, PFDA, PFBA, PFBS... you can pretty much type any combination of letters after PF and you'll get a substance aching to tank your sperm production, mess up your thyroid, prevent proper ovarian function, cause cancer, and (literally) shrink your penis, as a study found that “subjects from the exposed group showed significantly lower mean testicular volume and shorter penile length [...] after adjustment for multiple comparisons.” [1.12-15]
Known effects of PFAS on human body
So, as convenient as non-stick cookware may be, I think we should limit its use. There are way better options for daily cooking, which we will cover shortly.
Take-aways:
Don't use them.
Aluminum Cookware
Although aluminum is generally thought to be safe because of its "modest" leaching levels and "weak" evidence of its connection to Alzheimer's, I won't recommend it. [2.1]
Aluminum is a lightweight, silvery-white metal used in a myriad of things, from soda cans to airplanes, because it's strong, doesn't rust, and is easy to recycle—but it’s not impervious to leaking.
Brewing coffee in an aluminum pot has been shown to dissolve large amounts of aluminum into the drink, and the metal—like all heavy metals—is known to accumulate in our tissues over time (no bueno). A similar reaction takes place when cooking acidic foods like tomatoes in aluminum pans and pots. [2.2]
Aluminum makes you generate increasingly excessive amounts of reactive oxygen species (ROS)—a usual byproduct of cellular respiration—which can inhibit your metabolism by causing damage to your cells ability to produce energy (we explain a bit further what ROS are in the chapter on EMR). [2.3-4]
Plus, according to the European Food and Safety Authority, some of the most common food additives (E523, E541, E554, E556 and E559) include plenty of aluminum, which causes most people to already exceed the maximum weekly safe intake by 2 or even 100+ times, depending on their lifestyle. [2.5]
So, whilst aluminum manufacturers might tell you their products are very safe—especially when compared to those with Teflon—they most likely aren’t.
Take-aways:
Don't use them.
What to Use With Caution
Ceramic Cookware
Ceramic cookware is tricky, because most of the products on the market are not made of pure ceramic.
Whether talking about traditional ceramic crock pots or more modern iterations (like the ones in the picture above) the dangers are the same: heavy metal contamination.
Even if the ceramic itself does not contain lead, ceramic cookware is often "glazed" with a protective cover that does, which in one famous case sent a woman to the hospital (more on protective “glazes” in the following subsection). [3.1]
As you already know by now, the consequences of lead contamination are endless and, unlike with other heavy metals, there is basically no safe amount of lead a person can have in their blood.
Lead's chemical structure is similar to that of calcium, which tricks your body into storing it in your bones for years to come, unless you begin some sort of chelation/detox therapy.
X-ray of lead deposits on human bone
Most importantly, modern ceramic cookware, even if heavy metal-free, is very expensive and particularly fragile, so I don't really see any reason to go for it over our upcoming solutions. Browsing through reviews on Amazon I got the impression that many ceramic sets, regardless of how expensive they were, weren’t particularly durable in relation to their price.
I believe the same holds true for clay cookware, by the way.
Take-aways:
If you have no idea where the ceramic comes from, don’t use them.
If you do and are 100% sure it is free of lead and other heavy metals, then it is a safe (albeit expensive) choice.
Enamel-Coated Cookware
Enamel is a durable and glossy material that is often used to coat various objects, including cookware, for both functional and aesthetic purposes. It is a type of glass that is fused onto a metal surface, typically steel or cast iron, through a high-temperature firing process.
Thus, enamel glazing provides a smooth and non-stick surface, making it easier to cook and clean. It also adds a pop of color to the cookware.
Unfortunately, as it is the case with ceramic cookware, some enamel products are known to leach heavy metals.
In 2018, the German Federal Institute for Risk Assessment published a study on the migration of heavy metals from enameled grill grates and, according to their findings, significant quantities of aluminum, antimony, arsenic and nickel were found to be released from some of them. [4.1-2]
I’m certain this will depend on what material is being coated in the first place, but once again, even if heavy-metal free, some enamel cookware can be very expensive, so I won’t actively recommend it over those in the following section.
(I’ll agree some enamel cookware looks amazing though, so if you can afford it and take good care of it, you’ll likely be more okay.)
Cast-Iron Cookware
Cast-iron skillets are usually hailed as the alternative to non-stick.
They have a long tradition in Europe, can last for generations, sear steaks fantastically, and have the added benefit of providing extra iron… which is why I won't recommend them for daily use. [5.1]
There is reason to believe that, just like with aluminum, most people today consume too much iron. This applies even to those diagnosed with anemia.
“The real issue is that you can hardly avoid getting iron, even when you try [...] Iron-deficiency anemia does exist, in laboratory situations and in some cases of chronic bleeding, but I believe it should be the last-suspected cause of anemia, instead of the first.” - Dr. Ray Peat [5.2]
In the U.S., iron is added to most types of grains by a naïve and outdated federal law, often in its most reactive, least bioavailable (metallic) form. [5.3]
I'm sure you've seen videos of people crushing cereal and moving the added iron with a magnet:
The problem lies not in our intake of iron, but in how we metabolize it. When our bodies don't process iron properly (e.g., by binding it to a specific protein), or when we intake a non-bioavailable form, it becomes serious trouble.
Unbound iron can destroy your metabolism and thus cause a long list of "endocrinological, gastrointestinal, infectious, neoplasmic, neurodegenerative, obstetric, ophthalmic, orthopedic, pulmonary and vascular" diseases. [5.4-5]
Take-aways:
Don't use them for daily cooking; save them for special occasions (e.g., an amazingly seare steak), or if you are actually iron-deficient anemic, which is different from just being anemic.
Make sure you season them extremely well, as that will reduce the leaching of iron into your food. And please, do so with ghee or beef tallow—not with PUFA-ridden oils.
What to Use Daily
Stainless Steel Cookware
Okay, so what about stainless steel? Is it safe to use?
Yes. But there’s a catch. Let me explain.
Stainless steel products are not 100% steel. Most of the time, they are made of a metal alloy with added chromium and nickel (amongst other things), which makes the steel shinier, more resistant to corrosion, etc.
You will often see stainless steel products being described as 18/8 or 18/10. The first number refers to the percentage of chromium, and the second to that of nickel. So, an 18/8 stainless steel is 18% chromium and 8% nickel.
The problem with these types of stainless steel is that—you guessed it—they are known to leach both chromium and nickel into your food... And I don't think I need to mention once more that, as heavy metals, they can cause trouble in the long run. [6.1-2]
Nickel in particular is most concerning. If you have a nickel allergy (which is not uncommon), cooking with it could be causing skin issues (e.g., dermatitis). It is also known to have harmful “gastrointestinal, hematological (blood-related), and neurological” effects. [6.3-4]
Chromium exposure is not that big a deal as far as I can tell, especially considering we do need a tiny amount of chromium for certain metabolic processes, though the science on this is not entirely clear. [6.5]
So, what can we do about this? Simply get a stainless steel set without nickel? Something like an 18/0 stainless steel?
Not so fast. Let me explain.
You might have heard that it is useful to check whether your stainless steel cookware is made from "good stainless steel" by checking if it is magnetic (using a fridge magnet on it). If it is magnetic, it is said to be good; if not, it is said to be bad. This is because when metals like nickel are added into the mix, the steel becomes austenitic, which makes it non-magnetic (or weakly so).
Alas, there are two problems with this popular advice:
(1) Most people forget to check whether all surfaces are magnetic or not.
If you simply stick a fridge magnet onto the back of a stainless steel pan, it will more often than not do so very firmly. But this is not a testament to its high quality; rather, most bases are strongly magnetic because they need to be so in order to work on induction stoves.
If you were to check the inner layer (the one that has contact with food) you would find the magnet often fails to stick, or does so very weakly.
(2) As we mentioned earlier, nickel-free stainless steel is much more susceptible to corrosion.
This means your cookware will not last as long.
And it also means that, as it gets used up, it will leach more and more iron into your food, as has been shown by the Finnish Institute of Occupational Health. [6.6]
Notice how 300-series pans (those containing nickel) leach a bit of nickel and a bit of iron, whereas the 400-series ones (without nickel) leach no nickel—obviously—but plenty of iron.
So, when it comes to stainless steel, it seems to me like we need to make a choice:
Do we opt for the nickel version and risk it leaching nickel? Or,
Do we go for the nickel-free one and risk more iron leaching and corrosion in the long run?
Here's what I would do.
(1) I would buy very high-quality 18/8 or 18/10 cookware, something from a reputable brand and a good warranty.
There is a lot of inconsistency among studies, and much of it can simply be attributed to differences in manufacturing quality. In a particular study, leaching levels were "remarkably different between manufacturers." Two 18/10 stainless steel pans could leach significantly different levels of heavy metals, depending on their built quality. [6.7]
To give a quick example:
This lady boiled a cup of vinegar in water in two nickel-containing stainless steel pans: one high-quality (All-Clad brand), one low-quality.
After a couple of hours, she reports that the vinegar in the high-quality brand tasted like normal vinegar, but that the one in the low-quality brand tasted terribly metallic.
(2) Then, I would "pre-leach" most of the heavy metals before I used it, by boiling a cup of white vinegar in water for a few hours a few times (e.g., 3 x 3 hours).
Here’s the thing:
Yes, stainless steel leaches, but most of the leaching happens in the first cycles of cooking, particularly when acidic foods are used. This is a bit counterintuitive. How come the more we use it, the less nickel it leaches? Are we simply “taking away” the nickel from the surface?
Not exactly.
By cooking low pH (acidic) foods, we are reacting with the chromium in the steel alloy and creating a chromium oxide layer that will inhibit further leaching of nickel. We are “sealing” the steel, so to speak, which dramatically reduces nickel leaching. So, we can use this to our advantage.
The study above showed the leach of nickel and chromium content dropped to its minimum after 6 cooking cycles of 6 hours each.
I know this is a huge hassle—and simply not realistic whatsoever—but I reckon even a few cooking cycles would prevent the bulk of the leach from going into your food.
So, to sum up, given that:
Stainless steel is subject to leaching,
Manufacturing quality matters, and,
We can get rid of most of the leaching in the first cooking cycles, then…
I reckon going for a high-quality 18/10 or 18/8 stainless steel pan is a good safe option, especially if you "pre-leach" it.
As for the remaining metals that will still leach, well… maybe you can take refuge in knowing most of your consumption is likely to come from heavy-metal intoxicated foods anyway (particularly legumes, cereal and soy). [6.8]
If you want to be extra careful though, then I would leave pots—usually subject to longer cooking times with acidic sauces and whatnot—for the option recommended down below.
Take-aways:
Buy a very high-quality brand (e.g., All-Clad)
Get 18/8 or 18/10 stainless steel (often called “300-series stainless steel”)
Pre-leach it by boiling 1 cup of vinegar in water several times
For instance, 3 cycles of 3 hours each
Avoid cooking acidic foods/sauces (e.g., tomato sauce) in them if you can.
Don’t become paranoid. Stainless steel = good!
Glass Cookware
Finally, some great news.
Pyroceram-glass cookware is, in my opinion, the king of the hill.
Brands like Corningware Visions/LeClair used to sell these for a while, and you can still buy them on eBay and Amazon depending on where you live. It is currently sold by Corelle Brands.
They use a proprietary glass blend called Pyroceram, which is extremely heat and thermal-shock resistant (up to 850°C, or 1,560+°F).
Plus, their special glass is, as far as I can tell, the safest material out there, and leeches have basically no toxic chemicals at all, which is probably why Dr. Raymond Peat was a fan of their range of products.
(This sounds like an ad. It's not. They're not sponsoring any of this.)
In this sense, they represent the best choice on the list, particularly when it comes to cooking things slowly—be it acidic sauces, soups, stews, etc.—where the effects of hardware toxicity are most pronounced.
I reckon their pots are their best product, though they do offer pans as well. If you're interested in them make sure you don't get the non-stick version.
Note that there are several types of glass you can choose from. Oldschool cookware (the one you might find being resold on eBay) is likely made of borosilicate glass, which is extremely heat-resistant.
According to the NY Times however, some years ago Pyrex stopped making borosilicate glass and switched to tempered glass, which is slightly more fragile, but easier to manufacture and less likely to contain boron (some might see that as a plus; others as a minus). [7.1]
Note:
Glass cookware has somewhat of a bad reputation in the U.S. after some people had it break or even explode on them. This was most likely due to them using the product after it had cracked/broken.
The brand makes it very clear ever since not to cook with their products if they show any serious imperfections (e.g., if you dropped them on the floor or into the sink) and offer a 10-year warranty for them.
Honestly, they should be very resistant to daily stresses. After all, Pyroceram was studied and used by NASA as part of the nose cone material in their rockets. [7.2]
Take-aways:
Get borosilicate glass (most resistant)
Alternatively, get tempered glass (also great)
Care for the cookware properly (see instructions below)
Particularly good for pots/longer cooks (e.g., soups, sauces, etc.)
Glass pans work well too, though using them takes some getting used to
Avoid the non-stick version
Glass cookware care tips:
Don’t purchase glass cookware with flaws like chips or blisters, as they weaken the glass and may cause future breakage.
Discard any item that chips during normal use.
Don’t preheat the oven with the cookware inside of it (seems counterintuitive but those are Pyrex’s guidelines).
Avoid placing hot glassware straight from the oven onto cool surfaces. Place them on a towel instead.
If you’re going to transfer the cookware from the oven to the freezer (for whatever reason), let it come to room temperature first, to be safe.
Take-Aways
Avoid as much as possible
Non-stick cookware
Aluminum cookware
Use with care
Ceramic cookware
Enamel-coated cookware
Iron-cast skillet, well-seasoned with ghee or beef tallow
If you have to use any of the above, prevent excessive leaching by…
Washing them lightly with a soft sponge (never a metallic scrub)
Using a light soap to do so (except for the iron-cast skillet; never use soap on it)
Never scratching or chipping the surface (tip: use wooden utensils on them)
Never overheating the pan/pot
Never cooking acidic things on them, especially for a long time (e.g., tomato sauce)
Use for daily cooking
Pyroceram (Borosilicate glass) cookware (ideal)
Tempered glass cookware (second best)
Particularly good for pots/longer cooks (e.g., soups, sauces, etc.)
Glass pans work well too, though using them takes some getting used to (also, avoid the non-stick version)
Stainless steel cookware (honorable mention)
Buy a very high-quality brand (e.g., All-Clad)
Get 18/8 or 18/10 stainless steel (often called “300-series”)
Pre-leach it by boiling 1 cup of white vinegar in water a few times (e.g., 3 x 3 hours)
Not the best option for pots (as they usually imply longer cooking times)
That is all! I hope this helps you (even if very slightly) in your journey towards maximizing your physiological potential.
References
1. PFAS
https://www.niehs.nih.gov/health/materials/perfluoroalkyl_and_polyfluoroalkyl_substances_508.pdf
https://chemicalwatch.com/189390/global-ban-on-pfoa-enters-into-force-for-most-countries
https://www.epa.gov/chemical-research/human-health-toxicity-assessments-genx-chemicals
https://www.sciencedirect.com/science/article/pii/S0160412019325966?via%3Dihub
https://www.documentcloud.org/documents/5316830-EDCs-Androgenic-Activity-Perfluoroakyl.html
2. Aluminum
3. Ceramic
4. Enamel
5. Cast Iron
https://www.alliedacademies.org/articles/effect-of-cooking-utensil-on-iron-content-of-food.pdf
https://academic.oup.com/metallomics/article/2/11/732/6016378?login=false
6. Stainless Steel
7. Glass cookware
https://www.nytimes.com/wirecutter/blog/tempered-vs-borosilicate-glass/
https://ntrs.nasa.gov/api/citations/20030093547/downloads/20030093547.pdf
Re. chemicals in body products - often the best option is simply to avoid a category of product altogether.
If you have short hair, you can probably cut shampoo. Mouthwash isn't necessary if you're brushing your teeth with a good toothpaste. Switch the body-wash for a simple soap. Wear a hat instead of sunscreen. Depending on climate, how physical your job is, and natural smell - you can probably cut deodorant as long as you're showering daily.
Most of these products didn't exist two generations ago anyway!
The Correlle brands can be found here: https://www.corelle.com/shop/cookware
The Visions sub-brand has the Pyroceram cookware. However, I only see pots or 4-inch deep "pans." There is no sauce pan or equivalent. If someone knows of a 10 to 14 inch diameter and 1 to 2 inch deep sauce pan made with this material I would be very interested.