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mugaliens
2010-Jun-18, 02:53 PM
We're all aware of the concern about the link between aluminum pots and pans and alzheimers. I've heard that when it comes to aluminum pots and pans, this is hogwash, as the Aluminum oxide (Al2O3) coating which forms on the surface of any aluminum exposed to air is very strongly bound and prevents any leaching of the aluminum into whatever one is cooking. I asked a chemist friend of mine who said tomatos and citric juices are nowhere near strong enough to defeat the bonds and allow aluminum to enter the food.

I then though, "What if, in the process of stirring the spaghetti sauce, one used a sharp-edged stainless steel spoon which scraped a thin line from the outer layer of aluminum oxide, thereby exposing the underlying aluminum directly to the spaghetti sauce? What's the affinity between aluminum and the acids in spaghetti sauce?"

Antice
2010-Jun-18, 04:10 PM
We're all aware of the concern about the link between aluminum pots and pans and alzheimers. I've heard that when it comes to aluminum pots and pans, this is hogwash, as the Aluminum oxide (Al2O3) coating which forms on the surface of any aluminum exposed to air is very strongly bound and prevents any leaching of the aluminum into whatever one is cooking. I asked a chemist friend of mine who said tomatos and citric juices are nowhere near strong enough to defeat the bonds and allow aluminum to enter the food.

I then though, "What if, in the process of stirring the spaghetti sauce, one used a sharp-edged stainless steel spoon which scraped a thin line from the outer layer of aluminum oxide, thereby exposing the underlying aluminum directly to the spaghetti sauce? What's the affinity between aluminum and the acids in spaghetti sauce?"

pretty low is my guess. it would lead to the now freshly exposed aluminium to oxidize rapidly. the acids in tomato is afaik not strong enough to disolve the oxide layer. but i could easily be wrong on that.
Potatoes otoh I do know has an affinity for disolving aluminium. it is readily evident if you boil potatoes in an aluminium pot. the discoloration and pitting of the surface makes it rather self evident even after a fairly short while doing this. so definately not a great idea to use aluminium pots for that.

Gillianren
2010-Jun-18, 04:27 PM
The idea that there's a link between aluminum and Alzheimer's is at best dodgy. There are other reasons to avoid storing acidic foods in aluminum containers, though cooking in them is usually fast enough so that it's not a problem. But Alzheimer's is not that reason.

Strange
2010-Jun-18, 04:33 PM
I'm with Antice, the exposed Al would be rapidly covered by a protective layer so almost none would be dissolved. Look at how slowly Al dissolves even in strong acids.

On the other hand, the idea that there is any connection between Al and Alzheimers is pretty much discredited AFAIK. But, as usual, this side of the story never gets as much publicity.

Finally, the body is pretty much unable to absorb aluminum even if you do ingest it.

Swift
2010-Jun-18, 04:41 PM
Regarding aluminum and Alzheimer's, here (http://alzheimers.org.uk/site/scripts/documents_info.php?categoryID=200137&documentID=99&pageNumber=1) is some information from the Alzheimer's Society of the UK

A number of environmental factors have been put forward as possible contributory causes of Alzheimer's disease in some people. Among these is aluminium. There is circumstantial evidence linking this metal with Alzheimer's disease, but no causal relationship has yet been proved. As evidence for other causes continues to grow, a possible link with aluminium seems increasingly unlikely. This factsheet looks at the circumstantial evidence and current medical and scientific views.

And here (http://www.webmd.com/alzheimers/guide/controversial-claims-risk-factors) is a bit from WebMD

One of the most publicized and controversial theories concerns aluminum, which became a suspect in Alzheimer's disease when researchers found traces of this metal in the brains of patients with Alzheimer's disease. Many studies since then have either not been able to confirm this finding or have had questionable results.

Aluminum does turn up in higher amounts than normal in some autopsy studies of Alzheimer's patients, but not in all. Further doubt about the importance of aluminum stems from the possibility that the aluminum found in some studies did not all come from the brain tissues being studied. Instead, some could have come from the special substances used in the laboratory to study brain tissue.

grant hutchison
2010-Jun-18, 05:02 PM
Finally, the body is pretty much unable to absorb aluminum even if you do ingest it.About 1% is absorbed, but it varies according to the presence or absence of substances that bind aluminium. What is absorbed is promptly excreted by the kidneys.
There are significant quantities of aluminium in tomatoes, onions, garlic and many spices, so you probably ingest more aluminium from your spaghetti sauce than you do from the cookware. There are also notably high levels of aluminium in tea and coffee, both of which have an epidemiological link to a reduced incidence of Alzheimer's.

Grant Hutchison

mugaliens
2010-Jun-18, 08:37 PM
About 1% is absorbed, but it varies according to the presence or absence of substances that bind aluminium. What is absorbed is promptly excreted by the kidneys.
There are significant quantities of aluminium in tomatoes, onions, garlic and many spices, so you probably ingest more aluminium from your spaghetti sauce than you do from the cookware. There are also notably high levels of aluminium in tea and coffee, both of which have an epidemiological link to a reduced incidence of Alzheimer's.

Grant Hutchison

In what chemical form? Chlorine is a killer, but both potassium chloride and sodium chloride are required for normal operation...

Good info on the prevalience of aluminum in other forms, though.

grant hutchison
2010-Jun-18, 10:00 PM
In what chemical form? Chlorine is a killer, but both potassium chloride and sodium chloride are required for normal operation...Dietary aluminium from natural sources comes in the same form as the stuff dissolved out of your pots and pans by foodstuffs: aluminium ions from the salts of organic acids, and insoluble aluminium phosphate. You absorb the former and excrete the latter.

Moderate concentrations of chloride, potassium and sodium ions are required for normal physiological function; likewise low concentrations of hydrogen ion. But the very high concentrations of hydrogen and chloride ions [plus hypochlorite] generated by the solution of chlorine gas disrupt normal physiology. So it's just a matter of degree. In contrast, aluminium ions have no known physiological function, so they are a pure hit against normal physiology: they compete for metabolic pathways with useful ions like iron and calcium.

Grant Hutchison

Ivan Viehoff
2010-Jun-19, 07:21 PM
In my youth I dissolved holes in aluminium foil by putting it in contact with highly acidic foodstuffs such as cooked blackcurrants and rhubarb.

But it is worth remembering that "muckite", ie the inorganic component of garden soil, contains a lot of aluminium, aluminium being of exceedingly high abundance in the general rocks and stuff around us. In particular it is of high abundance in common clay minerals, which are typically aluminosilicates, that form a substantial component of soils. Such substances are also used as inorganic fillers in stuff like toothpaste, tablets, etc. So we are consuming significant amounts of aluminium to the extent that we breathe in dust and eat trace amounts of muckite off our vegetables, an important part of our mineral intake.

The main concern I have with dissolved aluminium pan or foil is that when it happens the resultant food is often horribly tainted in taste, and it may react horribly with certain other components of the dish to curdle. Also reminds me of the time my mother ruined a summerpudding by using a copper-bottomed pan as a weight to press it.

I cook mainly in enamel-coated pans.

Jeff Root
2010-Jun-19, 08:38 PM
I have an old, cheap, Mirro aluminum cooking pot that I've used
for decades. It seems to me that it was less than one decade ago
that I noticed the dark gray stuff that comes off when I clean it.
I have been intending to ask about it, and the possible connection
with Alzheimer's, for a long time. I was also wondering about the
aluminum oxide coating, same as mugs.

I first noticed the dark gray stuff when I cleaned the pot with a
green 3M Scotch-Brite pad. I didn't know at first whether it came
from the pad or the aluminum, but I quickly found that it comes
from the aluminum. Ever since I have rubbed the pan dry with
a paper towel until the gray stuff pretty much stops coming off.

Also, the edge of the old desk I'm sitting at, made in the 1940's,
is a silver-colored metal. Since it has some pitting and scratches
in it, I thought it might be aluminum. The entire rest of the desk
is steel, so I can't tell for sure whether a magnet is attracted to
the narrow edging. When I wipe this silvery edging with a white
paper towel, gray stuff comes off, similar to the aluminum pot.

-- Jeff, in Minneapolis

JonClarke
2010-Jun-19, 11:13 PM
I've never noticed any funny tasts will aluminium cooking pots.

BigDon
2010-Jun-21, 05:51 PM
pretty low is my guess. it would lead to the now freshly exposed aluminium to oxidize rapidly. the acids in tomato is afaik not strong enough to disolve the oxide layer. but i could easily be wrong on that.
Potatoes otoh I do know has an affinity for disolving aluminium. it is readily evident if you boil potatoes in an aluminium pot. the discoloration and pitting of the surface makes it rather self evident even after a fairly short while doing this. so definately not a great idea to use aluminium pots for that.

Aluminum is more reactive to alkaline substances than acidic ones. That's why you can't use oven cleaner on aluminum surfaces, (without damaging them.)

Jeff Root
2010-Jun-27, 03:03 AM
I would expect that most dishwashing detergents are alkaline.
So my pot forms the gray stuff because of the alkaline detergent?

-- Jeff, in Minneapolis

Antice
2010-Jun-27, 07:45 AM
I would expect that most dishwashing detergents are alkaline.
So my pot forms the gray stuff because of the alkaline detergent?

-- Jeff, in Minneapolis

Is it alcaline? hmm.. that is something that i have never thought about. I always asumed it was acidic because most other soap types are. and most soap contain fair amounts of mineral salts as well. Acids are generally better solvents than alcaline substances. especially in conjunction with salts. the acids disolves fat and protein, and the salts help keep them suspended in the washwater. Alcaline water is generally a problem for dishwashers. hence why we need to add iodine enriched salt in areas where the water is very alcaline. Failing to do so will result in everything becoming covered in a thin layer of limestone deposits I've found that standard iodine enriched salt for cooking is a cheaper and adequate replacement for the special stuff they flog at the apliances stores where i live. The cost balance may be very different elsewhere. it's just that in general we do not have alcaline water in Norway. only a few places have these issues at all. Hence the cost of the propper stuff is high with the market being so small and all.

mugaliens
2010-Jun-27, 06:26 PM
Is it alcaline? hmm.. that is something that i have never thought about. I always asumed it was acidic because most other soap types are. and most soap contain fair amounts of mineral salts as well.

Traditional soaps are anionic surfactants, and they're alkaline, ranging in pH from about 8 to 9. They work because soap molecules have both a water-soluable hydrophilic end and and a grease-dissolving hydrophobic end. Modern soaps range from 5 to 8 in pH, with higher pH values being better for greasy/oily soils.

It's a misnomer that lower pH soaps are "milder." The action of a soap is based less on its pH than on the results of the saponification process.

Gillianren
2010-Jun-27, 07:29 PM
I always asumed it was acidic because most other soap types are.

Where did you get that? Most early soaps were formed with lye.

Antice
2010-Jun-27, 08:08 PM
Where did you get that? Most early soaps were formed with lye.

Probably from the same place a lot of other misconceptions arise. It's what happens when you do not actually do any proper research about an object. Soap is made by chemically altering fat. and they contain a lot of fat related chemicals. fat is acidic after all. The soap we made in chemistry class when i was 14 was fairly acidic. we probably didn't do it entirely right tho. btw. that chemistry class was like 18 years ago. haven't done much chemistry since tbh. Most of the stuff i have dealt with later in life has involved semiconductors, sweat and grease.

jj_0001
2010-Jul-02, 01:07 AM
Probably from the same place a lot of other misconceptions arise. It's what happens when you do not actually do any proper research about an object. Soap is made by chemically altering fat. and they contain a lot of fat related chemicals. fat is acidic after all. The soap we made in chemistry class when i was 14 was fairly acidic. we probably didn't do it entirely right tho. btw. that chemistry class was like 18 years ago. haven't done much chemistry since tbh. Most of the stuff i have dealt with later in life has involved semiconductors, sweat and grease.

A soap is an organic acid, usually a fatty acid, coupled to a base, to make it highly polar. Not sure where this fits in to your discussion, really, but that's what a soap is.

http://en.wikipedia.org/wiki/Soap

ETA: One should not trust memory, in fact it's a hydrophobic end and a hydrophilic end that makes a soap. This doesn't have to be polar. But it often is, potassium and sodium being, well, kinda on one end of the electronegativity spectrum.

mike alexander
2010-Jul-05, 03:31 PM
A classic soap is produced by the deesterification of fats (fatty acid triglycerides) with a base (e.g. sodium hydroxide, or potassium hydroxide for soft soap).
The free fatty acids (long-chain carboxylic acids) exist as their sodium salts and are somewhat soluble in water (solubility increases with temperature; that's why warm water makes more lather).
The fatty acid salts are mildly basic. If you add an acid to a soap solution you will form the free fatty acid, which will precipitate (since it is much less soluble in water). Soap scum is mainly the insoluble calcium and magnesium salts of fatty acids. For that matter, 'lithium grease' is mostly the lithium salt of stearic acid, essentially lithium soap scum.

Detergents are synthetic or semi synthetic, usually classed as cationic (ammonium-based) or anionic (sulfates and sulfonates); there are also nonionic detergents.
Dishwasher detergent is a mixture of a synthetic detergent and either sodium carbonate or sodium phosphate; the latter two provide the higher pH that assists scum and fat removal.
The higher pH of these materials can contribute to long-term pitting of aluminum cookware. Note that the oxide film that forms is the same film that forms on an aluminized telescope mirror. It's tough, but you probably wouldn't wash your primary in the dishwasher.

mugaliens
2010-Jul-06, 07:56 AM
Note that the oxide film that forms is the same film that forms on an aluminized telescope mirror. It's tough, but you probably wouldn't wash your primary in the dishwasher.

While at the star stare recently, I was surprised to learn there are two camps to cleaning lenses and mirrors. The first is "Never!" and the second uses progressively more aggressive methods to rid the mirror/optics of dust and other debris. One guy claimed not to have cleaned his mirror with anything other than a can of air in more than seven years since he built it.

It showed.

sabianq
2010-Jul-06, 03:31 PM
We're all aware of the concern about the link between aluminum pots and pans and alzheimers.


http://alzheimers.org.uk/site/scripts/documents_info.php?categoryID=200137&documentID=99&pageNumber=1

There is circumstantial evidence linking this metal with Alzheimer's disease, but no causal relationship has yet been proved. As evidence for other causes continues to grow, a possible link with aluminium seems increasingly unlikely.

kind of like the link between flouride and mental impairment or aspartame and tumors or cell phones and brain cancer or ...???

sabianq
2010-Jul-06, 03:43 PM
also dont forget high school chemistry that shows a very strong reaction between aluminum and water..
Aluminum metal rapidly develops a thin layer of aluminum oxide and hydrogen as a byproduct.
Al3+(aq) + 6H2O(l) <-> [Al(H2O)6]3+ (aq)

so scraping your pan with a metal spoon will only release aluminum oxide into the food (assuming there is any water in the food) which is non reactive..




Read more: http://www.lenntech.com/periodic/water/aluminium/aluminum-and-water.htm#ixzz0suulZzYv

Gillianren
2010-Jul-06, 05:19 PM
kind of like the link between flouride and mental impairment or aspartame and tumors or cell phones and brain cancer or ...???

Vaccination and autism. Quite.

neilzero
2013-Jan-04, 01:41 AM
There is big money riding on the safety of aluminum in food, so I tend to be skeptical of claims that alumium has no health problems as alumium acetate, aluminum oxide, cream of tarter or what ever aluminum compound you get when aluminum disolves in sodium hydroxide. It seems to me that human absorbsion would vary widely with the anion, and other health risks besides alsheimers cannot be ruled out. Nobody said how many parts per billion are found in average human tissue. That number and the range in various cultures and locals should not be expensive to determine. No one said which animals are poisoned by megadoses of various aluminum compounds. There is a possiblity that the average human would benefit from a low aluminum intake, especially if only biased and puny studies have been done. Neil

Gillianren
2013-Jan-04, 04:06 AM
You resurrected a two-and-a-half-year-old thread for unfounded skepticism?

Jens
2013-Jan-04, 04:40 AM
neilzero seems to have done it several times this morning. I suspect he may have just enrolled for a degree in necromancy.

Inclusa
2013-Jan-04, 09:26 AM
neilzero seems to have done it several times this morning. I suspect he may have just enrolled for a degree in necromancy.

Such practice can save the urge of opening new threads, though.

Jeff Root
2013-Jan-04, 11:02 AM
I still want to know what that gray stuff is!!! (Post #10)

-- Jeff, in Minneapolis

grant hutchison
2013-Jan-04, 03:25 PM
I still want to know what that gray stuff is!!! (Post #10)It's aluminium oxide powder. You're partially stripping the oxide layer with your cleaning pad. It doesn't take much force - it's easy to get aluminium oxide "scuff marks" on a porcelain sink, for instance, if your pan hits the side of the sink during washing. If the "gray stuff" has only started appearing after long use, your cookware may well have been sold with a protective anodized layer that has been stripped off with repeated cleaning, so now the porous metal surface is exposed.
You shouldn't clean aluminium cookware with anything more abrasive than hot water, soap and a sponge.

Grant Hutchison

Inclusa
2013-Jan-05, 04:36 AM
Should we switch to ceramic pans? I haven't seen ceramic pots yet, though.

danscope
2013-Jan-05, 05:04 AM
Stainless steel.... perhaps with a heavy clad bottom will always be better to cook with . If you have no-stick aluminum
and use silicone and bamboo tools, they should last a long time. There should never be any metal tool in an aluminum pan.
Really.

NEOWatcher
2013-Jan-07, 03:34 PM
Should we switch to ceramic pans? I haven't seen ceramic pots yet, though.
All ceramic or ceramic coated (http://www.always-free-shipping.com/orgreenic-5pc-cookware-set1.html?cmp=googleproducts&kw=orgreenic-5pc-cookware-set1&utm_source=GoogleShop&utm_medium=cse&utm_campaign=orgreenic-5pc-cookware-set1&gclid=CJWEqNfI1rQCFYKK4Aod7zcAVg)?

profloater
2013-Jan-07, 06:00 PM
going back to the OP, someone should add more data about the original link to aluminium which was on slides of cells and it was comprehensively shown that it was an artifact caused by the way the slides were stained. In other words the evidence was completely discredited but this rumour persists. If there is any solid evidence at all that aluminium is a factor in Alzheimers then let someone cite it. Many years have passed and as far as I have read, Aluminium has never been added to a risk list since that very early report. I follow the news on big A because my dad died of it and so did my wife's dad. (And I have no vested interests)

grant hutchison
2013-Jan-07, 07:43 PM
going back to the OP, someone should add more data about the original link to aluminium which was on slides of cells and it was comprehensively shown that it was an artifact caused by the way the slides were stained. In other words the evidence was completely discredited but this rumour persists. If there is any solid evidence at all that aluminium is a factor in Alzheimers then let someone cite it. Many years have passed and as far as I have read, Aluminium has never been added to a risk list since that very early report. I follow the news on big A because my dad died of it and so did my wife's dad. (And I have no vested interests)I didn't actually understand neilzero's little rant (http://cosmoquest.org/forum/showthread.php/105113-Question-about-Aluminum-Oxide-and-Aluminum-Pots-and-Pans?p=2094775#post2094775), which was responsible for the automated e-mail that brought me back to this thread.
But anyone who wants documentation, or who feels that aluminium toxicity hasn't been adequately investigated, should trawl through Krewski et al. (2009) Human health risk assessment for aluminium, aluminium oxide, and aluminium hydroxide (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2782734/). It provides more than 1500 references!

Grant Hutchison

profloater
2013-Jan-08, 05:45 PM
I didn't actually understand neilzero's little rant (http://cosmoquest.org/forum/showthread.php/105113-Question-about-Aluminum-Oxide-and-Aluminum-Pots-and-Pans?p=2094775#post2094775), which was responsible for the automated e-mail that brought me back to this thread.
But anyone who wants documentation, or who feels that aluminium toxicity hasn't been adequately investigated, should trawl through Krewski et al. (2009) Human health risk assessment for aluminium, aluminium oxide, and aluminium hydroxide (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2782734/). It provides more than 1500 references!

Grant Hutchison
Very grateful for this long reference which I did trawl through and the following also long quote is about alzheimers. Please read the last paragraph which gives reasons to dissociate aluminium from that disease:

Dementia: In a study of 20 AD subjects aged 65 to 76 ...

(Mod note: Please, no long quotes from a copyrighted paper. A snip is good with a link to the original article.
Krewski et al. (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2782734/))

Pennine
2013-Jan-12, 10:26 PM
In England some 20 years ago or more an Aluminium compound was released into a local water supply by accident from the water supplier , there were some quick deaths and drawn out problems.
Please get rid of any uncoated Aluminium pans or Pressure cookers now !
Certain cooked items leach the Aluminium out of the cooking pots , rubarb, beans etc.

profloater
2013-Jan-13, 03:10 PM
In England some 20 years ago or more an Aluminium compound was released into a local water supply by accident from the water supplier , there were some quick deaths and drawn out problems.
Please get rid of any uncoated Aluminium pans or Pressure cookers now !
Certain cooked items leach the Aluminium out of the cooking pots , rubarb, beans etc.
That incident (Camelford) certainly turned some hair green but I think you will find there were no quick deaths, it is reported in the long paper quoted above. The water there had a huge load of Aluminium sulphate but in any case cannot be compared to cooking with aluminium. By far the biggest aluminium uptake is in workers in the industry and they show no signs of having elevated incidence of dementia. This kind of advice is pure unscientific panic. I would agree that cooking acids in aluminium is not a good idea but only as a general rule, Keep things in proportion. The long and very comprehensive study cited above states that it is very unlikely that aluminium in the brain increases the risk of Altzeimers. (I repeat I have no vested interest, it's just a shame that rumours persist despite the evidence.

Squink
2013-Jan-13, 04:43 PM
Aluminum's oxide layer isn't all that bulletproof:
Modelling acidic corrosion of aluminium foil in contact with foods (http://onlinelibrary.wiley.com/doi/10.1002/pts.2770030404/abstract)
Lasagna, for instance, is notorious for eating holes in a covering of aluminum foil over the course of a few days (http://www.realsimple.com/food-recipes/tools-products/aluminum-foil-dos-donts-10000001154398/index.html). The white stuff that replaces the foil isn't oxides, it's acid salts.

Inclusa
2013-Jan-16, 03:43 AM
All ceramic or ceramic coated?

These are all ceramichttp://www.ceramcor.com/; I don't know if the ceramic exterior provide any advantages, though.

kzb
2013-Jan-16, 12:46 PM
There were definitely some studies which measured the aluminium concentrations of acidic foodstuffs cooked in aluminium pans, and the aluminium was increased. So that I think is established. As to whether this has any connection with Alzheimers, well it looks doubtful.

You can still buy stomach antiacid tablets which consist of aluminium salts. The amount of Al in one dose of these probably exceeds the amount you take in from aluminium cookware in a full year. They're still allowed to sell them over the counter.

Tea is high in Al, as noted by Grant Hutchinson. It is also high in fluoride; in other words you have Al complexed by F. This is a very tightly bound complex, and I think it renders both constituents much less harmful than they are on their own.

Personally, and just to be on the safe side, I wouldn't take these Al-based medications nor cook acid food in non-coated aluminium pans. But I drink a lot of tea.

profloater
2013-Jan-16, 01:02 PM
yes there are many ways to take in Al, deodorants are al compounds, usually, and it can be in the drinking water too. Since there are no known deficiency effects it is reasonable I guess to avoid extra Al but there are many other risks in everyday life.