The Spinach Inquisition

[Mojo]

A recent thread about organic food reminded me of something I tried to investigate a couple of years ago. It came from the Ask Emma (http://www.guardian.co.uk/weekend/story/0,,1049806,00.html) column in the Guardian. In a piece justifying the use of food supplements she included the claim: ... in 1948, for example, 100g of spinach had 158mg of iron; now, it has 1mg. The iron content of spinach having fallen by 99.4% in a little over 50 years seemed a rather extreme claim, so I tried to find a reliable source for it. All I could find was various sites repeating the same claim, some hinting that the information came from a US government Department of Agriculture report, but not giving any sort of reference.

Does anyone know anything about where this claim originated? Does anyone have a reliable source for it? Alternatively, does anyone have anything rebutting it?

[geni]

Way back in 1870 Dr. E. von Wolf misplaced a decimal point in his which publication led to an iron-content figure that was ten times too high. This had been corrected by 1937.

T.J. Hamblin published some stuff (along with covering some other mistuderstandings about the iron content of food in the British Medical Journal, December 1981.

http://en.wikipedia.org/wiki/Spinach#Nutrition

[Badger]

I wasn't expecting that.

[Mojo]

Way back in 1870 Dr. E. von Wolf misplaced a decimal point in his which publication led to an iron-content figure that was ten times too high. This had been corrected by 1937. Thanks for that. It certainly indicates that the 158mg/100g claim is wrong, but it's not a big enough error to have given a figure one hundred times too high. It also doesn't explain where the "1948" claim originates. For example this page (http://www.viscent.com/page/191) specifically claims that the figure came from a 1948 "USDA tests". Of course, it could be that once a spurious claim like this is put up somewhere, it will just keep on being repeated by people whose agenda it suits.

Incidentally, while Googling for that, I found this (http://www.bisley-with-lypiatt.gov.uk/pc08.htm): Have you ever wondered why it is often recommended you take vitamin supplements?

'The quality of non-organic fruit and veg is depleted by the wide use of pesticide and cheap fertilizers. Soil no longer contains the minerals for plants to take up: in 1948 for example 100g of spinach had 158mg of iron; now it has 1mg... most of the vitamins have been lost from our food.'

Is this a quote from raving lunatic? No, it is from this weekend (27.09.03) Guardian's Well-being column.
:hb:

[fuelair]

Friendly suggestion: Dogpile (can't url yet), Spinach iron Fetch : Wickipedia,etc (no, they aren't necessarily saying the why that data exists except to note one of a number of older nutritional information errors due to miscalculations, poor technique and plain old typographical errors) BUT is the iron content of exactly duplicated quantities of organicly grown and normally grown spinach - of the same variety - functionally different? If so, we may have a supernatural occurence (or iron is being added in the fertilizer). Since I am not a botanist, I can only state that I assume the plant would only extract the amount of iron it needs for its' functions so if sufficient iron is in the ground "naturally" or by added fertilizer, the iron content should be the same - and should not be any different than it was in 1948.

[Mojo]

I wasn't expecting that.:D

[geoman]

I wasn't expecting that.

Nobody expects...

:rolleyes:

[andyandy]

yeah....someone misplaced the decimal place.....

The myth about spinach and its high iron content may have first been propagated by Dr. E. von Wolf in 1870, because a misplaced decimal point in his publication led to an iron-content figure that was ten times too high. In 1937, German chemists reinvestigated this "miracle vegetable" and corrected the mistake
http://en.wikipedia.org/wiki/Spinach

which is why on popeye he eats spinach to make himself strong...

[Popeye's use of] spinach comes from the publication of a study which, because of a misprint, attributed to spinach ten times its actual iron content. Nevertheless, the popularity of the character helped boost sales of the vegetable and the spinach-growing community of Crystal City, Texas erected a statue of the character in gratitude. There is another Popeye statue in Segar's hometown, Chester, Illinois. Another statue is in Alma, Arkansas, which claims to be "The Spinach Capital of the World", and is home to Allen Canning which markets Popeye-branded canned spinach.
http://en.wikipedia.org/wiki/Popeye

[andyandy]

although that doesn't answer your OP :D

I'd just down put the claim that the "iron content in spinach has fallen by over 99% over the last few decades" as a journalistic mistake....

[Meffy]

Nobody expects...
These days, vampiric birds suck out the iron from spinach plants while reciting Monty Python skits. The worst offender is the well-known cardinal fang.

Didn't think cardinals had fangs? Au contraire. They're right between the brille and the drumstick.

[Mojo]

I'd just down put the claim that the "iron content in spinach has fallen by over 99% over the last few decades" as a journalistic mistake.......or a woo porkie.

[Meffy]

...or a woo porkie.
=o.O= A "woo porkie"...? Sounds like a variant on the Cornish meat pie.

[Mojo]

Mind you, having done a bit more Googling today, I see that Emma seems to be having trouble keeping her stories straight. Having said in the column I linked to above that supplements are necessary because, among other things, spinach doesn't have enough iron in it these days, here (http://www.guardian.co.uk/weekend/story/0,,1738100,00.html) she is giving advice on treatment for a child with a tendency to anaemia. Guess what: To address the anaemia, give her lots of iron-rich foods such as green vegetables (especially broccoli and spinach):rolleyes:

[Hellbound]

=o.O= A "woo porkie"...? Sounds like a variant on the Cornish meat pie.

I dunno, I was thinking along the lines of a brief and hurried sexual interlude with a psychic believer.

But maybe that's just me.

[sciguy]

While googling around for that other thread, I had come across one bit (sorry, I can't remember exactly which site, maybe organic-center.com) that mentioned something that might apply here. Commercially grown vegetables have smaller root systems than organically grown, because the plants don't have to go as "far" to get sufficient amounts of their main nutrients (nitrogen, potassium, phosphorous) due to fertilization. However, this also means that they have less access to trace elements (I think Iron and Zinc were specifically mentioned) which may not be critical to the plant's growth would contribute to the nutrients gained by eating the plant.

It makes sense (which obviously still isn't proof). Minerals like Iron aren't going to come from the air, and isn't likely to come from water (although this could be a source, depending on what the water supply is), so plants have to get it from the ground. It didn't look like they pointed out any correlation between root system size and nutrient content. Would a 50% smaller root system imply 50% fewer minerals? It's also possible that the soil gets depleted of trace elements as it gets reused for crops year after year, which might also contribute to lower iron content compared to earlier crops.

[Pup]

Could this have anything to do with the bioavailability of the iron? As I understand it, non heme-iron from things like spinach isn't as well utilized by the body as iron from beef, for example. If calculations were changed to reflect the amount of iron that can actually be used by the body, vs. the amount that's in the food, it would look as if the iron content had dropped. Haven't googled to see if there's any basis, just a possible avenue to explore.

I still don't know if it would be enough to explain the other factor of ten though that's left after the decimal place error.

[andyandy]

you do realise that emma's only a "natural health therapist" - sounds to me like one of those woo-science titles that people give themselves to disguise the fact that their only qualifications are a C grade GCSE in biology and a certificate from www.youtoocanbeahealththerapist.com ......:D



or maybe i'm just being cynical.....

ps. the link won't work....:)

[andyandy]

lol

10 seconds on google....


Our Courses are recognises by many for example The CMA (Complementary Medical Association) & The Guild of Holistic Therapists. We pride ourselves on offering excellent courses & teachers and your satisfaction is our prime concern. We have built a long standing reputation for excellence and we as a company are here to make sure it continues.

“I have noticed some of your courses are just one day, can I learn all I need to in just one day?”
YES! Our philosophy is to keep classes small and give more attention to each student, thus cutting down on class hours. You will learn the same technique offered by other companies however we pride ourselves on one to one tuition in smaller classes.

ooh....i fancy having a ITEC Level 3 Diploma in Anatomy and Physiology....

A course, covering all the anatomy and physiology of the body. Designed to the highest standard to give the student a basic understanding in a clear manner of the structures, functions and pathology of the human body and how each of the functional systems interacts.


that sounds pretty academic....must be quite a long course....yeah?

We offer this course in 5 intensive days (£700) or alternatively over 4 modules (4 months)

wow....5 days OR 4 months - those 5 days must really pack it in

so what happens then?

You will receive your diploma certificate on the day of training and once you have practiced and feel confident you are able to take the therapy you have learnt out to the general public and charge for it as they are insurable courses.

so there we have it....have £700 and a spare week? You too can be a qualified natural health therapist....who knows - you might even get a job at the guardian :)

http://www.gatewayworkshops.com/

[Mojo]

Could this have anything to do with the bioavailability of the iron? The "1958" claim seems to be to do with the iron content of spinach, not the degree to which it is absorbed in the gut.

[Thing]

Since Ben Goldacre, who writes the Guardian's Bad Science column, isn't allowed to write about her frequent daftness/uselessness/dangerousness perhaps someone else (with more time and web-nous than I) should set up bademma.org or dont-ask-emma.org or whatever to host the articles Ben would have written about her if he was allowed. I'm sure between us we could come up with some reasonable content. Any takers?

[Hawk one]

Slightly related, this reminds me of something I did see on the news a few weeks back (I'll do the research a bit later, OK?)

Apparently, many vegetables have had a certain decline in how much of the good stuff (i.e. vitamins and minerals) they contain per kilogram.

However, it's not nowhere as scary as 99,4% decline, and the reasoning at least -seems- more plausible to me (as a complete layman): Said vegetables are simply growing faster and bigger than they used to do. And that means they get less time to for excample suck up minerals from the soil, and all that jazz.

Like I said, I'll try and check out this later, if anyone's interested to see if this story's got any truth in it.

[Mojo]

However, it's not nowhere as scary as 99,4% decline, and the reasoning at least -seems- more plausible to me (as a complete layman): Said vegetables are simply growing faster and bigger than they used to do. And that means they get less time to for excample suck up minerals from the soil, and all that jazz.This was one of the things being discussed in the thread about organic foor I mentioned in the OP. It was suggested that organic vegetables may have more nutrients because organic farmers choose slower-growing varieties. Of course, this would mean that they aren't higher in nutrients because they're organic, but because they're slower growing.

[neil]

Likely spinach has not lost 99% of it's iron. Even a 90% loss is doubtful. There is a consensus that our food is less nutritious. Generous use of inorganic fertilizer could mean smaller root systems. Failure to rotate crops and leave the ground unplanted each 7th year has likely reduced the trace soil nutrients the plants can use. The variable unspecified amount of iron in commercial fertilizers may mostly be in compounds which most plants can't use. Someone claimed some humans do not retain any iron in the form of iron sulphate. They did not specify ferrous or ferric. Non perscription drugs and nutrients typically are poorly researched and double blind tests are very rare because of the high cost. Perhaps applicable to this discusion, several tons of iron compounds were once sprinkled in the ocean and the result was a large increase in algae = a one celled plant.
I try to eat a wide variety of foods, from a wide variety of sources and brands, and take much smaller than recommended doses of a wide variety of supplements. I avoid caffein, aspertain, alcohol, nicotine and other substances many people abuse. I cut way back on animal fat and eat mostly whole grains rather than refined and processed foods. I drink almost 3 liters of water most days. I rarely need perscription drugs and am reasonably healthy at age 73. Perhaps more important, I rarely get stressed over anything. Neil