Is spinach harmful in excess?

Mxsmanic <[email hidden]> wrote in :"]news:[email hidden]:

Quoted message said:

Lately I've developed a taste for spinach, and I've been buying little 180 g tubs of cooked
spinach to eat as small meals (usually with some melted cheese mixed in for flavor). I know that
spinach is supposed to be nutritionally good for you in many ways, but are there any risks to
eating a lot of it (say, two of these little tubs a day, or 360 g of cooked spinach)? What about
iron content or other stuff? Or is this way too small an amount to present any risk?

There's a possible concern about the amount of oxalate you'd be consuming, though unless you or
close relatives have had trouble with kidney stones, it's probably pretty hypothetical.

Mxsmanic <[email hidden]> wrote or quoted:

Quoted message said:

Lately I've developed a taste for spinach, and I've been buying little 180 g tubs of cooked
spinach to eat as small meals (usually with some melted cheese mixed in for flavor).

Tried eating it fresh? Much better - IMHO.
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In article said:

Lately I've developed a taste for spinach, and I've been buying little 180 g tubs of cooked
spinach to eat as small meals (usually with some melted cheese mixed in for flavor). I know that
spinach is supposed to be nutritionally good for you in many ways, but are there any risks to
eating a lot of it (say, two of these little tubs a day, or 360 g of cooked spinach)? What about
iron content or other stuff? Or is this way too small an amount to present any risk?

I think the excess oxalic acid may interfere with calcium absorption, or bind with excess calcium to
promote kidney stone formation, but I may be confusing spinach with the cruciferous vegetables
(broccoli).

High iron levels (iron overload) in males may be associated with a greater incidence of heart
attacks, but reports are hazy. Whether 360g of spinach daily is too much, I don't know, in males but
iron overload is more likely than iron deficiency.

Van

--
Van Bagnol / v a n at wco dot com / c r l at bagnol dot com ...enjoys - Theatre / Windsurfing /
Skydiving / Mountain Biking ...feels - "Parang lumalakad ako sa loob ng paniginip" ...thinks - "An
Error is Not a Mistake ... Unless You Refuse to Correct It"

Tim Tyler said:

Tried eating it fresh? Much better - IMHO.

I think I have in the past, but it didn't have much taste.

These little tubs have the spinach pureed and cooked. I think there is something else added for
flavor, but I don't remember what (not in any large amount, though--it's mostly just pure spinach).

I do like spinach and goat cheese mixed together (as in Greek pastries, some types of quiche, etc.).

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In article <[email hidden]>, Van Bagnol

Quoted message said:

High iron levels (iron overload) in males may be associated with a greater incidence of heart
attacks, but reports are hazy. Whether 360g of spinach daily is too much, I don't know, in males
but iron overload is more likely than iron deficiency.

Er, that should have read, "Whether 360g of spinach daily is too much, I don't know; but in males,
iron overload is more common than iron deficiency." HOWEVER, I misread the source of that
information, so I can't construe _anything_ about the prevalence of iron overload.

By the way, RDA for iron is 10mg daily (for males - 15 mg for females of childbearing age), and a
half cup of cooked spinach has about 3.2 mg of iron, so says the charts.

Van

--
Van Bagnol / v a n at wco dot com / c r l at bagnol dot com ...enjoys - Theatre / Windsurfing /
Skydiving / Mountain Biking ...feels - "Parang lumalakad ako sa loob ng paniginip" ...thinks - "An
Error is Not a Mistake ... Unless You Refuse to Correct It"

Van Bagnol <[email hidden]> wrote or quoted:

Quoted message said:

Van Bagnol <[email hidden]> wrote:

Quoted message said:

Quoted message said:

High iron levels (iron overload) in males may be associated with a greater incidence of heart
attacks, but reports are hazy. Whether 360g of spinach daily is too much, I don't know, in males
but iron overload is more likely than iron deficiency.

Er, that should have read, "Whether 360g of spinach daily is too much, I don't know; but in males,
iron overload is more common than iron deficiency." HOWEVER, I misread the source of that
information, so I can't construe _anything_ about the prevalence of iron overload.

By the way, RDA for iron is 10mg daily (for males - 15 mg for females of childbearing age), and a
half cup of cooked spinach has about 3.2 mg of iron, so says the charts.

The iron in spincah is bound up with the oxalate - and is consequently not available:

``Although spinach contains a lot of iron, it also contains oxalic acid which binds to the iron
making it unavailable for absorption. Spinach is still a good source of other nutrients, however.''

- braindance.comvegan.htmOpen ↗

Some think that eating spinach will actually help *reduce* your iron levels - since phenolic
compounds present in it will inhibit iron absorption from a composite meal.
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In article said:

Van Bagnol <[email hidden]> wrote or quoted:

Quoted message said:

By the way, RDA for iron is 10mg daily (for males - 15 mg for females of childbearing age), and
a half cup of cooked spinach has about 3.2 mg of iron, so says the charts.

The iron in spincah is bound up with the oxalate - and is consequently not available:

``Although spinach contains a lot of iron, it also contains oxalic acid which binds to the iron
making it unavailable for absorption. Spinach is still a good source of other nutrients,
however.''

- braindance.comvegan.htmOpen ↗

Some think that eating spinach will actually help *reduce* your iron levels - since phenolic
compounds present in it will inhibit iron absorption from a composite meal.

Hmm, that's strange. Another source reports that oxalic acid (and Vitamin C) helped _increase_ it:

Reddy NS, Malewar VG. Bio-availability of iron from spinach (Spanicia oleracea) cultivated in soil
fortified with graded levels of iron. Plant Foods Hum Nutr. 1992 Oct;42(4):313-8.

"In vitro availability of iron along with ascorbic acid, oxalic acid and phosphorus contents of two
varieties of spinach (Pusa Jyoti and Allgreen) cultivated in soil with different levels of added
iron was determined. Addition of graded levels of iron to soil markedly increased the total iron and
phosphorus contents and significantly decreased the bio-availability of iron, ascorbic acid and
oxalic acid contents of spinach. Ascorbic acid and oxalic acid contents markedly exerted a positive
influence while phosphorus exerted a negative influence on the bio-availability of iron."

<ncbi.nlm.nih.govquery.fcgiOpen ↗
list_uids=1438075&dopt=Abstract>

On the other hand, yet another seems to associate reduced oxalic acid content and increased Fe
availability:

Yadav SK, Sehgal S. Effect of domestic processing and cooking methods on total, hcl extractable iron
and in vitro availability of iron in spinach and amaranth leaves. Nutr Health. 2002;16(2):113-20.

"Drying and storage had no significant effect on total iron content, HCl-extractability and
availability (in vitro), while blanching and cooking resulted in significant improvement of iron
availability, and a significant reduction in oxalic acid content, while only blanching significantly
reduced phytic acid and polyphenol contents. Thus cooking and blanching are good ways to improve
HCl-extractability and in vitro availability of iron."

<ncbi.nlm.nih.govquery.fcgiOpen ↗
list_uids=12102364&dopt=Abstract>

Van

--
Van Bagnol / v a n at wco dot com / c r l at bagnol dot com ...enjoys - Theatre / Windsurfing /
Skydiving / Mountain Biking ...feels - "Parang lumalakad ako sa loob ng paniginip" ...thinks - "An
Error is Not a Mistake ... Unless You Refuse to Correct It"

In article said:

The iron in spincah is bound up with the oxalate - and is consequently not available:

``Although spinach contains a lot of iron, it also contains oxalic acid which binds to the iron
making it unavailable for absorption. Spinach is still a good source of other nutrients,
however.''

- braindance.comvegan.htmOpen ↗

Some think that eating spinach will actually help *reduce* your iron levels - since phenolic
compounds present in it will inhibit iron absorption from a composite meal.

Funny how I find the right article _after_ I've already hit the Send button. Anyway, here it is:

Van Campen DR, Welch RM. Availability to rats of iron from spinach: Effects of oxalic acid. J Nutr.
1980 Aug;110(8):1618-21.

"The availability to rats of iron from two varieties of spinach was determined. Also, the absorption
of Fe was compared between FeCl3 and Fe-oxalate and the effects of adding 0.75% oxalate to the diet
were determined.... The addition of 0.75% oxalic acid to the diet did not depress iron absorption
and, if anything, appeared to enhance iron utilization by rats."

<ncbi.nlm.nih.govquery.fcgiOpen ↗
list_uids=7400851&dopt=Abstract>

Granted, the study _is_ 20 years old, but I've yet to find something more recent that clearly
contradicts it. Other articles in the search discussed phytophenols and iron but their abstracts did
not give much meaningful detail, and apparently the above study suggested a net iron level increase,
rather than reduction, _despite_ whatever phytophenols were present.

Now, _calcium_, on the other hand,...

Van

--
Van Bagnol / v a n at wco dot com / c r l at bagnol dot com ...enjoys - Theatre / Windsurfing /
Skydiving / Mountain Biking ...feels - "Parang lumalakad ako sa loob ng paniginip" ...thinks - "An
Error is Not a Mistake ... Unless You Refuse to Correct It"

Van Bagnol said:

Hmm, that's strange. Another source reports that oxalic acid (and Vitamin C) helped _increase_ it:

I get the impression that there isn't much consensus with respect to the nutritional value
of spinach.

--
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Van Bagnol <[email hidden]> wrote or quoted:

Quoted message said:

In article <[email hidden]>, Tim Tyler <[email hidden]> wrote:

Quoted message said:

Quoted message said:

The iron in spincah is bound up with the oxalate - and is consequently not available:

``Although spinach contains a lot of iron, it also contains oxalic acid which binds to the iron
making it unavailable for absorption. Spinach is still a good source of other nutrients,
however.''

- braindance.comvegan.htmOpen ↗

Some think that eating spinach will actually help *reduce* your iron levels - since phenolic
compounds present in it will inhibit iron absorption from a composite meal.

Funny how I find the right article _after_ I've already hit the Send button. Anyway, here it is:

Van Campen DR, Welch RM. Availability to rats of iron from spinach: Effects of oxalic acid. J
Nutr. 1980 Aug;110(8):1618-21.

<ncbi.nlm.nih.govquery.fcgiOpen ↗
list_uids=7400851&dopt=Abstract>

Also:

``Relationship of components in wheat bran and spinach to iron bioavailability in the anemic rat.''

[...] The addition of 2.10% oxalic acid, the amount in the spinach diet, caused the highest
increase in RBV to 164%. Combining these dietary components, plus lignin (0.67%) and pectin
(0.63%), in various combinations, resulted in RBVs equivalent or significantly higher than 100%.
The bioavailability of iron in plant foods appears to be dependent on how this nutrient is
presented to the mucosa. Cellulose, phytate or oxalate added to a purified diet containing ferrous
iron significantly enhanced the bioavailability of this element. [...]''

- calorierestriction.orgpmidOpen ↗

Together, quite a bit of evidence suggesting the conventional wisdom about iron and oxalate from
spinach is wrong.
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Eric Bohlman said:

There's a possible concern about the amount of oxalate you'd be consuming, though unless you or
close relatives have had trouble with kidney stones, it's probably pretty hypothetical.

I'm not aware of anyone else in my family ever having a stone, but I managed to give myself one by
eating excessive spinach.

Granted, I was eating a lot. I was eating most of a bunch of fresh spinach every day. After several
months (at least six), I passed a small stone. Scared the heck out of me. Fortunately, it didn't
hurt much. I stopped eating spinach after that. Never had another stone. I don't remember how long
ago that was, but it was the last time I was thin -- maybe 15 years ago.

(I lost 40 pounds this year -- low-carb worked for me. However, unlike Atkins, my diet is not
high-protein or high-fat.)

In article said:

Van Bagnol said:

Hmm, that's strange. Another source reports that oxalic acid (and Vitamin C) helped
_increase_ it:

I get the impression that there isn't much consensus with respect to the nutritional value of
spinach.

I don't know if I would say that. Spinach (and dark leafy greens in general) is generally considered
good, but it seems there are some who don't think it's _that_ good. Nevertheless, even the vegan
website that Tim Tyler cited mentioned the following:

"Although spinach contains a lot of iron, it also contains oxalic acid which binds to the iron
making it unavailable for absorption. Spinach is still a good source of other nutrients, however."

What I had been contending was the assertion that spinach was a questionable source of iron because
of its oxalate content. The Medline articles I found seem to suggest that oxalate did not inhibit
iron absorption.

Van

--
Van Bagnol / v a n at wco dot com / c r l at bagnol dot com ...enjoys - Theatre / Windsurfing /
Skydiving / Mountain Biking ...feels - "Parang lumalakad ako sa loob ng paniginip" ...thinks - "An
Error is Not a Mistake ... Unless You Refuse to Correct It"

Van Bagnol said:

What I had been contending was the assertion that spinach was a questionable source of iron
because of its oxalate content. The Medline articles I found seem to suggest that oxalate did not
inhibit iron absorption.

I'm confused. The oxalate binds to the iron, and to the calcium, or is it the calcium that binds to
the iron, or is it the vitamin C that inhibits it all, or what?

In other words, searching around for sources of information on this, I can't seem to ever find the
same conclusion in more than one source. Nobody seems to know how much iron, calcium, oxalate, or
vitamin C (or anything else) gets absorbed from spinach, or whether any of it is good or bad.

In any case, I finished off my last two tubs of pureed spinach, and I haven't bought any more.

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"Mxsmanic" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Van Bagnol said:

What I had been contending was the assertion that spinach was a questionable source of iron
because of its oxalate content. The Medline articles I found seem to suggest that oxalate did
not inhibit iron absorption.

I'm confused. The oxalate binds to the iron, and to the calcium, or is it the calcium that binds
to the iron, or is it the vitamin C that inhibits it all, or what?

In other words, searching around for sources of information on this, I can't seem to ever find the
same conclusion in more than one source. Nobody seems to know how much iron, calcium, oxalate, or
vitamin C (or anything else) gets absorbed from spinach, or whether any of it is good or bad.

In any case, I finished off my last two tubs of pureed spinach, and I haven't bought any more.

pureed spinach??? sounds like a food for a one year old.

I eat spinach for vitamin K, lutien, and other carotenoids. The vitamin C would be absorbed

Quoted message said:

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Once upon a time, our fellow William A. Noyes rambled on about "Re: Is spinach harmful in excess?."
Our champion De-Medicalizing in sci.med.nutrition retorts, thusly ...

NEWSFLASH!

Everything in excess is harmful.

Just thought that you might want to know. 🙂

William A. Noyes said:

pureed spinach??? sounds like a food for a one year old.

It seems to be intended for the general public. It's quite tasty.

Quoted message said:

I eat spinach for vitamin K, lutien, and other carotenoids. The vitamin C would be absorbed

How often do you eat it?

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Yes, I read that Oxelic acid harms the bones.
"William A. Noyes" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

"Mxsmanic" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Van Bagnol said:

What I had been contending was the assertion that spinach was a questionable source of iron
because of its oxalate content. The

Medline

Quoted message said:

Quoted message said:

Quoted message said:

articles I found seem to suggest that oxalate did not inhibit iron absorption.

I'm confused. The oxalate binds to the iron, and to the calcium, or is it the calcium that binds
to the iron, or is it the vitamin C that inhibits it all, or what?

In other words, searching around for sources of information on this, I can't seem to ever find
the same conclusion in more than one source. Nobody seems to know how much iron, calcium,
oxalate, or vitamin C (or anything else) gets absorbed from spinach, or whether any of it is
good or bad.

In any case, I finished off my last two tubs of pureed spinach, and I haven't bought any more.

pureed spinach??? sounds like a food for a one year old.

I eat spinach for vitamin K, lutien, and other carotenoids. The vitamin C would be absorbed

Quoted message said:

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directly.

Mxsmanic" >> How often do you eat it?

I try for a serving a day of cooked greens not counting raw greens like lettuce.

William A. Noyes said:

I try for a serving a day of cooked greens not counting raw greens like lettuce.

But what about spinach specifically? Isn't that supposed to be the dangerous one because of
the oxalates?

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