Home-Low Oxalate Diet

Home-Low Oxalate Diet

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Home-Low Oxalate Diet

This site is for informational purposes only.
Please consult with a qualified medical
professional before making any dietary changes.

Oxalate is a very simple sort of molecule. It links up with
calcium and crystallizes under some conditions, including when it
encounters damaged tissues. The crystals formed this way can be quite
irritating and painful to tissues where they cause or increase
inflammation. These crystals can be especially painful if they lodge
themselves in places where they get in the way of the movement of
other things through tight places.

These physical issues are easy to understand, but there are still
many secrets being discovered about how oxalate interacts with our
metabolism. Research shows that it tangles with cellular issues like
altering the cell membrane by lipid peroxidation and oxidizing and
interfering with the trafficking of glutathione. In the
mitochondrion it impairs many enzymes that furnish the energy for
cell life. Oxalate changes what happens in the cytosol, the fluid
interior of cells where calcium waves regulate complex chemistry, and
where it can also alter the function of ion channels. Oxalate
changes calcium storage in the endoplasmic reticulum where calcium is
kept available for cell signaling and cell death programs. Oxalate
enters the nucleus of cells, where DNA gives the recipe for making
proteins, but there oxalate modifies transcription in unknown ways
that are only now being studied.

Because it is so reactive, oxalate also interferes with the duties
of many other positively charged ions like magnesium, zinc, copper,
iron, manganese, and more. This may alter the role of these ions in
enzymes and in other complex molecules. Oxalate specifically impairs
iron’s intracellular release, and interferes with the whole class of
biotin-dependent enzymes called carboxylases. These disruptions of
cell chemistry are not what happens when oxalate is bound to calcium,
but are what happens when it ISN’T bound to calcium. Its free state
allows it to cross into the cell as an ion on transporters generally
designed to move sulfate into cells. When someone is low in sulfate,
this may change where oxalate is taken.

Where does oxalate come from?

Oxalate is present in a lot of plants and fruit that we eat. It
is especially high in almost all seeds and nuts, but in some more
than others. Ordinarily, the gut won’t absorb much of the oxalate
from the diet because most of the oxalate will be metabolized by the
flora or just leave the body with the stool. Under other conditions,
such as when there is gut inflammation, a lot of dietary oxalate is
absorbed. The difference can be as great as going from 1-2% of the
dietary oxalate absorbed to as high as 50%.

Over absorption of oxalate will also occur when the tight
junctions between intestinal cells open up and let molecules pass to
the other side going between the cells. This condition, called the
“leaky gut”, may happen during illness, or when cells in
the gut die, leaving gaps, and may bring with it allergies to foods.
This condition is similar to when the bladder has open junctions
called the “leaky bladder”, or when the blood brain barrier
is compromised. The colon may also absorb too much oxalate when
small bowel function is compromised by surgery, by poor pancreatic
function, and/or by fat maldigestion.

How does this happen and why is it a problem?

When substances move to the blood from the gut by slipping around
intestinal cells, they bypass the regulation that is present when
these same substances move across through the inside of these cells.
Intestinal cells can control the quantity that crosses. They do
this by regulating the number of transporters or carriers that span
the cell membrane and allow that particular substance into the cell.
After a substance crosses the cell to the blood side, it can leave
the cell to join the blood using a different set of transporters that
are on the blood or “exit” side. These transporters are
very specific for particular chemicals or nutrients.

Because intestinal cells control admission and exit from both the
gut and blood side, that’s why the body can send signals to these
cells instructing them whether to absorb more or absorb less of a
substance from food. So cells can erect barriers, if you will, to
prevent too much of a substance to cross, and this regulation can
protect us.

Unfortunately, the body loses that regulation when substances are
absorbed through the “leaky” junctions BETWEEN cells.
Oxalate is just one of the unfortunate substances where unregulated
absorption is a problem. At least now we know about oxalate, but
other things in food may also be a problem, like gluten, and for
some, casein, or allergenic foods.

Whenever more oxalate is absorbed like this, the result is
increased levels of oxalate in blood and urine and in tissues. More
of it stays in the bone than anywhere, but it also goes into blood
vessels, and glands, and secretory organs and even the spleen and
heart. It can even get into the brain, most likely the parts of the
brain that regulate hormones!

Hyperoxaluria

When scientists or doctors measure oxalate being high in urine,
they call this hyperoxaluria. Unfortunately, oxalate may be high in
blood or tissues when it isn’t high in urine. This is a serious
limitation of urine testing, because it doesn’t tell us when people
may have trouble secreting oxalate to urine. In that case, more
oxalate may be retained in the body than the urine test suggests.
Our almost exclusive reliance on urine tests is one reason scientists
haven’t sufficiently studied oxalate-related conditions in the rest
of the body when their patients had no obvious kidney disease.

Our bodies can also make oxalate

Eating foods high in oxalate is not the only way for oxalate to
get high in cells and blood. Our bodies make oxalate on their own,
especially when certain enzymes aren’t balanced in their activity
because of genetic differences or because someone has deficiencies in
enzyme cofactors like vitamin B6, magnesium or thiamine. Oxalate also
can be generated in the body when someone is getting high doses of
vitamin C or consuming high levels of fructose.

Protections from oxalate

Normally, when oxalate travels through the gut, it may encounter
particular species of bacteria which will digest it and turn it into
something else that isn’t so irritating and harmful. This system of
microbial digestion of oxalate may be why the body seems to
purposefully route excess oxalate from the rest of the body to the
gut for disposal. Unfortunately, the very microbes we need to do this
digesting of oxalate for us are subject to being killed by
antibiotics in common use. (see link) Even if there was no exposure
to antibiotics, these microbes might not have colonized in very young
children. The main oxalate degrading bacteria, oxalobacter
formigenes
, does not tend to be present in breastmilk, but
scientists think it must be picked up gradually from the environment.

Lactobacillus acidophilus deprived of its usual food, may
be able to “eat” oxalate, but too much oxalate in its
diet may kill it off. This may explain why certain people have great
difficulty colonizing lactobacillus acidophilus, despite
constant use of probiotics containing it.

Fortunately, a probiotic formulation of a bacteria called
oxalobacter formigenes is under development as a drug for
patients with hyperoxaluria and related conditions, and it is
currently in clinical trials, but may not be available until 2012 or
2013.

How do oxalates function in the body?

Scientists had wondered if oxalate might help to manage calcium in
the endoplasmic reticulum, but more recent studies see its role there
as more of a disruption. We just cannot find evidence that oxalate
has a beneficial reason to be high in humans, or that human
metabolism ever increases making oxalate to fulfill some need. Some
people have proposed using oxalate (similar to how doctors use
poisons in chemotherapy) to treat cancers “naturally”,
but they are probably not familiar with how this has already been
studied, and oxalate released from a chemotherapy drug called
oxaliplatin was found to produce serious neurotoxicity in those
patients!

Recent research on the management of oxalate trafficking in the
gut and other secretory tissues is suggesting that excess oxalate
secretion could end up involving changes in the regulation of fluid,
pH, microbial defense, and antioxidant protection. The gut seems to
be designed to eliminate excess oxalate, but perhaps when oxalate
levels in the blood get much higher than what our bodies expect, then
the excess oxalate may disrupt ordinary functions in the gut.

At this point, mainstream oxalate scientists (and they are almost
exclusively kidney doctors) are still thinking that the gut’s
problems are the CAUSE of oxalate absorption resulting in damage to
the kidney, but they are not yet willing to consider that the gut
itself and its function may also be a victim of the excess oxalate
coming from the blood even when the kidneys are not obviously
diseased.

Oxalate problems outside the kidneys

Now that we have six years of experience in reducing oxalate in
more than 3500 people in the support group associated with this
website and in more people indirectly through their physicans, it
seems clear that those who have had gut issues and reduce dietary
oxalate are often seeing their gut function improve or normalize as
they lose other chronic problems.

Many who reduce dietary oxalate, but had NO obvious kidney issues,
are seeing major improvements in other chronic conditions.
Scientists must start looking with fresh eyes at these other
conditions and their potential association to oxalate. So far, our
list of conditions that improve includes fibromyalgia, interstitial
cystitis, vulvodynia, depression, arthritis, and gut problems of all
sorts, as wells as autism and many other developmental disorders.
Some of these disorders have clear genetic links, but the gene
defects may produce “leaky guts”, or oxalate problems all
by themselves without the requirement of inflammation.

Scientists know that issues local to the kidneys raise risks for
kidney stones. They also found out that urine oxalate levels in
those with kidney stones do not tend to be very different from urine
oxalate levels in the rest of us. Even so, reducing dietary oxalate
can help reduce stones, especially if other treatments did not help.

Kidneys provide only one site of oxalate secretion, but oxalate is
also secreted to skin, to saliva, to mucus in the lungs, and to the
gut and stool. The relative importance of these other modes of
secretion have not been adequately studied. Risk factors relevant to
these other systems may account for why some people with oxalate
issues do not have kidney stones or other signs of kidney disease,
but may have serious effects in other places from an excess body
burden of oxalate.

The body has antioxidant and other protections against oxalate
which work when the body burden of oxalate is low and the antioxidant
resources high. These systems may be overwhelmed by higher levels of
oxalate in the body’s tissues, or when infection (frequent
immunization?) overwhelms the body’s antioxidant systems. For this
reason, as long as someone continues to consume a high oxalate diet
when their gut is “leaky” or when they are sick, then,
eventually, in time, the damage may begin to appear as some organs
begin to be affected by a buildup of oxalate, or by the disruption of
the mineral chemistry that oxalate may inflict.

Why do plants have oxalate?

So why does nature put oxalate in plants that we might eat?
Plants use oxalate to protect themselves from infection or from being
eaten. Oxalate crystals can tear up the “teeth” of the
bugs that eat them, and the bugs will stop and leave the plant alone!
That’s why oxalate is a good protection for plants that taste good
to bugs, but they are a secret surprise for larger creatures who
don’t detect oxalate when they eat high oxalate foods, and who lack
the ability to sense its toxicity and lack the means to protect
themselves from oxalate’s effects. There is simply too much distance
between the time of consumption and the appearance of problems for
anyone to have noticed this issue until now when the proper science
is beginning to be done.

Fortunately, there are plenty of other plant foods that are
equally healthy as plants that are high oxalate. It is hard to learn
that plants previously thought to be highly nutritious, like spinach
and field greens, are extremely high in oxalate. In fact, spinach
and many nuts are also high in the poison, cyanide, and who told us
that?!

Now, since more testing has been done, we can enjoy eating the low
oxalate plants that have high nutrition without experiencing the
subtle, and insidious buildup of oxalate. We can be happy about
limiting our exposure to this clear antinutrient, mitochondrial
toxin, and disruptor of cell chemistry. Please feel welcome to
explore the rest of our site for more information!

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