Diatomaceous Earth vs Horsetail Grass
Silica is essential to the body,
especially for the production of structural proteins
including collagen and elastin. Structural proteins
help give strength and elasticity to the hair, nails,
bones, cartilage, tendons, ligaments, blood vessel
The body does not absorb and utilize silica in the
form of silicon dioxide. Instead, silica reacts with
water to form small amounts of orthosilicic acid (OA),
which is absorbed by both plants and animals for the
formation of tissues. Although OA is not “silica”
(silicon dioxide) in the scientific sense it is still
referred to as silica. Especially when referring to
OA in plants.
The presence of acid increases the conversion of
silica in to OA. In the body the primary acid source
is stomach acid. Stomach acid declines with age though.
This decreases the body’s ability to produce
and absorb OA leading to loss of tissue integrity
and elasticity frequently associated with “aging
disorders”. The use of acid blockers or antacids
such as acid heartburn medications, coral, dolomite,
oyster shell or alkaline waters can further inhibit
the production and absorption of OA.
Primary dietary sources in animals for OA include
mineralized water and fibers. OA is formed in natural
water sources as water dissolves small amounts of
silica in soils and rocks forming OA. OA in water
is also taken up by plants where OA helps to give
plants strength by incorporating as part of their
fibers. When these fibers are ingested the OA in the
fibers can be extracted for use by the body.
Horsetail grass (shavegrass) is often incorrectly
referred to as the highest herbal source of “silica”,
as OA. The fact is that bamboo stalk is 7 times higher
in silica than horsetail grass.
Diatomaceous earth (DE) is another excellent source
of silica, and also contains much higher levels of
silica than horsetail. DE is the skeletal remains
of phytoplankton and consists of 80% silica compared
to the average 4% silica content for horsetail grass.
As an herbalist I really do not recommend the use
of horsetail grass as a silica source for several
Some species of horsetail are very
Even the less toxic forms of horsetail
grass can cause problems with long term use including
nervous system disorders, headaches, loss of appetite
and premature labor. In moderately high doses, or
as a concentrate, horsetail grass can cause strong
contractions of the blood vessels inhibiting blood
flow to tissues.
Horsetail grass contains the
enzyme thiaminase and the toxic alkaloid equisitine,
both of which deplete thiamin from the body.
Symptoms of thiamine deficiency include depression,
lack of appetite, diarrhea, loss of muscle control,
arrhythmias and tachycardia. Tinctures of horsetail
pose even a greater risk as fresh plants are
frequently used to make tinctures. Fresh horsetail
contains higher level of toxic thiaminase and
alkaloids. Thiaminase in particular is suspected
in the poisoning of livestock ingesting horsetail
grass. Although these poisonings are more likely
due to toxic alkaloids, such as palustrine in
horsetail grass, since ruminants can produce
thiamine in the rumen.
Thiaminase has also been shown to
be toxic to the liver.
Even though the amount of nicotine
in horsetail is small, it does not take much nicotine
to cause harm. Nicotine is one of the strongest
central nervous system poisons known to man. It
only takes 5mg to kill an adult human. To understand
how small the amount really is needed to kill an
adult consider the average single ‘O’
capsule normally used for capsuling herbs holds
an average of 500mg. Because nicotine is also a
powerful constrictor of blood vessels much lower
levels can still be especially dangerous for some
individuals. People with poor circulation to begin
with such as diabetics, people with heart disease/failure,
people with hypothyroidism and people with Raynaud’s
disease or Raynaud’s phenomena are all more
prone to the dangerous blood vessel constricting
effects of horsetail grass.
Horsetail grass is contradicted
with the use of diuretics to prevent abnormally
low potassium levels and stimulants like caffeine
to prevent over stimulation of the nervous system.
It is not clear if nicotine is the only component in
horsetail grass that constricts the blood vessels. Other
alkaloids present in horsetail may also contribute to
As an example of this effect a friend of mine was a
fitness trainer in excellent shape. After drinking 2
cups of horsetail tea she went to bed. She woke up shortly
afterward ice cold because the horsetail grass tea had
constricted her blood vessels decreasing her blood flow.
If a herbal source of silica is desired the best choice
is bamboo stalk, which unlike horsetail grass dilates
blood vessels. This makes bamboo a much safer choice
for people with high blood pressure, conditions that
reduce circulation or that are on contradicted medications.
Other safe sources of silica include nettle leaf, oat
straw and seaweeds.
A better choice though is food grade DE. DE is higher
in silica than herbs and does not contain any toxic
enzymes or alkaloids as in the case of horsetail grass.
Silica is poorly absorbed, but there are ways to increase
levels in the body, even when stomach acid is low. A
simple method is to add a spoon full of food grade DE
to a gallon of water and allow the DE to settle to the
bottom. This may take a few days initially. Pour the
water you intend to drink from the top of the container,
but be careful not to disturb the DE on the bottom of
the container. Refill the container with water and allow
it to settle out again. Keep repeating this process.
A spoon full of DE should last several years if it is
not poured off in the water.
There are several advantages to this method. First
of all, small amounts of the silica in the DE are dissolved
in to the water every time new water is added forming
OA. Secondly, because silica is poorly absorbed only
a fraction of the silica from silica supplements will
be absorbed. In addition, people will not take silica
supplements as often as they will drink water each day.
Adding the silica to water results in the formation
of OA of which small amounts are absorbed each time
a drink of the water is taken. This leads to significantly
higher levels of OA absorption from drinking the water
throughout the day compared to taking an occasional
Is DE Toxic?
Anything can be toxic is sufficient quantities or if
used improperly. DE is only toxic though if inhaled
repeatedly over long periods of time, which can lead
to silicosis. This is actually a potential problem with
other silica sources as well such as clays, which are
formed from the weathering of silica containing rocks.
Ingested DE has not been shown to be harmful though.
In fact, DE has a long history of use in silica supplements
and being ingested to eliminate intestinal worms in
animals and people with no adverse effects.
The reason DE kills intestinal worms without harming
the intestinal wall is simple. Intestinal worms have
much thinner and delicate tissues than the human digestive
system. Worms therefore are prone to the abrasive effects
of DE, unlike the human gastrointestinal tract. In fact,
DE is considerably less abrasive than the fibers we
ingest in our diets, which are less abrasive than horsetail
grass. Horsetail grass is so abrasive that it is also
known as scouring rush for its use in the pioneer days
to clean pots and pans.
DE is only slightly abrasive being more like ultrafine
sandpaper used for polishing. For this reason it is
commonly used in toothpaste to safely clean teeth.
Other common uses of DE are:
• Insect control in foods we consume.
• As an anti-caking agent in foods.
• An addition to animal feeds to keep livestock
worm free without toxicity.
• In cosmetics as a filler, opacifier and scrub
agent since DE is not toxic and it will not harm the
• As an additive to some soaps.
• As a flow agent and filler for the manufacturing
of capsules and pills since it does not harm the digestive
Myths About DE
Myth: DE is “agatized”
silica and has a hardness of 7 on the Mohs hardness
scale making it hard on the tissues.
Fact: This false claim is based on
the hardness of pure silica, which has a hardness of
7. DE is not pure silica though. It is comprised of
80% silica, 10% metal oxides and 10% moisture. The actual
hardness of DE is actually quite low, 1 to 1.5 on the
Mohs hardness scale, which runs from 1 (the softest)
for talc to 10 (the hardest) for diamond. This can be
verified on this link showing the hardness for various
materials on the scale:
Another way to look at this is bentonite clay is a
weathering byproduct of rocks, and like DE contains
silica and smaller quantities of other minerals. Despite
the content of silica, bentonite has nowhere near a
hardness of 7.
As for the claim that DE is agatized silica, again
this is not true. Agate is formed from extremely hot
water supersaturated with silica, and possibly some
magmatically dissolved silica. This dissolved silica
deposits in to crevices or vugs within rocks or replaces
organic matter in items such as shells or wood creating
layers of hard silica.
Again, DE is the skeletal remains of phytoplankton
that have died and settled to the bottom of ancient
oceans and lakes. These phytoplankton, nor their remains,
were ever subjected to extremely hot water or magma
to dissolve the silica and redeposit it as a quartz
such as agate.
Food grade DE is extremely soft having a hardness of
1-1.5, as pointed out earlier, far below the hardness
of pure silica that has a hardness of 7. In addition,
food grade DE consists of amorphous, not crystalline,
silica. Amorphous silica is not as hard and sharp like
crystalline silica and does not pose the same health
risks as crystalline silica.
Clumps of DE are also sold as kitty litter. If DE was
so sharp and hard as claimed, cat’s paws would
be shredded from scratching in the litter box. Of course
this is not the case since the claims about DE being
hard and sharp to the point of damaging tissues are
Myth: Consuming silica causes kidney
Fact: I have heard people claim that
they got kidney pain within minutes of ingesting DE.
It is hard to say why they experienced this problem,
but it was not from the silica in the DE as I have seen
claimed. A simple fact of anatomy and physiology can
prove this. Once ingested, the silicon dioxide in the
DE has to convert in the stomach in to OA in order to
be absorbed. When the stomach finally empties its contents
in to the in intestines the OA can be absorbed. Next
the OA circulates through the blood where most of the
OA is utilized in the formation of tissues. Finally
traces of OA can reach the kidneys for safe excretion.
No damage occurs to the kidneys since the OA is not
in a solid crystalline form that can cut thinner tissues
of the kidneys. The whole process for the traces of
OA to be absorbed and even smaller traces to reach the
kidneys takes considerably longer than the few minutes
people are claiming to get pain within.