Silica

Why silica is good for you

Silica is a trace mineral, which means the body only needs a very small amount of it to stay healthy.

Silica is found most predominantly in the connective tissues – skin, blood vessels, cartilage, bone, teeth, tendons and hair. Silica is really beneficial for the health of blood vessel walls (the aorta is has really high concentrations of silica).

Silica is used to keep bones, cartilage, tendons, blood vessels and artery walls healthy. It is also required by the nails, hair and skin to stay in good condition and is useful in counteracting the effects of excessive aluminium in the body, which is implicated in the development of Alzheimer’s disease.

Silica is also involved in the formation of healthy bone tissue and collagen, the framework which makes the body “stick” together, without which, the body would fall apart.

Important silica facts

• Silica is short for silicon dioxide
• Silica is also called silicon and is a natural substance while silicone is a man-made industrial substance which is popularly used in breast enlargement operations
• Silica is present in soil, plants and water
• Silica has a similar healing effect on cartilage and joint degeneration as sulphur
• Silica is important for the health of hair, skin and nails
• Silica is needed by the body to make the connective tissue collagen
• Water, as well as beer and coffee (both made with water) are the main ways most people get adequate intake of silica (over half of the daily intake).
• Beer can contain anywhere from 19-60mg silica per kg of beer (approximately 1 litre of beer), which provides adequate intake of silica, but it may not be a heart healthy decision to drink that much beer every day
• Some anti-caking and anti-foaming additives in foods are are made from silica
• Silica may help to counter the effects of too much aluminium in the body, which some studies suggest is implicated in Alzheimer’s disease

Silica works best with

• Vitamin D
• Boron
• Calcium
• Magnesium
• Manganese
• Potassium

Silica and health

• Ageing – silica levels drop as people age and it might therefore be beneficial as an anti-aging component in the diet of older people. In addition to this, silica helps to mitigate any adverse health effects that aluminium have on the body, in particular as a risk factor in the development of Alzheimer’s disease. Several studies show that silica may play a role in prevention of this disorder, but more studies are needed to confirm the results of initial studies
• Atherosclerosis – studies show that silica may play an important role in ensuring the blood vessels and particularly, the walls of arteries (which get clogged up in people with atherosclerosis) are healthy and functioning correctly
• Bone health – silica looks promising as a way to completely heal bone fractures as it in needed by the body to help with bone health and reduce risk of osteoporosis. While results from initial studies are positive, more research needs to be done in this area to confirm this ability

People who wish to take a silica supplement should talk to a medical professional before taking it.

Groups at risk of silica deficiency

Nobody has ever been found to be deficient in this essential mineral.

Symptoms of silica deficiency

It is unlikely that a silica deficiency would occur in many people, but if it did, it is thought that it may result in the following deficiency symptoms:

• Problems with the teeth and bones (decay and softening)
• Hardening of the arteries

Silica in food

Silica is also present in the following foods:

• Alfalfa
• Barley
• Beetroot
• Leafy green vegetables
• Millet
• Oats
• Onions
• Rice
• Whole grains
• Wheat

Silica recommended daily intake (RDI)

The tolerable upper limits should only be taken for short periods and only under medical supervision.

** The recommended daily intake for silica for infants, children and pregnant / lactating women has not yet been determined due to a lack of data about the adverse effects in this age group. The only source of silica intake should be from food.

* The tolerable upper limit for silica for infants, children and pregnant / lactating women has not yet been determined due to a lack of data about the adverse effects in this age group. The only source of silica intake should be from food.

† The recommended daily intake and tolerable upper limit are derived from the Nutrient Bible by Henry Osiecki. Studies also show that general human intake from food is between 30-50mg per day

The USDA does not give any values for either recommended daily intake nor for tolerable upper limit of silica and suggests that there is not enough data about safety of supplements and that dietary intake should be adequate.

§ The Food Standards Agency UK suggests that intake of silica supplements less than 700mg per day should not produce harmful side effects in most people, but you should be able to get all your silica requirements from your diet.

Toxic levels of silica

Silica is toxic at doses greater than 100mg.

Overdosage and toxicity symptoms

If silica supplements that are much higher than the tolerable upper limit are taken, then they can cause the following toxicity symptoms:

• Bruising
• Silicosis
• Skin rash
• Stomach irritation

People experiencing any of the above toxicity symptoms should discontinue their silica supplements and seek medical advice.

Silicon dioxide vs horsetail supplements

It is thought though, that silicon dioxide (silica) supplements are more toxic at lower levels than those from the herb horsetail, which can generally be safely taken at higher levels, but neither supplements should be taken at excessively high levels for long periods as they can cause toxicity symptoms. The type and severity of toxicity symptoms depends on the individual’s tolerance levels.

Long-term use or very high doses of horsetail (or silica) supplements have caused irreversible kidney damage, especially in people with existing kidney or heart disease. People with oedema (fluid retention) should also not take silica (or horsetail) supplements.

Overdosage and toxicity is more likely to occur from taking too many supplements, whereas dietary intake of silica is highly unlikely to cause overdosage.

Silicosis

Silicosis is a health condition that occurs when silica dust particles are inhaled. It causes an inflammation and scarring of the lungs, which causes fibrosis of the lungs. The silica dust enters the lungs and irritates them continuously and reduces the capacity of the lung, as silica does not dissolve over time. This condition can be a health hazard for people working with sandblasting equipment and who do not wear protective head gear.

It is also a problem that occurs when people are exposed to silica dust when working with engineered stone. It is such a big health problem that the use, supply and manufacture of engineered stone will be banned in Australian from 1 July 2024.

General warnings and precautions

Certain people should not take silica supplements:

• Women who are pregnant or breastfeeding
  Women who are pregnant or breastfeeding should not take silica supplements due to the unknown effect on the unborn foetus and young infant.There is also no recommended daily intake of silica for women who are pregnant or breastfeeding, due to the unknown effects on the child.

Other warnings

Studies show that diatomaceous earth industry workers who were exposed to crystalline silica during the course of the excavation and mining of diatomaceous earth have a higher than expected rate of death from cancers related to silica exposure and inhalation.

There is a lot of conflicting information about this mineral, so people who want to take a silica (or horsetail) supplement should always exercise caution. Seek advice from a doctor before trying any silica (or horsetail) supplements, especially at high doses.

Interactions with medications and supplements

The following are the medications and supplements that are more likely to cause a reaction with silica supplements:

• Aluminium
  Silica helps the body detoxify of excess levels of aluminium in the body, by binding with the aluminium and allowing it to be eliminated out of the body before it can cause any damaging effects.
• Calcium, magnesium, manganese, potassium
  Absorption and utilisation of silica is enhanced by the minerals calcium, magnesium, manganese, potassium

There are no adverse interactions between silica and medications

Other interactions with silica

There are none reported.

Silica’s effect on lab tests

There are none reported.

References

• Food Agency UK. Risk Assessment – Silicon. Accessed 15 January 2010
• Food Agency UK – Silicon. Accessed 15 January 2010
• Gillette Guyonnet S, Andrieu S, Vellas B. The potential influence of silica present in drinking water on Alzheimer’s disease and associated disorders. J Nutr Health Aging. 2007 Mar-Apr;11(2):119-24
• Murray M and Pizzorno J. Encyclopedia of Natural Medicine. Rocklin, CA: Prima Publishing, 1991
• Nielsen FH. How should dietary guidance be given for mineral elements with beneficial actions or suspected of being essential? J Nutr. 1996 Sep;126(9 Suppl):2377S-2385S
• Osiecki, H. The Nutrient Bible. Bio-Concepts Publishing QLD, 2002
• Park R, Rice F, Stayner L, Smith R, Gilbert S, Checkoway H. Exposure to crystalline silica, silicosis, and lung disease other than cancer in diatomaceous earth industry workers: a quantitative risk assessment. Occup Environ Med. 2002 Jan;59(1):36-43
• Rice FL, Park R, Stayner L, Smith R, Gilbert S, Checkoway H. Crystalline silica exposure and lung cancer mortality in diatomaceous earth industry workers: a quantitative risk assessment. Occup Environ Med. 2001 Jan;58(1):38-45
• Robberecht H, Van Cauwenbergh R, Van Vlaslaer V, Hermans N. Dietary silicon intake in Belgium: Sources, availability from foods, and human serum levels. Sci Total Environ. 2009 Aug 1;407(16):4777-82. Epub 2009 May 31
• Rondeau V, Jacqmin-Gadda H, Commenges D, Helmer C, Dartigues JF. Aluminum and silica in drinking water and the risk of Alzheimer’s disease or cognitive decline: findings from 15-year follow-up of the PAQUID cohort. Am J Epidemiol. 2009 Feb 15;169(4):489-96. Epub 2008 Dec 8
• Sivak O, Darlington J, Gershkovich P, Constantinides PP, Wasan KM. Protonated nanostructured aluminosilicate (NSAS) reduces plasma cholesterol concentrations and atherosclerotic lesions in Apolipoprotein E deficient mice fed a high cholesterol and high fat diet. Lipids Health Dis. 2009 Jul 28;8:30
• Trincă L, Popescu O, Palamaru I. Serum lipid picture of rabbits fed on silicate-supplemented atherogenic diet. Rev Med Chir Soc Med Nat Iasi. 1999 Jan-Jun;103(1-2):99-102
• Whitney EN, Cataldo DB, Rolfes SR. Understanding Normal and Clinical Nutrition, 6th Edition. Wadsworth/Thomson Learning, 2002
• US National Library of Medicine – Horsetail. Accessed 15 January 2010
• Australian Government Department of Employment and Workplace Relations – Prohibition on the use of engineered stone. Accessed 6 May 2024

Last updated: 6 May 2024