I ran into an article that connects several of my recent ‘themes’. From beer, to things that contribute to kidney stones, to how the element silicon is used in life and metabolism. The major thrust of the article is directed at bone growth and how dietary silicon is important to proper bone growth, but along the way it finds some other interesting connections.
One, which I found rather interesting, was that beer is a major source of bio-available silicon. While this might have something to do with their funding ( I’ve become more sensitive to questions of funding thanks to the Global Warming hysteria showing folks willing to create outcomes for funding…) the article does look to be honest and well supported.
At the bottom it notes:
The Frances and Augustus Newman Foundation and the charitable foundation of the Institute of Brewing and Distilling for their support.
Then again, it finds low availability of silicon from distilled spirits…
But it does find that beer is a very good source.
The intake within different age groups is not well documented (33). It appears to be similar for children (27 mg/day) and adults (29 mg/day) in Finland, although their major sources of intake are different (32). In children the major source is from cereals (68% of total dietary intake), whereas the major source in adult males is from beer ingestion (44%) (30, 32). Intake in females is lower than in males, which is due to the higher intake of beer in males (30, 32, 36). Beer is a highly bioavailable natural source of silicon (see below). Intake also decreases significantly with age in adults (0.1 mg for every additional year) (30, 33).
So I guess one could argue for old folks having a few beers to support good bone growth… but they also make it pretty clear that a bowl of cereal does a good job too.
Somehow I don’t think we’re going to see roving bands of old women carting six packs of beer and leering at boys, just so they get stronger bones.
The article doesn’t find exactly how silicon is used in the body ( I’ve yet to find an article that does). But it finds a fair amount of circumstantial evidence for silicon involvement in the growth and production of collagen and bones. Including some studies that did silicon deprivation in lab animals and got weak collagen and weak bones. As another source of silicon is hard water, I’m also left wondering to what extent folks drinking more filtered, softened, and silicon reduced water might have contributed to various increases in bone and connective tissue problems.
Low bone mass (osteoporosis) is a silent epidemic of the 21st century, which presently in the UK results in over 200,000 fractures annually at a cost of over one billion pounds. Figures are set to increase worldwide. Understanding the factors which affect bone metabolism is thus of primary importance in order to establish preventative measures or treatments for this condition. Nutrition is an important determinant of bone health, but the effects of the individual nutrients and minerals, other than calcium, is little understood. Accumulating evidence over the last 30 years strongly suggest that dietary silicon is beneficial to bone and connective tissue health and we recently reported strong positive associations between dietary Si intake and bone mineral density in US and UK cohorts. The exact biological role(s) of silicon in bone health is still not clear, although a number of possible mechanisms have been suggested, including the synthesis of collagen and/or its stabilization, and matrix mineralization. This review gives an overview of this naturally occurring dietary element, its metabolism and the evidence of its potential role in bone health.
Keywords: Silicon, orthosilicic acid, human exposure, dietary sources, silicon metabolism, bone health
It then proceeds to do just the overview it promises.
Some High Points
Along the way it touches on the bad side of silicon too. How breathing in a lot of silicon minerals can cause collagen formation and fibrosis forming diseases in the lungs, for example. It also turns out that high silicon can increase the tendency to kidney stones:
In modern pharmaceuticals Si is present mainly in antidiarrhoeals, antacids and in proprietary analgesics such as aspirin. In analgesics, silicates (magnesium silicate and magnesium trisilicates) are present as excipients, which are inert ingredients that hold the other ingredients together, or as desiccants, if the active ingredient is hygroscopic (37, 52, 58). The levels of silicates in these drugs, however, are not well documented and bioavailability is suggested to be negligible. Abusive use, however, can cause inflammation of the kidneys termed ‘analgesic nephropathy’, but it is unclear if this is related to the active ingredient or the excipient
Long-term use of high doses of silicate containing drugs, such as analgesics and antacids (magnesium trisilicates) could cause damage to the renal kidney tubules and lead to chronic interstitial nephritis (63). As noted previously, the high levels of silica in these drugs can lead to the formation of renal stones/calculi which are responsible for kidney damage. Formation of silica stones/calculi (urolithiasis) is also a common problem in cattle and sheep who ingest large quantities of silica daily, since grass consists of 2% silica by weight, and drink very little water (22, 37). However, ingestion of amorphous silica is not associated with toxicity in the rat (33).
So one needs to watch the analgesic consumption… But that also raises the question of “To what extent to they make arthritis feel better due to the pain medication and to what extent due to better collagen formation from the silicates?” Still, if you are a ‘stone former’ best to watch for silicate on the pill bottle ingredients list.
There is a mention of silicon substituted artificial joints having better bone formation (likely due to an early collagen matrix formation in the silicon activation sites).
All in all, it looks like silicon causes or is helpful in collagen formation and thus the tissues that depend on it. ( Along with having too much of it when mineral silicates are left in long term contact with soft tissues such as lungs).
Oral ingestion of crystalline or amorphous silica/silicates in the diet may also cause toxicity. The inflorescences of Steria italica (millet) promotes oesophageal cancer, while the seeds of the Phalaris family of grass (e.g. canary grass, Phalaris canariensis) promote skin tumours (42, 124, 125). Finely ground silicate minerals from eroded acid granite in drinking water has been linked to ‘Endemic or Balkan Nephropathy’, which is inflammation of the kidneys (interstitial nephritis), found in confine parts of the Balkans (Yugoslavia, Bulgaria and Romania) (63).
That connection to Balkan Nephropathy may also give a clue as to how the plant toxin that seems to cause most of the problem might operate. It might be an interference in the pathways that use silicon.
But what about evidence of importance? Well, it is found in different tissues in different amounts. The excretion tends to be proportional to calcium excretion. Take it away and bad things happen… Also added silicon correlates with better bone growth in living animals, people, and cells in the lab.
Tissue levels however vary. In the rat highest levels are found in bone and other connective tissues such as, skin, nail, hair, trachea, tendons and aorta and very much less (10-20 fold less) in soft tissues (19; Jugdaohsingh et al., unpublished data). A similar tissue Si distribution is expected in humans, although this has not been investigated. Silicon is suggested to be integrally bound to connective tissues and their components and to have an important structural role (82) as silicon deprivation studies have reported detrimental effects on these tissues (16,17) as is also speculated to occur with normal ageing with the decline in tissue Si levels. Vice versa, silicon supplementation has been reported to have beneficial effects on these tissues especially bone where much of current work has concentrated (36,48,54-56, 83-86). The potential importance of Si to bone health is discussed below.
Silicon deprivation experiments in the 1970’s, in growing chicks (17) and rats (16), suggested that silica may also be essential for normal growth and development in higher animals, including humans, primarily in the formation of bone and connective tissues. However, these results have not been subsequently replicated, at least to the same magnitude and thus the essentiality of Si in higher animals remains questionable.
Dietary silicon intake and BMD
As mentioned above, the main and most important source of exposure to silicon is from the diet and recently two cross-sectional epidemiological studies from our group have reported that dietary silicon intake is associated with higher bone mineral density (BMD). In the Framingham Offspring cohort we reported that higher intake of dietary silicon was significantly positively associated with BMD at the hip sites of men and pre-menopausal women, but not in post-menopausal women (36). This study was repeated using the APOSS (Aberdeen Prospective Osteoporosis Screening Study) cohort, a women only cohort, and it similarly showed that dietary silicon intake was significantly positively associated with BMD at the hip and spine of pre-menopausal women. We also showed a similar correlation in post-menopausal women but only in those currently on hormone replacement therapy (HRT) (94). A weaker (non-significant) correlation was found in past-HRT users and no correlation in those who had never taken HRT. These two studies suggest that higher silicon intake is associated with higher BMD, a marker of bone strength, and also, a potential interaction between silicon and oestrogen status.
No silicon deprivation studies have been conducted in humans, but, as described above, in laboratory animals Si deprivation resulted in skeletal abnormalities and defects. In chicks, legs and beaks were paler, thinner, more flexible and thus easily fractured (17). In rats, defects to the skull including the eye sockets was reported as was disturbances and impairment to incisor enamel pigmentation (16). More recent studies by Seaborn and Nielsen (95-100) (see Table 5) and others have not been able to reproduce these dramatic effects but have reported decreases in BMD, mineral content and collagen synthesis, and increases in collagen breakdown, thus confirming Si deprivation has a negative impact on bone.
There are also a couple of charts in the article that are worth looking at. For example, this is a bit from Table 6:
Human Osteoblast Cells
Brady et al. (115) From trabecular bone & MG-63 cell line (Zeolite A; 0.1-100 μg/ml) ↑: Cell proliferation (124-270%), ALP activity (144-310%)
Mills et al. (116) Zeolite A ↑: Cell proliferation & extra cellular matrix
Keeting et al. (117) From trabecular bone (Zeolite A; 0.1-100 μg/ml) ↑: Cell proliferation (62%), ALP (50-100%), osteocalcin (100%)
The up arrow means “increases”.
So you get some real measured science done, too.
Looks like folks with collagen or bone density issues ought to be eating their cereal, drinking water ‘on the rocks’ – literally, and maybe having a beer or two.
In vitro cell culture studies
Numerous cell and tissue culture studies have also been conducted to determine the mechanisms of silicon’s effect on bone (Table 6) (109-119). Studies by Carlisle in the early 80’s using chondrocytes and tibial epiphyses from chick embryos reported that silicon increased bone matrix synthesis (non-collagenous matrix polysaccharides and collagen) and that Si dose dependently increased prolyl hydroxylase activity, the enzyme involved in collagen synthesis (109-114). Recent studies with human osteoblast cells and zeolite A, an acid labile aluminosilicate, reported increased osteoblast proliferation, extracellular matrix synthesis, alkaline phosphatase (ALP) activity and osteocalcin synthesis (115-117). More recent studies using orthosilicic acid have also reported increases in type I collagen synthesis and cellular differentiation (118) and in addition increases in the mRNA of these proteins, suggesting potential involvement of Si in gene transcription (118, 119).
Thus tissue and cell culture studies have also suggested that silicon is involved in bone formation by increasing matrix synthesis and differentiation of osteoblast cells. Effects of silicon on bone resorption and osteoclast cell activity has not been well studied. Schutze et al (120) reported that zeolite A, but not separately its individual components (Si and Al), inhibited osteoclast activity (pit number and cathepsin B enzyme activity).
There’s even a bit of a connection to Egyptian Liquid Stone. Earlier I’d speculated on the potential to make a poured stone via high alkaline treated silicates and sand. This article confirms some of the silicon chemistry that ought to be involved as it looks at how silicon is mobilized from rock into the diet:
Silicon (Si) is a non-metallic element with an atomic weight of 28. It is the second most abundant element in the Earth’s crust at 28 wt %, (19, 20) but it is rarely found in its elemental form due to its great affinity for oxygen, forming silica and silicates, which at 92%, are the most common minerals. Quartz (12%) and the aluminosilicates, plagioclase (39%) and alkaline feldspar (12%) are the most prevalent silicates (21). These are present in igneous and sedimentary rocks and soil minerals and are highly stable structures that are not readily broken down except with extensive weathering. Thus natural levels of soluble (available) silica are low. Chemical and biological (plants, algae and lichens) weathering, however, releases silicon from these stable minerals, increasing its bioavailability. Dissolution of Si, from soil minerals in water results in the formation, by hydrolysis, of soluble silica species. Below pH 9, and at a total Si concentration below 2 mM, silicon is present predominately as Si(OH)4 the most stable specie at low Si concentration. This monomeric form of silica, ‘monomeric silica’, is water soluble and a weak acid (pKa of 9.6), thus also referred to as ‘monosilicic acid’ or ‘orthosilicic acid’ (22). At neutral pH, this tetrahedral, uncharged (i.e. neutral) species is relatively inert, but does undergo condensation reactions (polymerisation) to form larger silica (polysilicic acid) species, especially at Si concentrations > 2-3 mM. Indeed, only in very dilute solutions, it is suggested, that the monomer will be found in its pure form, as often the dimer [(HO)3Si-O-Si(OH)3] is also present (but never > 2%), even in solutions greatly below 2 mM Si (22, 22). Above 2 mM Si, Si(OH)4 undergoes polymerization to form small oligomers (linear and cyclic trimers and tetramers or cyclic decamers) and, at concentration much above 2 mM, small colloidal species will also be present, which upon aggregation will eventually results in the formation of an amorphous precipitate, which at neutral pH (pH 6-7) is a gel (20, 22-24). Thus polymerisation of Si(OH)4 reduces its solubility and hence bioavailability.
All of which implies that a silicate sand, treated with highly alkaline solution, ought to form some soluble silicon compounds; then ‘polymerize’ some silicate back between the sand grains when allowed to dry and neutralize the pH.
Silicon looks to me like a very under appreciated element. We tend to think of it as part of rocks and electronics, but not much else. It really is much more than that. We need it to grow and live.
Given the impact on collagen and bones, it may well be that the silicon in beer justifies calling it ‘healthful’. (The article notes that no such high silicon level is found in wine or distilled spirits).
Could it be that the Egyptians, treating beer as medicinal and making giant structures out of what some folks claim is poured stones; and with a burial inscription on a great architect’s tomb claiming he new the secret of liquid stone; could they have just known more about silicon and it’s uses than we do?
Earlier I’d done a bit of an overview of silicon in life:
But that was more directed a things like diatoms and bamboo. Turns out we need to think of it as a food and medicine, as well as a structural material.