August 04, 2021 10 min read

In the age of industry, processed foods, and mystery ingredients, it’s good to be hyper-aware of what you’re putting in your body. This is no less true when looking at supplements for working out

Supplements are unique in a sense because they’re regulated by the Food and Drug Administration (FDA) as food, not drugs. This can become problematic when one considers some of the biological effects that supplements can have on the human body. Considering this, it’s important to ensure that you’re getting high-quality supplements that help you work towards your goals.

One of these mystery ingredients (at least for some people), is silica. You’ll often find it in processed foods, and even in silica packets found within certain items (such as shoes) that help to prevent a buildup of moisture. However, there’s a lot more silica than meets the eye. Although it’s common, it has some surprising benefits.

What is Silica?

First, let’s take a closer look at what exactly silica is. Also known as silicon dioxide (SiO2) or silicium, this mineral is a combination of silicon and oxygen. It makes up almost two-thirds of the Earth’s crust, and it’s a recognizable form of quartz.

Cluster of rock crystals or pure quartz, a clear macrocrystalline variety of silica (SiO2)

You’ll find it in water, animals, plants, and obviously the Earth.  Over 90% of rocks are made up of silica, and whenever you go to the beach, it’s silicon dioxide in the sand form that allows you to build sandcastles. But for our purposes, silica is naturally found in the human body.

Although we’re not sure exactly what roles it plays, we do know it’s important enough to be an essential nutrient—not to mention that it’s the third most abundant trace mineral in your body. It might be somewhat of a mystery, but we do know enough about it to recommend it.

However, not all silica is created equal. And if you’re coming here without previously knowing anything about it, then you probably have some negative ideas about silica. These are warranted, but they also don’t necessarily relate to the dietary version of the mineral.

Crystalline versus Dietary Silica

So, what are the different versions of silica? The one you’ve probably heard of the most is crystalline silica. It causes diseases such as silicosis, and potentially even lung cancer. Silicosis is a fatal lung disease that’s caused by inhaling this crystalline version. Those who work in mining, quarrying, construction, steelwork, or sandblasting, are all at a higher risk of developing this disease.

However, dietary silica (the type you ingest) is water-soluble, making it completely different from crystalline silica that you might inhale. Research has even shown that the small amount of silica we get from our diets doesn’t even stay in our bodies, but is rather expelled on a regular basis by the kidneys.

Other than being a supplement and used in various industries, it’s often a food additive used as an anticaking agent which helps prevent clumping. When found in supplements, it serves a similar purpose to prevent powders from sticking together and clumping.

Although not something that many people are familiar with, there haven’t been any studies showing negative effects from ingesting dietary silica. In fact, the mineral is actually found in many foods and this is where most of us get it from.

Foods that Contain Silica

Chemically, the silica found in supplements is the same or similar to the silica found in different foods. It’s especially common in any whole grains. For most people, the silica they get from their diet is enough, but some studies have shown that silica might have special benefits for the human body. We’ll look at these further below.

  • Cereals/grains: Out of the list of 18 foods with the largest amount of silica, 11 of these were grain products. To add to this, those grains that contained oats topped the list even more.
  • Green beans: Other than grains, green beans are some of the other most silica-rich foods out there. One cup of green beans has 7 mg of silica, which is roughly a third of the average American’s daily silica ingestion.
  • Lentils: Lentils, and especially red lentils, are very rich in silica. Just one teaspoon of red lentils can contain 1.7 mg of the mineral.
  • Bananas: An all-around healthy food, bananas also contain a significant amount of silica. A medium-sized banana has about 4.7 mg of silica in it.
  • Brown Rice: All rice contains some amount of silica in it, but brown rice contains the most (and brown rice is an overall healthier option than white rice). Three tablespoons of brown rice will contain 4.5 mg of the mineral.
  • Beer: Saving the best for last, we have beer. And not only do we say “best” because it’s beer, but also because it contains the highest ratio of silica per portion than any other drink or food. While the amount of silica will differ from beer to beer, lagers contain the highest levels of it.

The Health Benefits of Silica

As we mentioned above, silica is a somewhat mysterious mineral. While some research has been done on the topic, there’s still a lot of questions out there in terms of its effects on the human body.

However, it’s largely considered to be safe with no adverse effects, and in fact, there’s good reason to believe it even has positive health effects.

Silica for Your Bone Health

Strong bones sound good, but things are a little more complicated than simply having strong bones. There are two ways in which the strength of our bones is dictated. The first is the bone matrix quality, which deals with the bone structure and composition—other than the minerals involved. The second aspect is just this: mineralization.

The bone mineral density (BMD) is what dictates this part of bone strength. So, where does silica come into play? The mineral silica is important for the formation of collagen fibers, and collagen makes bone mineralization possible. But silica goes even further than just being a building block of collagen.

In one study, it was found that silica might even promote the growth of new bone cells, which are called osteoblasts. And if that’s not enough, silica has been shown to also potentially prevent the loss of bone. It does this by inhibiting the production of certain cells that break down bone—these are called osteoclasts.

While this bone breakdown is a normal part of your physiology, silica could potentially be used to counteract certain diseases that increase the rate of bone breakdown.

Silica, Skin, and Healthy Hair

Since we’re talking about collagen, we have to mention skin and hair as well. Along with providing collagen, silica also promotes the production of other components important for skin health. This includes elastin, which is important for giving your skin elasticity. In terms of hair health, silica aids in the production of keratin which is very important for the health of your hair and preventing hair loss.

Your connective tissues and ligaments will also stand to benefit. While studies are still not exactly sure how effective silica might be for these things, supplementing with it could make your hair less brittle and your skin more elastic, smooth, and hydrated. And if that wasn’t enough, silica might even help us to fight off cognitive decline and improve immune function.

Preventing Cognitive Decline

While this benefit is far from certain, there is some evidence that silica can help to prevent cognitive decline. The main mechanism behind this is the way it binds to aluminum. Aluminum is often found in deodorants and sometimes even water sources, and while some exposure to it can be tolerated by the body, it has a tendency to build up in some tissues.

This build-up (when it happens in the brain) has been linked to cognitive decline, especially in older populations. However, some studies have shown that silica is particularly good at binding with the aluminum inside of the body. When it binds in this way, it helps prevent the aluminum from being taken in through the gastrointestinal tract. This also hints that silica may be good for digestive tract health.

Improving Immune Function

Along with the above, silica may also be good for our immune systems.

For one, silica is an anti-inflammatory agent, which already makes it a great supplement for preventing free radicals in your body. Free radicals are linked to increased chances of certain diseases, so silica could potentially be an important immune booster.

Other than this, silica can also be important for preventing heart disease. While the evidence is sparse, some studies have suggested that silica may help your heart and arteries as well. It does this by lowering cholesterol and also helping to reduce the hardening of arteries, which is called atherosclerosis.

Silica may also reduce the risk of developing degenerative diseases. All of these potential benefits are important for aging populations. However, it is important to note that silica hasn’t been that widely studied. Although research exists, some of the bigger benefits are still kind of spotty in terms of evidence. However, there is a lot of evidence that silica doesn’t harm the body, so there’s no harm in trying.

How Much Silica Should You Take?

While there is no recommended daily allowance (RDA) for silica, there are some good guidelines to follow. The research largely supports getting at least 22 mg of silica every day, for example. And if you’re an adult who’s eating a healthy diet with a lot of plants, you’ll probably be consuming 14 to 62 mg per day.

This depends largely on the person and the source you’re looking at, but an ideal daily dose of silica comes in between 180 mg to 360 mg. Of course, this depends largely on your age, diet, goals, and physiology. While silica has been studied, there are few cut-and-dry aspects to supplementing with it.

For example, taking silica for bone strength necessitates a dose between 30 and 45 mg per day. To further complicate matters, we also need to consider that the mineral silica is 54% oxygen by weight. If you’re looking to get enough for the bone benefits, then 65 to 100 mg is what you should really be aiming for.

So, how much is too much? There hasn’t really been a studied upper limit for silica supplementation, but everything is best in moderation. When it comes to silica, 700 mg per day is an often-cited absolute highest dose.

Put another way, silicon dioxide shouldn’t make up more than 2% of a food’s weight. However, this is mostly due to the fact that higher doses haven’t been studied. But this also depends on the source of your silica, as we’ll see below.

Silica Supplements

This underscores the complexity when it comes to choosing different silica supplements and what they can mean for you. When choosing a supplement, look at the dosage as well as the source of the silica, the delivery method, and the purity of the silica. We’ll get more into the source of silica down below, but the delivery method warrants mentioning.

Silica supplements will most commonly come in either tablet form or liquid form. There are strengths and weaknesses to both, but the tablets tend to come out on top because it’s easier to get an exact dose. With a liquid, there’s always some guesswork involved unless you’re using extremely precise measuring techniques.

Silica Si, dietary supplement.

But on the other hand, tablets are more likely to also include different fillers and binders. The binders are a given since the tablet needs to stick together somehow. But fillers should be avoided unless you’re taking a supplement that’s advertised to have several different beneficial additives.

These are all things you need to consider when looking for supplements, and this goes for much more than just silica. The last thing to consider is the source of your silica, which ties into the risks.

The Risks of Silica

Like we mentioned at the very beginning, crystalline silica is a big no-no. Inhalation of it has been tied to lung cancer and other respiratory diseases. This often happens to those in the mining, construction, steel, or sandblasting industries. Obviously, this isn’t the way to go if we’re trying to supplement with it.

Dietary silica is considered safe for those who are overall healthy. It should also be mentioned that the silica that we consume doesn’t stay or accumulate in our bodies, but it’s rather flushed out by the kidneys. All in all, the supplement itself is regarded as safe. However, there are other things to consider.

The biggest consideration when looking at safety is the source of the silica. For example, many silica supplements are herb-based, and these herbs can have other biological effects on you. Horsetail extract is often used as a source of silica, but it’s also a diuretic. This means that it can remove too much potassium from your body, potentially interfering with other medications related to heart rhythm.

Horsetail also contains the enzyme thiaminase. This doesn’t matter too much for most people, but this enzyme does destroy vitamin B1. For those who are already deficient in vitamin B1, horsetail supplements can cause symptoms of neurological toxicity. Also keep in mind that some supplements have this enzyme removed, making it safer.

If you’re not sure, it’s best to take a vitamin B complex or ask a health care practitioner. Other sources of silica include horse chestnut and bamboo, but there are also synthetic sources. Another source is red algae, which is more expensive but avoids some of the pitfalls of horsetail supplements. 

Who Should Supplement with Silica?

Chances are that most of us already get enough silica in our diets, but there are some populations that might want to consider taking a little more of it through supplements.

Due to silica’s effects on strengthening bone density, the aging population over 45 should consider taking a silica supplement, in order to prevent bone breaks. Those who are looking to improve skin and hair health can also consider taking a silica supplement in order to improve health in these areas.

Silica and Holistic Wellness

When it comes to silica—and all supplements for that matter—it’s important to ask why you’re taking it. Has it been prescribed? Are you trying to fill in a dietary gap? Improve your performance in the gym? Increase the health of your immune system? Taking supplements for the sake of taking supplements tends to be a waste of money and can possibly lead to overlooking dietary needs.

Supplements should never replace the food you’re eating unless you have a dietary requirement that prevents you from getting the necessary nutrients. This isn’t to say that supplements don’t have their place in a healthy lifestyle, but they should be taken with intention and the knowledge of what they do.

Once you have some background knowledge on what you need, supplements can be powerful tools to reshape your wellness. Silica can just be another tool in your tool belt, whatever your goals are. Want to make your bones stronger, or improve your immune health?

Silica can pull its weight, taking your wellness to new heights.


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