When you look on a food or supplement ingredients list, you often see things you’ve never heard of, some of them you can’t even pronounce. Though many of these ingredients may seem alarming (and some with good reason), others are safe and it’s merely their name that is off-putting. Silicon dioxide is one such ingredient, found in many products, though often misunderstood.
What Is It?
Silicon dioxide (SiO2), also known as silica, is a natural compound made of two of the earth’s most abundant materials: silicon (Si) and oxygen (O2).
Most often recognized in the form of quartz, silicon dioxide is found naturally in water, plants, animals, and within the Earth. The Earth’s crust is 59 percent silica, and it makes up more than 95 percent of known rocks on the planet. When you sit on a beach, it’s silicon dioxide in the form of sand that gets between your toes. It’s even found naturally in the tissues of your body, though it’s unclear whether it serves any physiological role.
Why Is It in Food and Supplements?
Along with being found pretty much everywhere on earth, silicon dioxide is found in foods and supplements. But, why?
First, as a food additive, silicon dioxide serves as an anticaking agent. It is used to prevent clumping. In supplements, it’s used to prevent the various powdered ingredients from sticking together.
As with many food additives, consumers often have concerns about finding silicon dioxide on product labels. However, numerous studies have found no health risks associated with this particular ingredient.
Silicon dioxide is found naturally in many plants. For example, leafy green vegetables, beets, bell peppers, brown rice and oats, and alfalfa.
What the Research Says
The fact that it’s found in plants and drinking water, suggests it is safe. But in addition, research has shown that the silica we consume doesn’t accumulate in our bodies; rather, it’s flushed out by the kidneys.
While many of the studies on silica have been done on animals, they have found no link between silicon dioxide and increased risk of cancer, organ damage, or mortality. In addition, studies have found no evidence that silicon dioxide can affect reproductive health, birth weight, or body weight.
According to a paper prepared in association with WHO, the only negative health effects related to silicon dioxide have been caused by silicon deficiency. In other words, a lack of silicon dioxide may do more harm than too much.
Have Safe Limits Been Set?
Though the research doesn’t indicate any risks associated with silicon dioxide ingestion, the FDA and other global health organizations have set upper limits on its consumption. This is mainly because amounts higher than these set limits have not been sufficiently studied.
In the United States, the FDA says silicon dioxide should not exceed 2 percent of a food’s total weight.
Silicon dioxide exists naturally within the earth and our bodies. There is no evidence to suggest it is dangerous.