Food Sources High in Silica
Silicon, present in plants as silica and soluble silicates and is bound to the cellulosic cell structure (Bailey, 1981), Hydrated silica known as opaline silica or silica gel, is commonly deposited in plants in the form of particles called phytoliths.
Silica is primarily high in foods that grow underground (Potatoes, Beets). The highest amount of silica is in the skin (peel). Silica is also present in the fiber-like substances in the foods, examples: the fibers emanating from the pit of the mangoes, the fibers in the celery). Silica is also found in the bran of whole grains.
Apples, Beer, Beets, Bell peppers, Cherries, Celery, Corn, Cucumbers, Dandelion, Dried beans cooked (Chickpeas, Red Kidney beans, Urad, Moong), Eggplant, Figs, Fish, Grapes, Honey, Kelp, Leafy vegetables (Spinach, Mustard greens, Lettuce, Endives), Nettle, Nuts, and Seeds (Almonds, Peanuts, sunflower seeds, flaxseeds), Oranges, Pumpkin, Raisins, Raw Cabbage, Root vegetables (Beets, Carrots, Garlic, Ginger, Onions, Potatoes, Sweet potatoes, Fresh Turmeric), Seafood, Soybeans, Tofu, Strawberries, Tomatoes, Whole-grains (Brown Rice, Roti made of whole-grain wheat flour).
Zeolite, Alfalfa, Bamboo, Nettle, and Horsetail are commonly used in making Silica supplements.
What is the different silicon absorption in foods?
The bioavailability of silicon differs between foods: orthosilicic acid and water-soluble silicates from beverages are easily absorbed (41%), whereas phytolytic silica, present in solid plant foods, is less absorbable.
Almost all ingested silicon in food is unabsorbed. From an average of 13,6 mg in every 250 grams, only 0.068 mg (less than a 1%) of silicon is absorbed in our bodies, and the rest eliminated because opaline crystals are an inorganic thus non-absorbable silicon form. An average of 1% of dietary silica is excreted in the urine (an indicator of absorption).
On the other side, beer has a silica content of 4,8 mg/250 ml. From this, 2.06 mg of silicon is absorbed.