Phytate, and phytic acid, are the common names for a molecule called inositol hexaphosphate (IP6).This compound has the molecular formula C6H18O24P6 and a molecular weight of 660.08 grams per mole. IP6 has a six carbon ring structure, with phosphate groups attached to each carbon. Both plants and animals create and utilize IP6 for cellular functions like vesicle recycling and membrane maintenance. Plants tend to synthesize large amounts of IP6 as a phosphorus storage strategy, concentrating it in the hulls of seeds and coating of beans.
Phytates Inhibit Absorption of Minerals
Phytates have been clinically shown to inhibit the absorption of dietary minerals like calcium, copper, magnesium, iron, and zinc. These molecules attach to minerals in the digestive tract and make them unavailable to the body. They are then excreted in the waste. Phytates keep the body from using minerals from the diet. Diet phytate levels above 10% tend to drastically reduce growth and nutrient intake. For some populations like vegetarians and pregnant or lactating women, this adds another challenge besides simply finding and eating foods high in the minerals. Studies show that this inhibition may be overcome to a degree by taking additional vitamin C or calcium.
Phytates may Prevent Cancer and Lower Cholesterol
While iron is a crucial need of the body, it is also a powerful oxidant. Phytates are thought to exhibit antioxidant properties by sequestering this iron before it can be involved in damaging processes -especially in the colon. Phytates appear to inhibit tumor formation, and even cause cancerous cells to revert back to their former types. They may also improve the effectiveness of chemotherapy drugs when taken together. Phytates and green tea (Camellia sinensis) have a synergistic effect against select cancers when taken together. Phytates have been shown to reduce the digestion of starch by at least 50% and reduce the overall glycemic index of other foods they are eaten with. They also decrease cholesterol and triglyceride production by the liver.
Common Sources of Phytates
Plant sources high in phytates include:
- Unfermented Soy (soy beans, soy milk, flour, edamame, tofu)
- Flax Seed
- Beans
- Brown Rice
- Corn
- Peanuts
- Wheat Bran
- Sesame Seeds
Soy milk and tofu are highly concentrated sources of phytates and should probably be avoided by children, pregnant or lactating women, and those with mineral deficiencies.
Recommendations
Currently, researchers are recommending the following dosages (preferably from diet):
- Cancer Prevention: 1-2 grams / day
- Increased Cancer Risk: 4 grams / day
- Concurrent Cancer Treatment: 8 grams / day (With physician supervision)
A dynamic picture is emerging regarding phytates in the diet. While they inhibit growth and mineral absorption, they also exhibit a protective function against certain types of cancer. Since the body normally has no way of excreting excess minerals like iron and zinc, phytates may play a dietary role in inhibiting excesses of these from being absorbed.
Supplimentary Resources:
BioSci Biotech Biochem 2004 Jun; 68 (6) 1379-81
Cancer 1985 Aug 15; 56 (4):717-8
Carcinogenesis, 1997 Oct 18 (10): 2023-6
Journal of Nutrition 2003 Nov; 133: 3778s-3784s
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