In nutrition, there has been a lot of buzz about soy. Soy foods are becoming increasingly common with many processed foods such as meat products, baby formula, cereal, biscuits, and cheeses, just to name a few, containing soy in some form. Soy is not always listed on the ingredients label as soy. It may also be shown as vegetable oil, lecithin, or hydrolysed vegetable protein. But is soy good for you or bad for you?
Soy is a complete protein as it contains all of the essential amino acids that the body needs. It is one of the only vegetable proteins that are listed as complete, with amaranth being the other. Amino acids are vital as they are responsible for the maintenance and repair of the body’s muscles, tendons, ligaments, organs, glands, nails, and hair. They are also responsible for helping the body to make hormones, neurotransmitters, various body fluids, and enzymes that trigger particular bodily functions.
Soy foods are nutritionally valuable as they are high in fibre. As well, they are high in folic acid, B vitamins, potassium and iron. Just half a cup of tofu can provide you with much of your daily requirements of protein, calcium, and iron. Soy is also very high in isoflavones, which have strong antioxidant properties. These antioxidant properties means that soy is useful for repairing and preventing damage that may occur as a result of pollution, exposure to the sun and even the free radicals that are produced by normal bodily functions.
Soymilk is rich in calcium, so it is a good substitute for people that are lactose intolerant. Soy foods can help to protect and build bone density in women that have gone through menopause, therefore lowering the risk of osteoporosis (see osteoporosis treatments). Soy may also be helpful for males as a substance that the body releases after eating soy binds to dihydrotestosterone (DHT), inhibiting and stopping the hormone that causes male pattern baldness, acne, and hirsutism.
Soy is noted for its ability to lower the levels of cholesterol in the blood. It particularly works on the “bad” cholesterol, known as LDL cholesterol.
Traditional soy foods are the best as they are relatively intact, the whole bean is being used, and they are usually fermented. These forms of soy include tofu, tempeh, miso, nato, and soy sauce.
One problem that may have occurred as a result of soy’s popularity is that many manufacturers do not use the whole soy product in their foods. Instead, they use the protein with its isoflavones, so they can still claim the health benefits of soy without having to use the whole product. The protein with the isoflavones is called soy isolates.
Because so many manufacturers use soy isolates, children that have been fed soy formula as infants may have received as much estrogen as what is in contained in five contraceptive pills, on a daily basis. Because of this, it is a good idea that soy formula be used only for children that are lactose intolerant or are unable to be breastfed.
There are also other doubts about the benefits of soy. One such doubt is if whether soy products will actually lower a person’s cholesterol levels. Another doubt is whether soy or soy isoflavones are useful for reducing menopausal symptoms such as hot flushes.
Soy foods also increase the body’s need for vitamin D, and it requires the body to need more vitamin B12. This is because the body is unable to utilise the vitamin B12 that is present in soy. Soybeans are high in phytates, an organic acid that makes it difficult for the body to absorb essential minerals such as calcium, iron, magnesium, and zinc. Phytates are resistant to cooking and can only be reduced by fermentation techniques such as those used to make miso or tempeh.