How good is soya?

Faye Axford © GoodnessDirect 2007

Soya is a versatile, nutritious food that offers a wide range of health benefits and does not contain saturated animal fat, animal protein, cholesterol, animal hormones or growth factors which have all been linked to many illnesses and diseases.

It contains all eight essential amino acids and is a good source of polyunsaturated fatty acids including omega 3, disease-busting antioxidants, B vitamins (including folate), iron and is free from cholesterol. Calcium-fortified soya milk and tofu provide a valuable source of this important mineral.

Many soya foods also contain fibre which is important for good bowel health and can lower cholesterol.

Health benefits associated with soya are thought to be caused by the action of soya isoflavones which are a type of phytoestrogen or plant hormone. Many studies show that soya foods can reduce the frequency and severity of hot flushes and other menopausal symptoms. Because the Japanese diet is rich in soya the women suffer less from menopausal symptoms which suggests it may be an alternative to hormone replacement therapy. Post-menopausal women with the highest intake of soya foods also have the highest bone mineral density. Human trials in other parts of the world have shown that soya protein may reduce the risk of osteoporosis.

The UK government's 'Joint Health Claims Initiative' has approved the health claim that 'the inclusion of at least 25 grams soya protein per day as part of a diet low in saturated fat can help reduce blood cholesterol'.

Studies from China (and of Asian-American women) indicate that having a high soya intake can reduce the risk of breast cancer. Similarly, a large scale study in 59 countries found that overall soya products did protect against prostate cancer. Evidence suggests that a moderate amount of soya is much more likely to be of benefit to health rather than harmful, both in terms of breast and prostate cancer risk and other chronic diseases.

Other items of interest

A great many people ask if it safe to give soya-based infant formulas to babies. Studies on adults raised on soya showed no detrimental effects to their health. A publication in the Nutrition Review found that growth, sexual development and reproductive ability was normal in people who consumed soya formula as infants and concluded that it continued to be a safe, nutritionally complete feeding option for most infants.

Another fantastic bonus is that several studies indicate that soya isoflavones may improve both short- and long-term memory, mental flexibility and planning. This benefit may be restricted to those under the age of 65.