Fifth International Symposium on the Role of Soy in Preventing and Treating Chronic Disease

The effect of consuming 25 g/d of soy protein on the nutrient profile of the diet has been assessed by considering the nutrient profile of soy and soy products, practical examples of substituting soy products for nonsoy products, and soy intake studies. A further consideration is the cost implication of choosing 25g/d of soy protein. Soy is low in fat, in particular saturated fat; is a good source of polyunsaturated fats (linoleic and -linolenic acid); and does not contain cholesterol. Soy is also an excellent source of protein and contains soluble dietary fiber, micronutrients, and phytochemicals. As such soy fits in well with current dietary guidelines. Practical examples in Tables 1 and 2 show that substituting soy products for nonsoy products has a favorable effect on nutrient profile. The total amount of energy and fat is higher when semiskimmed milk, low-fat yogurt products, and very lean meat are used and the amount of protein is slightly higher. The main difference is the shift toward the unfavorable saturated fatty acids and low level of PUFA with meat and dairy products. The substitution of up to half the recommended protein intake (1) with 25 g soy protein will tend to reduce the saturated fat content of the diet This is confirmed in data from the Oxford arm of the European Prospective Investigation into Cancer and Nutrition, where a highly significant trend for reduced saturated fat intake at higher levels of soymilk intake in both preand postmenopausal women was reported (2). Protein and carbohydrate intakes are largely unaffected by increased soymilk consumption. Some of soy protein items are cheaper than animal protein alternatives and although soymilk is more expensive, many of the yogurts and dessert items are comparable in cost. Overall there is potential for a healthy eating initiative that need not cost more. 1. Department of Health (1991) Dietary Reference Values for food energy and nutrients for the United Kingdom. Report on Health and Social Subjects 41. HMSO, London. 2. Verkasalo, P. K., Appleby, P. N., Davey, G. K. & Key, T. J. (2001) Soy milk intake and plasma sex hormones: a cross-sectional study in preand postmenopausal women (EPIC-Oxford). Nutr. Cancer 40: 79–86.