What’s so good about … soya?
Soya has been in the news lately. First, it was named as a key ingredient of a ‘diet to stop heart disease’ that made the front page of the Daily Express. Then it appeared that a soya supplement, Natural S-equol, has been shown to improve the appearance of crow’s feet wrinkles in women, according to a study published in the journal Menopause.
So that seemed like two good reasons to find out a bit more about soya. What I discovered was, to me anyway, really surprising:
1 We are already eating more soya than most of us probably realise. According to the organisation Allergy UK, soya in its various forms, such as flour, oil, gum, flavouring and starch, is present in up to 60% of processed food, from baby foods to ready meals and desserts.
2 Soya is used so widely because it is versatile: crushed beans can be made into milk, and then into dairy-type products such as cheese, yogurt and curds (known as tofu). It is fermented to make Asian staple flavourings such as soy sauce, tamari and miso. Made into flour and reconstituted, soya makes textured vegetable protein, a meat alternative. Soya also features in behind-the-scenes ingredients such as emulsifiers (soya lecithin) and protein fillers.
3 Young soya beans, known as edamame, can be boiled and eaten as a vegetable – allegedly Victoria Beckham’s favourite.
4 Soya contains compounds called isoflavones which are often promoted as beneficial for menopausal symptoms in women – and potentially also osteoporosis – although NHS Choices says there is no medical evidence that they are effective.
5 The presence of soya must be listed on food labels in the EU because it is identified as a major food allergen. The Allergy UK website has a useful guide to this.
6 Soya protein has been shown in several studies to help to lower ‘bad’ cholesterol in the blood, although exactly how it does this is not clear. The British Heart Foundation recommends eating at least 25g of soya protein per day to help reduce blood cholesterol. The Food and Drug Administration in the USA also recommends this but it is not part of official UK dietary guidelines.
7 The ‘diet to beat heart disease’ that appeared in the news comes from Heart UK, a charity that focuses on cholesterol control. The idea came from a study carried out in Canada, in which a ‘portfolio diet’ of foods containing plant sterols, soya protein, soluble fibre and nuts was shown to reduce ‘bad’ cholesterol more effectively than a standard healthy diet. This study was published in the Journal of the American Medical Association.
8 The Heart UK version of the diet, called the Ultimate Cholesterol-Lowering Plan, is sponsored by the soya product manufacturer Alpro, which has just launched a new variant of its soya milk that has added plant sterols (the compounds that are found in cholesterol-lowering spreads and drinks like Benecol).
9 Eating products that may have cholesterol-lowering properties is not the most important element of a healthy lifestyle; eating less saturated fat, cutting out trans fats, eating soluble fibre (from sources such as fruit and oats) and exercising regularly are all key, says NHS Choices.
10 If you are watching your weight as well as your cholesterol, soya products such as desserts and milk are not necessarily lower in calories than dairy versions. Cost might be an issue too; for example a litre of Alpro Soya Plus milk costs £1.35 at Tesco, compared to 89p for 1.14 litres of semi-skimmed dairy milk.