It was hailed as a superfood that could fight breast cancer, strengthen bones and ease the menopause. Once thought of as exotic, today soya can be found in a variety of guises on supermarket shelves, from dairy-free milk and yogurt to vegan cheese and tofu.
Soya was first cultivated in China, where it was used as medicine and in cooking. Last year, more than one million tons of it were imported to the UK. However, there is mounting evidence that soya could, in fact, pose a serious health risk. Experts claim soya foods might lower testosterone levels in men, hamper thyroid function, cause weight gain and disrupt hormones.
Hailing from the same family as beans, peas and lentils, soybeans are crushed to form soybean meal, which is then used to make edible soya products. It contains all the essential amino acids to build protein in our bodies, and many vegetarians opt for soy products as a way of upping their daily protein intake. Surprisingly, according to food-industry estimates, it is also found in 60 per cent of processed foods, adding bulk, flavour and texture.
Breakfast cereals, cereal bars and biscuits, cheese, cakes, dairy desserts, gravies, noodles, pastries, soups, sausage casings, sauces and sandwich spreads, to name just a few, often contain soya. It appears on food labels as 'soya flour', 'hydrolysed vegetable protein', 'soy protein isolate', 'protein concentrate', 'textured vegetable protein', 'vegetable oil', 'plant sterols', or the emulsifier 'lecithin'.
Millions believe it to be a healthy option, providing protein with no saturated fat and without the risk of raising cholesterol levels. Yet it seems the very properties that made soya so attractive could also make it a health threat.