Chilli, turmeric and other spices are often claimed to have health benefits or even the ability to "boost our immune system". But can spices really add any health benefits to our food, or help us ward off illness? Spices have been a part of our diets for thousands of years – it's second nature to sprinkle our chips with pepper, sip on ginger tea and add chillies to our meals. But recently, some spices have been unofficially promoted from everyday culinary staples to all-healing superfoods. (BBC News)