When the Spanish conquered the Aztec and Inca civilisations for gold in the 1500s, they also destroyed the natives' primary source of nutrition.

Amaranth was believed to have magical, medicinal properties and was incorporated into pagan Indian rituals involving human blood.

So horrified were the Spanish conquistadors, that they promptly gave orders for all amaranth crops to be burned down.

It's likely this highly nutritious plant would have become extinct if it hadn't been cultivated in a few remote Andean regions. Research in the Fifties identified its superior nutritional value and amaranth was finally recognised as having major crop potential.

With 150 million underweight pre-school children worldwide and large-scale famine in Africa, the race is on to find protein-rich grains.

These need to be adaptable and easy to grow as well as resistant to heat, drought and disease.

Amaranth not only fulfils all these criteria but contains the highest protein values of any grain and is particularly rich in two essential amino acids: Lysine and methionine.

Lysine is required for growth and bone development and aids calcium absorption. It is often used as a supplement with vitamin C and bioflavonoids to combat herpes virus infections.

Methionine is a powerful antioxidant which inactivates free radicals, protects the liver and is useful for those with food and environmental allergies.

Both amino acids are less commonly found in other grains.

Amaranth is also high in fibre and contains essential fatty acids, calcium, iron, potassium and vitamins A and C.

It is the only known food that contains between 75 and 87 per cent of total human nutritional requirements.

The cooked grain is 90 per cent digestible and therefore invaluable to infants and those recuperating from illness. It is ideal for those on gluten-free diets and useful for vegetarians looking for a high-quality protein source.

With such respectable nutritional credentials, I couldn't understand why amaranth is not more commonly known and utilised.

However, I soon realised when, cooking it for the first time. I was confronted by a gloopy looking porridge.

Ideal for breakfast, perhaps, sweetened with honey, with some added raisins, fruit and nuts. Amaranth has a sticky texture and you need to take care not to overcook it.

But it has a very pleasant, nutty taste and seems to work best when added to casseroles, soups, stews and stir-fries.

The small grains can be ground in a coffee grinder and the flour used to make cookies, bread and pasta. They can also be popped like corn and made into cereal or confectionery - these are found in various health-food stores.

It is heartening to hear aid programmes are reintroducing amaranth into the diet of indigenous peoples.

For some, such as those in Mexico, traditional farming and cooking practices are being revived after centuries of neglect.

For others, such as starving African communities, amaranth grains must be worth more than all the Inca gold and, what's more, this kind of foreign aid can't be siphoned off into Swiss bank accounts.