Ginger represents the ultimate in healthy eating. It is said to warm the internal organs, ease depression, and cure ailments from colds to nausea. It stops food going off and tastes good too, says April Joyce.

In the East, where food is revered for its therapeutic properties as much as for its richness and flavour, no self-respecting kitchen is complete without fresh root ginger. What this gnarled, bulb-like underground stem lacks in appearance, it makes up for in its wealth of flavour, aroma and multi-medicinal qualities.

What we think of as 'root ginger' is actually an underground stem or rhizome which comes from the perennial plant Zingiber officinale. It has been cultivated for so long that its origins are now obscure, but it was probably first grown in Southeast Asia. Ginger is now cultivated throughout Asia, Australia, Africa and South America. There are a dozen different varieties and its delicate green leaves, resembling baby spinach, can be eaten in salads.

Its deliciously hot sweet tang has long been a key element of traditional Asian food and, of course, there is always the good old-fashioned Ginger Nut. But it is the role of ginger in contemporary East-West cuisine and complementary medicine that has raised its profile.

Fresh root ginger is available in supermarkets and corner shops everywhere. Ginger was one of the first spices to arrive in Britain. It came here in the 10th century, though it had been esteemed by the Greeks and Romans before then. It reached its zenith in the 15th century, when it was used both for culinary purposes and as a cure for the plague.

In India and the East, ginger is used in cookery as much for its anti-bacterial properties, which help counter the putrefaction of meat and fish. "It is an amazing spice that not only brings life to food but has strong medicinal agents," says Atul Kochhar, head chef of London's north-west Indian restaurant Tamarind.

In Indian Ayurvedic medicine, great emphasis is placed on the healing powers of foods, herbs and spices and each dish is planned with medicinal benefits in mind. Atul Kochhar enhances the anti-viral qualities of ginger by combining it with garlic. "The sweetness of ginger and the pungency of garlic complement each other perfectly, and their anti-viral qualities are an excellent cure for colds and flu."

Ginger has been used in Chinese herbal medicine for centuries to purge the body of colds and viruses and as a stimulating tonic for digestive disorders and the female reproductive system. Brewed as a tea, it induces sweating, which helps fevers run their course. It also tones and helps boost the immune system. Fresh ginger grated into hot lemon and honey is a soothing way to fight off colds and discharge mucus.

At the Acumedic Centre for Chinese Medicine, Dr Jian Guo uses ginger in the treatment of period pains, digestive disorders, nausea and colds. "Ginger is excellent for people with what we call a 'cold body'," she says. "It has a warming, stimulating effect on the internal organs, soothing a weak digestive system and raising the body's temperature to fight infection." In the United States, scientists discovered that ginger's antibiotic qualities killed the salmonella bug in test-tube trials, and some clinical trials have proved it to be as effective as standard drugs in treating travel sickness and nausea in pregnancy.

The essential oil of ginger diluted in a base oil is used in aromatherapy to ease muscle cramp and is especially good in winter to ease the pain of chilblains. Massaged into the kidney area and spinal column, it boosts poor circulation and its revitalising qualities are believed to help lift spirits and ease depression.

Ginger: getting the best When buying ginger, fresh is best for robustness of flavour, although ground ginger makes for a smoother curry paste. According to Atul Kochhar, chopped is better than crushed when frying, to create a wider surface for oil to penetrate.

Always look out for a root with smooth skin and as few twists and joints as possible. If it is wrinkled, it is drying out and will be woody inside. Fresh ginger can be kept in an airy container alongside garlic or in the fridge. A novel way of storing this spice is to bury it in sand. It can be used as required and is said to continue to grow in the meantime, giving you a continuous supply.