Those who like very hot curry may unwittingly be doing themselves a favour. Turmeric, the vivid yellow spice which is the main constituent of curry powder, is reputed to have numerous health-giving properties. Enthusiasts say that it is good for circulation, a powerful aid to digestion and can even lower cholesterol levels.

This apparent superspice, called haldi in Hindi, is the powdered rhizomes of the plant Curcurma longa, grown widely throughout southern and eastern Asia. It is still associated by most Europeans with the culinary rather than the healing arts. But it is beginning to attract attention in the West: last week an attempt by the University of Mississippi to patent its healing properties was thrown out by the US Patent Office - to the delight of many Indians - on the grounds that turmeric is already a part of the traditional Indian knowledge base.

Like other spices, it has traditionally been used in cooking by India's rural communities to help prevent gastric infection from bad food (richer families have tended not to favour hot curries for the simple reason they have access to fresher meat and fish). It is also used by Hakims, India's traditional healers, as part of the ancient system of Ayurvedic medicine, itself fast becoming a cult in the West; and is drunk with hot milk in Indian households to stanch bleeding.

Along with other spices - cayenne, cumin, ginger, cardamom - turmeric is fast becoming popular with European herbalists, particularly for inflammatory conditions such as arthritis, asthma and eczema, and also for gastric and circulation problems.

But does it work?

Most of the research on turmeric has taken place in India, not much of it in the form of clinically controlled trials on humans. But laboratory research has confirmed that the spice does have anti-inflammatory properties - hence its use in the treatment of inflammatory disorders and its usefulness in reducing bruises and swellings. It is also anti-bacterial - which is why it can prevent stomach upsets - and research has also found it to be anti-oxidant, a quality which promotes healthy circulation and lowers cholesterol levels.

Turmeric's active constituent is called curcumin, but like many other "warming" spices it also contains volatile aromatic oil which helps to reduce irritability in the gut, so it is good for gastric health. Like most herbs it is probably best suited to those with chronic rather than acute ailments, although in the future, if its active constituent is synthesised, it could be developed into a very powerful drug. It can be taken internally (as a capsule, or drink or powder mixed with food), or used as a paste for skin complaints.

Most herbal retailers sell a medicinal version of turmeric for use in the home - the spice sold for culinary purposes may have been processed differently. There are no known contra indications, although turmeric can apparently increase sensitivity to sunlightn

Cherrill Hicks