Aloe vera

Aloe has a very long history of use. The sap was used medicinally by the Greeks and Romans, who obtained it from the island of Socotra. The Greek physician Dioscorides recorded the use of the leaves to treat wounds in the first century AD.

Aloe had reached England by the 10th century, where it appears to have been one of the drugs recommended to Alfred the Great by the Patriarch of Jerusalem. In the early part of the 17th century, the records of the East India Company show payments for aloe being made to the King of Socotra, who held a monopoly on the production of drugs from the Socotrine aloe.

It is not known whether the Socotrine aloe obtained in Greek and Roman times was from wild or cultivated populations. Today, however, African aloe (both Socotrine and Cape) is collected from wild plants, while in the West Indies, the plants are laid out in plantations like cabbages.

To prepare Aloe vera for market, the leaves are cut near the base of 24-36 year old plants. The resulting latex is collected and concentrated to the consistency of thick honey. A true concentrate produces a clear, translucent gel, which can be applied fresh, or it can be commercially converted into a more expensive ointment.

The gel can also be fermented to produce a tonic wine, to which honey and spices are added. In India, this is used to make a drink called kurmara or asava to treat anaemia and digestive and liver disorders.

The gel can also be inhaled in steam, and the powdered leaves can be used as a laxative. There is a danger that the huge tonnages of gel now sold in the developed world will mean that aloe is regarded as a cure-all for any ailment.