Scientists have discovered that galanthamine, a substance that occurs in daffodil and snowdrop bulbs, can help alleviate the progressive degeneration of the brain - beginning with failing memory - that the disease causes. Shire Pharmaceuticals of Andover, Hampshire, revealed last spring that the results of initial tests on a drug made from the compound were promising enough to justify full clinical trials, which began in the summer.
This is not just a potential boon for the afflicted. For East Anglian bulb growers, squeezed by competition from Holland to the east and Cornwall to the west, it could be a lucrative new source of business. The contract has gone to Lingarden, a growers' co-operative based near Spalding in Lincolnshire.
Ten tons of daffodil bulbs produce one kilogram of galanthamine. Bob Out, Dutch-born managing director of Lingarden, estimates that by the end of the decade, when the drug may go into full production, an extra 20,000 tons of bulbs a year would be needed. At the current price of pounds 600 a ton, this amounts to a pounds 12m boost to the region's economy.
"It will be very good for the area and I will need to find a lot of new people to grow them for me," he says.
To produce this quantity, Mr Out will eventually require 7,000 acres of new bulb fields - a huge increase given that his co-operative currently has fewer than 4,000 acres of daffodils planted, of a total of 10,000 acres given over to the flower in the whole of Britain. He is finding new sources of supply not just among the traditional flower growers, but also on farms formerly devoted to food crops.
Each bulb is left in the ground for two years, after which time, two or three will have developed where the original one was planted. At this early stage, only a few are being sent to Edinburgh, where the pharmaceuticals company Macfarlan Smith extracts the galanthamine for Shire, who will make and market the product. The majority are replanted, which means that 1,000 acres of bulbs will expand to 2,500 acres after two years.
A spokesman for Shire said last week that the drug was now in the third phase of clinical studies, with a dossier being built up to present to the regulatory authorities. Tests will be conducted on 560 patients in seven European countries.
Galanthamine is the bitter substance in daffodil and snowdrop bulbs that deters animals from eating them. In humans, it supplies a chemical that stimulates communication between brain cells impaired by the onset of Alzheimer's disease. (Snowdrop bulbs are not used because they are too small.) Apart from the half-million British sufferers, there are an estimated four million in the United States, and the numbers increase as people tend to live longer. Older people are worst- affected by the disease.
Harry Cayton, executive director of the Alzheimer's Disease Society, is optimistic about the drug. "We're watching the development with hope and interest," he says. "Galanthamine is one of a group of compounds being researched as a treatment for one of the symptoms of Alzheimer's. We think it's promising, particularly because there seems to be the possibility of reduced side-effects."
A drug called tacrine, sold in the US and elsewhere as Cognex, treats Alzheimer's disease symptoms in a similar way to galanthamine, but can cause nausea and liver damage, and it has not yet been approved in Britain. Preliminary research suggests that galanthamine does not trigger these complications to the same extent.
Mr Cayton stresses that the drug will not cure or prevent the disease, merely reduce the symptoms and improve the patient's quality of life. "The damage done to the brain in the early stages is too great for a cure. The underlying disease process will continue -all you've done is suppress the symptoms. "
It is a coincidence, but an apt one, that the society has chosen a floral theme for its fund-raising effort on this year's World Alzheimer's Day on 21 September. It will be called "Don't Forget the Flowers Day", when many florists will be selling special bouquets for pounds 7.99 each, with pounds 1 on every sale going to the Society. It is the wrong time of year for the bouquet to include daffodils, the new source of hope for sufferers.