Pubdate: Fri, 4 Aug 2000 Source: Financial Times (UK) Copyright: The Financial Times Limited 2000 Contact: letters.editor@ft.com Address: 1 Southwark Bridge, London, SE1 9HL, UK Fax: +44 171 873 3922 Website: http://www.ft.com/ Author: Vanessa Houlder

MARIJUANA MAY BE JUST THE THING FOR JOINTS

The medicinal use of marijuana remains controversial. But the evidence is piling up concerning the medical effectiveness of some of its constituents. The latest set of findings suggest that one of its components could ease the stiff joints caused by arthritis.

Research supported by the Arthritis Research Campaign suggests that cannabidiol - a natural constituent of cannabis that has no mind-altering effects in it natural form - may be useful for treating rheumatoid arthritis and other chronic inflammatory diseases.

Scientists at the Kennedy Institute of Rheumatology in London and Hebrew University in Jerusalem discovered that cannabidiol suppressed the immune response of mice with a disease resembling human arthritis. It protected the mice from severe damage to their joints and markedly improved their condition, according to the Proceedings of the National Academy of Sciences, a US journal.

* As if farmers did not have enough to worry about, new evidence suggests that climate change will have a particularly marked effect on agricultural land. Research published today concludes that farming may make grasslands more vulnerable to the effects of global warming by disturbing the overall make-up of their ecosystems.

A team of British scientists mimicked the effects of global warming on plots of land using heated cables, hoses with spray nozzles and automated covers that slid over the plots when it rained.

The researchers, who are mostly from the University of Sheffield, tested two areas of limestone grasslands: an ancient sheep pasture in Derbyshire and a field in Oxfordshire that was, until recently, used for arable crops.

The results were worrying. They found that the more fertile, recently farmed land in Oxfordshire was much more vulnerable to the effects of climate change - with marked variations in the amount and composition of the vegetation - than the undisturbed land in Derbyshire. As more land goes into production to feed the world's expanding population, "human impacts may be making whole landscapes more responsive to climate change", say the scientists in today's edition of Science, the US journal.