Splendour in the grass
Smoking marijuana doesn't increase the risk of developing lung cancer - much to the surprise of researchers. A University of California Los Angeles study of more than 2,000 people found no increased risk even among the heaviest users, whereas there was a 20-fold greater risk for people who smoke two or more packs of cigarettes a day. This is despite marijuana tar containing 50 per cent more chemicals linked to lung cancer than tobacco tar. Marijuana also tends to be more loosely packed, allowing more particles to be inhaled. And marijuana users typically hold the smoke in their lungs four times longer than tobacco users. Team leader Donald Tashkin told Reuters that a psychotropic chemical in marijuana, tetra-hydrocannabinol, may encourage damaged cells to die off before they become cancerous.
Herb extract slows cancer
Popular herbal remedy Ginkgo biloba may help fight brain and breast tumours, according to studies of mice at Georgetown University Medical Centre, in Washington, DC. Treating mice with an extract of the herb before and after they were implanted with human cancer cells significantly slowed the growth of breast tumours and temporarily reduced the size of brain tumours, according to healthday.com. 'It's very encouraging that Ginkgo biloba appeared to reduce the aggressiveness of these cancers,' says team leader Vassilios Papadopoulos. The findings apply only to mice so far, although Papadopoulos says the results suggest the extract could eventually be used to prevent early-stage diseases spreading.
Origin of Aids found
Scientists say they have tracked the original source of the Aids virus to a group of chimpanzees in Cameroon. Findings, published in Science magazine, by a US-British-French team 'show for the first time a clear picture of the origin of HIV-1 and the seeds of the Aids pandemic'. The simian immunodeficiency virus probably infected hunters who ate Pan troglodytes troglodytes chimpanzee meat. The human virus first appeared in Kinshasa, 1,000km away, about 25 years ago. According to AFP, Aids has since killed 26 million people, and more than 40 million have been infected with HIV.