Press Release WHO/4 12 January 1998   CAROTENOID PILLS SHOULD NOT BE PROMOTED FOR CANCER PREVENTION   Scientists of the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) cautioned today against using dietary supplements - plant constituents of fresh fruits and vegetables B for cancer prevention. In particular, they warned against the promotion of carotenoid pills. Fresh fruits and vegetables, they said, remain the first line of defence against the disease. During the last two decades, many epidemiological studies in different countries showed that a diet rich in fruits and vegetables lowers the risk of developing cancer. The results of these studies led to a widespread belief that plant constituents, such as carotenoids and beta-carotene in particular, can produce a protective effect against cancer. In December 1997, a working group of 23 scientists from 10 countries met at IARC in Lyon, France, to evaluate all the published data on the health effects of carotenoids, including the results of clinical trials in which high doses of beta-carotene were given to reduce cancer incidence and mortality in healthy populations. "In none of these trials did the drug have a significant preventive effect," said Dr Harri Vainio, Chief of the Chemoprevention Unit at IARC. "Moreover, when given to regularly smoking volunteers, it was shown to increase the risk of lung cancer and mortality from cardiovascular diseases."  "Our group came to the conclusion that, until further information becomes available on how beta-carotene and other carotenoids influence the processes leading to cancer, none of these substances should be promoted to the general population as a tumour-preventive treatment. It appears at present, that cancer prevention by fresh fruits and vegetables remains more effective than taking one or several of their constituents as dietary supplements," said Dr Vainio. The results of the meeting will be published as Volume 2 of the IARC Handbooks of Cancer Prevention, a recently established publication series concentrating on the prevention of cancer.   For further information, please contact Igor Rozov, Health Communications and public Relations, WHO, Geneva. Telephone (+41 22) 791 2532. Fax (+41 22) 791 4858. Email rozovi@who.ch. Or you may also contact Dr. Harri Vainio, Chief, Cheprevention Unit, IARC: Fax 33 472 73 83 19, email Vainio@iarc.fr All WHO Press Releases, Fact Sheets and features as well as other information on this subject can be obtained on the Internet on the WHO home page at http://www.who.ch/.   ______________________________________________________________________ For more information, please contact: Igor Rozov, Health Communications and Public Relations, WHO, Geneva, tel. (4122) 791 2532, fax (4122) 791 4858, e-mail rozovi@who.ch , or Dr Harri Vainio, Chief. Chemoprevention Unit, IARC, Fax: 33 472 73 83 19 , e-mail Vainio@iarc.fr